5th International Conference on Reanalysis (ICR5)

13–17 November 2017, Rome

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ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 2 Introduction

It is our pleasure to welcome the Climate research has benefited over the • Status and plans for future reanalyses • Evaluation of reanalyses reanalysis community at the 5th years from the continuing development Global and regional production, inclusive Comparisons with observations, other International Conference on Reanalysis of reanalysis. As reanalysis datasets of all WCRP thematic areas: atmosphere, types of analysis and models, inter- (ICR5). We are delighted that we are become more diverse (atmosphere, land, ocean and cryosphere – Session comparisons, diagnostics – Session all able to come together in Rome. ocean and land components), more organizers: Mike Bosilovich (NASA organizers: Franco Desiato (ISPRA), This five-day international conference complete (moving towards Earth-system GMAO), Shinya Kobayashi (JMA), Masatomo Fujiwara (Hokkaido is the worldwide leading event for the coupled reanalysis), more detailed, and Simona Masina (CMCC) University), Sonia Seneviratne (ETH), continuing development of reanalysis of longer timespan, community efforts Adrian Simmons (ECMWF) • Observations for reanalyses for climate research, which provides a to evaluate and intercompare them Preparation, organization in large • Applications of reanalyses comprehensive numerical description become more important. archives, data rescue, reanalysis Generating time-series of Essential of the recent climate on a global scale. The conference brings together feedback – Session organizers: Climate Variables for climate Climate reanalysis data is used by public reanalysis producers, observation Marie Doutriaux-Boucher (EUMETSAT), monitoring, validation of third-party services, companies and organisations. providers, numerical modellers and Pierre-Philippe Mathieu (ESA), Nick products, environmental planning It provides the means to assess climate the user community to review current Rayner (Met Office) and policies, adaptation and mitigation trends and the changing climate. reanalysis activities and to discuss policies, climate services, industry, • Methods for reanalyses ICR5 provides us the opportunity user needs for future reanalyses. scientific research and education, other Data assimilation, Earth-system to review progress and discuss future applications – Session organizers: Through this conference, we aim to coupling, uncertainty estimation, plans in key areas, including: Andrea Kaiser-Weiss (DWD), Carolin assess the merits and review the challenges specific to regional Richter (WMO), Michel Rixen (WCRP), • Status of current production systems progress in reanalyses, to monitor reanalyses – Session organizers: Jean-Noël Thépaut (C3S) • Observation rescue activities climate variations and support policy Magdalena Alonso-Balmaseda makers to develop adaptation policies, (ECMWF), Gil Compo (CU/CIRES & • Developments in observational The 5th International Conference on and to provide complementary NOAA), Dick Dee (C3S), Zhiquan Liu databases Reanalysis (ICR5) is organised by information to other climate sources. (NCAR & CMA) • Developments in data assimilation ECMWF’s Copernicus Climate Change The Scientific Organizing Committee, co- Service (C3S) and the WMO World • Applications, user requirements chaired by Roberto Buizza (ECMWF) and Climate Research Programme (WCRP). and feedback Paul Poli (Météo-France), has structured We look forward to meeting you! • Plans for future reanalyses the conference around five main topics. The ICR5 Organisation Committee

We would like to thank all our partners and supporters of the 5th International Conference on Reanalysis in Rome:

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ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 3 Monday 13 November

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 10.30–11.30am ICR5 Media Briefing 3.45–4pm R.02 State-of-the-art Atmospheric Reanalysis Hans Hersbach at ECMWF (ECMWF) 1pm Start of the Conference 4– 4.15pm R.03 Earth System Data Assimilation and Annarita Mariotti 1–1.15pm W.01 Welcome/Opening Roberto Buizza Reanalysis Efforts Supported by the NOAA (NOAA) (ECMWF) and Paul Poli Climate Program Office’s MAPP Program (Météo-France) 4.15–4.30pm R.04 Status and plans for reanalysis at the Ron Gelaro 1.15–1.30pm W.02 Address from Copernicus Jean-Noel Thépaut and NASA Global Modeling and Assimilation Office (NASA GMAO) Dick Dee (C3S-ECMWF) 4.30–4.45pm R.05 Reanalysis at the Japan Meteorological Shinya Kobayashi 1.30–1.45pm W.03 Address from WMO/WCRP Deon Terblanche (WMO) Agency (JMA) 1.45–2pm W.04 Address from Italian Rep to WMO Silvio Cau (Director, 4.45–5pm R.06 Improvements in the Twentieth Century Laura Slivinski Italian Meteorological Reanalysis Version 3 (CU/CIRES & NOAA) Service) 5–5.15pm R.07 CMA Global Reanalysis: Ziquan Liu (CMA and 2–2.30pm Invited Keynote Adrian Simmons Status and Plans NCAR) K.1 Reanalysis: Past, Present, and Future (ECMWF) 5.15–5.30pm R.08 The CMEMS global and regional ocean Marie Drevillon 2.30–3pm Invited Talk Hisashi Nakamura reanalyses: towards a consistent set of high (Mercator Ocean) R.01 On the Significance of Using High- (University of Tokyo) resolution ocean reanalyses for operational Resolution Sea-Surface Temperature in oceanography users and ocean state Atmospheric Reanalysis Production monitoring 3–3.45pm Group photo and coffee break 5.30–5.45pm R.09 The CMCC Global Ocean Reanalysis Andrea Storto 2.30–6pm Section 1 – Status and plans of reanalysis System (C- GLORS): a multi-purpose family (CMCC) productions of eddy-permitting ocean reanalyses Chairs: Michael Bosilovich (NASA GMAO), 5.45–6pm R.10 CERA-SAT: coupled reanalysis in the Dinand Schepers Shinya Kobayashi (JMA), Simona Masina satellite-era (ECMWF) (CMCC) 6 –7.30pm Ice-breaker (drinks and finger food)

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 4 Tuesday 14 November

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 9–9.45am Invited Keynote Sonia Seneviratne 11.15 –11.30am R.14 Reanalyses of Atmospheric Composition Antje Inness (ECMWF) K.2 Future Earth-System reanalyses: (ETH Zürich) at ECMWF: from MACC to CAMS A land perspective 11.30am–12.15pm Section 2 – Observations for reanalyses 9.45 –11.15am Section 1 (continued) – Status and plans Chairs: Stefan Brönnimann (University of of reanalysis productions Bern), Nick Rayner (Met Office) Chairs: Michael Bosilovich (NASA GMAO), Shinya Kobayashi (JMA), Simona Masina 11.30am-12pm O.01 (Invited Talk) Preparing ocean Nick Rayner (Met Office) (CMCC) observations for reanalysis 9.45–10am R.11 Improving the representation of the David Bromwich 12–12.15pm O.02 Data rescue activities to support Manola Brunet Greater Arctic with ASRv2 (Ohio State University) reanalysis and climate services: the EU- (Universitat Rovira funded UERRA and EURO4M projects i Virgili, Tarragona) 10–10.15am R.12 BARRA: a high-resolution Atmospheric Chun-Hsu Su (Australia approaches and outcomes Reanalysis for 1990-2016 over Australia Bureau of Meteorology) 12.15–12.30pm Introduction to Poster Session # 1 10.15–10.30am R.13 PRECISE – Production of a regional Semjon Schimanke Reanalysis for Europe within the Copernicus (Swedish 12.30–2pm Lunch and Poster Session # 1 climate change Services Meteorological and Posters on Status and plans of reanalysis Hydrological Institute) productions, Observations for reanalyses, and Methods for reanalyses with authors 10.30–11.15am Coffee break standing in front of poster from 1pm to 2pm

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 5 Tuesday 14 November continued

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 2–3.45pm Section 2 (continued) – Observations 3–3.15pm O.07 EUMETSAT Data Records in Support Jörg Schulz for reanalyses of Reanalysis (EUMETSAT) Chairs: Stefan Brönnimann (University of 3.15–3.30pm O.08 A Fundamental Climate Data Record Karsten Fennig Bern), Nick Rayner (Met Office) of SSM/I, SSMIS, and SMMR brightness (DWD) 2–2.15pm O.03 Data Recovery Effort of Nimbus era James Johnson temperatures Observations by the NASA GES DISC (NASA/GSFC) 3.30-3.45pm O.09 Observing Mass Variability in the Henryk Dobslaw 2.15–2.30pm O.04 Homogenized radiosonde temperature Leopold Haimberger Earth System with the Satellite Gravity (GFZ Potsdam) data for climate reanalyses (University of Vienna) Missions GRACE and GRACE-FO 2.30–2.45pm O.05 The Copernicus Climate Change Service Peter Thorne 3.45-4.30pm Coffee break Global Land and Marine Observations (Maynooth University) 4.30–6pm Panel discussion – Reanalysis: from Moderator: Deon Database: Plans and progress to date research challenges to operational Terblanche, Acting 2.45–3pm O.06 The benefits for reanalysis of Elizabeth Kent (National applications and services Director, WCRP reprocessing the surface marine climate Oceanography Centre) record

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 6 Wednesday 15 November

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 9am–12.15pm Section 3 – Methods for reanalyses 11.15 –11.30am M.06 A Method for Snow Reanalysis: Manuela Girotto Chairs: Magdalena Alonso-Balmaseda The Sierra Nevada (USA) (NASA/GSFC) (ECMWF), Gil Compo (CU/CIRES & NOAA), Dick Dee (C3S), Zhiquan Liu (NCAR & CMA) 11.30–11.45am M.07 Atmospheric reanalysis for multi Kei Yoshimura centuries using historical weather archives (University of Tokyo) 9–9.30am M.01 (Invited Talk) Dynamically and Patrick Heimbach and isotopic proxies kinematically consistent global ocean state (University of and parameter estimation in support of Texas at Austin) 11.45am–12pm M.08 Paleoclimate reanalyses as a tool Hugues Goosse, climate research to understand the signal recorded by (Université de Louvain) observations over the past millennium 9.30–9.45am M.02 Uncertainty estimation in modern András Horányi reanalysis systems (ECMWF) 12–12.15pm M.09 A global climate reconstruction using Stefan Brönnimann data assimilation (University of Bern) 9.45–10am M.03 Impact of Optimal Assimilation Windows Shaoqing Zhang in Coupled Data Assimilation on AMOC (Ocean University 12.15–12.30pm Introduction to Poster Session # 2 Analysis of China) 12.30–2pm Lunch and Poster Session # 2 10–10.15am M.04 The ECMWF weak-constraint 4D-Var Jacky Goddard Posters on Evaluation and intercomparisons formulation and a comparison between 12 (ECMWF) of reanalyses with authors standing in front and 24 hour assimilation window length of poster from 1pm to 2pm to produce recommendations for future 2–2.30pm Section 3 (continued) – Methods reanalysis as part of the ERACLIM2 project for reanalyses 10.15–10.30am M.05 Using hybrid data assimilation for Amal El Akkraoui (NASA Chairs: Magdalena Alonso-Balmaseda reanalyses GMAO) (ECMWF), Gil Compo (CU/CIRES & NOAA), Dick Dee (C3S), Zhiquan Liu (NCAR & CMA) 10.30–11.15am Coffee break 2–2.15pm M.10 Reanalysis in the Whole Atmosphere Valery Yudin Models: From Nudging Techniques to Data (CU/CIRES & NOAA) Analysis in the Mesosphere and Lower Thermosphere

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 7 Wednesday 15 November continued

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 2.15–2.30pm M.11 Earth system climate reanalyses Patrick Laloyaux 4.15–4.30pm E.04 Mean age of stratospheric air since Simon Chabrillat (BIRA- at ECMWF (ECMWF) 1985: large disagreements between five IASB) modern reanalyses 2.30–5.15pm Section 4 – Evaluation and intercomparisons of reanalyses 4.30–4.45pm E.05 Assessment of Hadley Cell Dynamics Sneha Susan Mathew Chairs: Franco Desiato (ISPRA), Masatomo in JRA55 Reanalysis Data (Space Physics Fujiwara (Hokkaido University), Sonia Laboratory India) Seneviratne (ETH), Adrian Simmons (ECMWF) 4.45–5pm E.06 Towards consistent diagnostics Michael Mayer 2.30–3pm E.01 (Invited Talk) Results from the SPARC Masatomo Fujiwara of the coupled atmosphere and ocean (University of Vienna) Reanalysis Intercomparison Project (S-RIP) (Hokkaido University) energy budgets during 2013-2017 5–5.15pm E.07 Land surface precipitation and Rolf Reichle (NASA/ 3–3.15pm E.02 Assessment of upper tropospheric Sean Davis (NOAA hydrology in MERRA-2 GSFC) and stratospheric water vapor and ozone ESRL) in reanalyses as part of S-RIP 5.15-6pm Invited Keynote Gil Compo K.3 Future Earth-System reanalyses: (CU/CIRES & NOAA) 3.15–3.30pm E.03 Preliminary assessment of the ERA5 Rossana Dragani An atmospheric perspective ozone reanalyses (ECMWF) 3.30– 4.15pm Coffee break

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 8 Thursday 16 November

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 9–11.45am Section 4 (continued) – Evaluation and 11.15 –11.30am E.14 Do reanalyses capture long-term Prashant Sardeshmukh intercomparisons of reanalyses changes in extreme weather statistics? (CU/CIRES & NOAA) Chairs: Franco Desiato (ISPRA), Masatomo 11.30 –11.45am E.15 AFES-LETKF data assimilation system Akira Yamazaki Fujiwara (Hokkaido University), Sonia for an experimental atmospheric global (JAMSTEC) Seneviratne (ETH), Adrian Simmons (ECMWF) ensemble reanalysis 9–9.15am E.08 Quantifying spatio-temporal variations Clemens Schwingshackl 11.45am–12.15pm Section 5 – Applications of reanalyses of soil moisture control on surface energy (ETH) Chairs: Andrea Kaiser-Weiss (DWD), balance and near- surface air temperature Carolin Richter (WMO), Michel Rixen (WCRP), 9.15–9.30am E.09 Assessment of precipitation in the Elke Rustemeier (DWD) Jean-Noël Thépaut (C3S-ECMWF) CERA-20C and ERA-20C reanalyses by 11.45am–12.15pm Invited Talk Karina Von means of precipitation gauge observations A.01 Insights into the role Schuckmann (Mercator) 9.30-9.45am E.10 Improved SST-precipitation relationships Xiangbo Feng of the oceans in the Earth energy budget in the CERA-20C coupled climate reanalysis (University of Reading) from ocean reanalysis 9.45–10am E.11 An intercomparison of the Arctic sea ice Matthieu Chevallier 12.15–12.30pm Introduction to Poster Session # 3 cover in global ocean-sea ice reanalyses from (Météo- France) 12.30–2pm Lunch and Poster Session # 3 the project ORA-IP Posters on Applications of reanalyses 10–10.15am E.12 Uncertainty in Reanalysis over Europe Peter Jermey (Met with authors standing in front of poster Office) from 1pm to 2pm 10.15–10.30am E.13 800+ site validation of Reanalysis & Gil Lizcano (Vortex) downscaled wind conditions time series 10.30–11.15am Coffee break

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 9 Thursday 16 November continued

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 2–5.15pm Section 5 (continued) – 3.15–3.30pm A.07 Intercomparison of the near-surface Verónica Torralba Applications of reanalyses wind speed trends in three reanalyses (Barcelona Chairs: Andrea Kaiser-Weiss (DWD), Carolin Supercomputing Center) Richter (WMO), Michel Rixen (WCRP), Jean- Noël Thépaut (C3S-ECMWF) 3.30– 4.15pm Coffee break 2–2.15pm A.02 Reanalyses’ use in operational Roberto Buizza 4.15–4.30pm A.08 On requirements for the application Frank Kaspar (DWD) weather forecasting (ECMWF) of reanalyses in the context of climate monitoring and energy applications 2.15–2.30pm A.03 Stratospheric intrusion-influenced ozone Katherine Emma in Germany air quality exceedances investigated in the Knowland (NASA NASA MERRA-2 Reanalysis GMAO) 4.30–4.45pm A.09 On the use of the 50-year high- Patrick Le Moigne resolution UERRA re-analysis for a hydro- (Météo- France) 2.30–2.45pm A.04 Classification of Meteorological Allison Collow meteorological application over Europe Influences Surrounding Extreme Precipitation (NASA/GSFC) Events in the United States using the 4.45–5pm A.10 Development of long-term hydro- Rémy Bonnet MERRA-2 Reanalysis meteorological reconstructions over France (CERFACS) based on large scale atmospheric reanalyses 2.45–3pm A.05 Role of Southern Annular Mode on Asian Amita Prabhu (Indian to study the multi-decadal variability of Monsoon: Mechanisms through NCEP-NCAR Institute of Tropical French river flows Reanalysis Meteorology) 5–5.15pm A.11 From data mining to information Matteo De Felice (ENEA) 3–3.15pm A.06 Arctic warming from calculations on Aleksandra Urazgildeeva extraction: using ERA-INTERIM reanalysis to base ERA- Interim (AARI) model hydro-power production in Europe 5.15–6pm Invited Keynote Magdalena Alonso- K.4 Future Earth-System reanalyses: Balmaseda (ECMWF) An ocean perspective

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 10 Friday 17 November

Time slot Title Speaker (affiliation) Time slot Title Speaker (affiliation) 9–10.30am Section 5 (continued) – Applications 10.45 –11am S.02 Summary and key message Stefan Brönnimann of reanalyses from Section 2 (University of Bern), Chairs: Andrea Kaiser-Weiss (DWD), Carolin Nick Rayner (Met Office) Richter (WMO), Michel Rixen (WCRP), Jean- 11.00 –11.15am S.03 Summary and key message Magdalena Alonso- Noël Thépaut (C3S-ECMWF) from Section 3 Balmaseda (ECMWF), 9–9.15am A.12 Mediterranean Sea circulation Gianmaria Sannino Gil Compo (CU/CIRES & in high-resolution hindcast simulations (ENEA) NOAA), Dick Dee (C3S), and reanalyses Zhiquan Liu (NCAR & CMA) 9.15–9.30am A.13 A three-dimensional characterization Andrea Cipollone of eddy activities in a global ocean eddy- (CMCC) 11.15 –11.30am S.04 Summary and key message Franco Desiato (ISPRA), permitting reanalysis from Section 4 Masatomo Fujiwara (Hokkaido University), 9.30–9.45am A.14 Downscaling ERA5 reanalysis data for Carlo Brandini (CNR) Sonia Seneviratne coastal climate applications and evaluation (ETH), Adrian Simmons of uncertainty of coastal data (ECMWF) 9.45–10am A.15 A roadmap to Earth surface kilometre- Gianpaolo Balsamo 11.30 –11.45am S.05 Summary and key message Andrea Kaiser-Weiss scale simulations (ECMWF) from Section 5 (DWD), Carolin Richter 10–10.30am Coffee break (WMO), Michel Rixen (WCRP), Jean-Noël 10.30am– Summary and key messages from Thépaut (C3S-ECMWF) 12.30pm the 5 Sections and Plenary discussion 11.45am– Plenary discussion Michel Rixen (WMO/ 10.30–10.45am S.01 Summary and key message Michael Bosilovich 12.30pm WCRP), Roberto Buizza from Section 1 (NASA GMAO), Shinya (ECMWF) and Paul Poli Kobayashi (JMA), (Météo-France) Simona Masina (CMCC) 12.30-1pm Closure

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 11 Talks

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 12 retrospectively to surface and upper-air Keynotes Future Earth-System reanalyses: observations from the 1940s to the 1970s An atmospheric perspective and then including satellite observations to today. Author Gilbert Compo Reanalysis: Past, Present Affiliation University of Colorado/ In the 21st century, these “full-input” and Future CIRES & NOAA/ESRL/ reanalyses have advanced, and additional work has also generated Author Adrian Simmons Physical Sciences Division reanalysis datasets using advanced Affiliation ECMWF data assimilation systems and only Co-authors surface observations that extend The development of the observing GP Compo (University of Colorado at reanalysis back to the 1850s. These system for weather and climate, and Boulder, CIRES & NOAA Earth System accomplishments, though successful, the origins, evolution, achievements Research Laboratory, Physical Sciences have still left several areas of great and applications of reanalysis will be Division), JS Whitaker (NOAA Earth societal relevance in need of attention. reviewed. Future directions will be System Research Laboratory, Physical Among these, for the complete period of indicated. Emphasis will be placed on Sciences Division), PD Sardeshmukh the instrumental record extending back some of the challenges that have been (University of Colorado at Boulder, CIRES to the 18th century, future reanalyses of encountered in undertaking reanalysis, & NOAA Earth System Research the atmosphere need to achieve success presenting examples of the significant Laboratory, Physical Sciences Division), in providing reliable representation of progress that has been made and LC Slivinski (University of Colorado at the climate and variability of extreme discussing issues, longer-standing and Boulder, CIRES & NOAA Earth System weather statistics; high impact weather emerging, that remain to be satisfactorily Research Laboratory, Physical Sciences phenomena, such as tropical cyclones; addressed. Broader institutional matters, Division), P Brohan (Met Office Hadley and atmospheric trace gases and including international cooperation, will Centre), and R Allan (Met Office Hadley aerosols. also be discussed. Centre) All of these should be determined from Since 1819, when Brandes followed up the surface of the earth to the boundaries Future Earth-System reanalyses: on his original 1816 proposal for making of space. Thoughts on the current status A land perspective a “weather map” by retrospectively and possibilities for achieving these goals analyzing the surface pressure over Author Sonia Seneviratne for datasets spanning the continually- parts of Europe for every day of the Affiliation ETH Zürich evolving instrumental record back to year 1783, atmospheric “reanalysis” Brandeis’s original reanalysis maps will [Content required] has been a staple of weather and be discussed. climate science. In the 20th century, massive subjective reanalysis efforts of the early century were followed by the modern achievement of consistent data assimilation systems from numerical weather prediction being applied

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 13 Keynotes

In particular, reanalyses are now key Future of Earth System for the understanding of the energy, Reanalyses: An Ocean water and carbon cycles. Consistent Perspective century-long reanalyses able to exploit the sparse observations in the distant Author Magdalena Alonso past as well as the wealth of current Balmaseda high-resolution observations are also Affiliation ECMWF needed to initialize seasonal and decadal Co-authors predictions. These primary challenges in M.A. Balmaseda our efforts to predict, mitigate and adapt to climate change. Coupled earth system Ocean reanalyses capabilities have gone reanalyses offer a path to tackle these a long way during the last decade, fuelled critical questions. by advances in the ocean observing They should provide traceable inventories system, model and data assimilation of transports, sources and sinks, methods, availability atmospheric involved in the primary climate cycles, reanalyses, as well as concerted and, in principle, they are powerful tools community efforts in production and to optimise the use of observations. inter-comparison. But this is a major undertaking, paved Nowadays ocean reanalyses are with new challenges, which will require produced routinely by a number of major development in assimilation institutions to monitor the ocean climate methodology, coupled modelling and and to initialize weather and climate activities in data rescue. predictions. As the field advances, so are expectations and the potential applications. The inherent quest for increasing quality (longer time span, increased resolution and temporal consistency, uncertainty estimates) goes hand in hand with new scientific questions and a wider range of demands.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 14 1-deg. resolution prescribed over 55 (to be completed early 2018) covers, like Section 1 – Status years. The other is an additional product State-of-the-art Atmospheric ERA-Interim, the satellite period from and plans of (JRA-55CHS) with MGDSST data with Reanalysis at ECMWF 1979 onwards. a 25-km resolution only over 28 recent Monthly updates are provided and reanalysis products years. Author Hans Hersbach Affiliation ECMWF consolidated in an official release about The comparison reveals substantial two to three months behind real time, On the Significance of Using differences in midlatitude atmospheric Co-authors although preliminary data products High-Resolution Sea-Surface processes around the western boundary Hans Hersbach (ECMWF), Paul Berrisford will be made available within a week Temperature in Atmospheric currents and associated SST fronts. (ECMWF), Gionata Biavati (ECMWF), Per of production. In a second phase Reanalysis Production As a typical example, atmospheric Dahlgren (ECMWF), Dick Dee (ECMWF), (production to start in 2018) a pre- response to variability of the Kuroshio Rossana Dragani (ECMWF), Manuel extension back to 1950 is planned. ERA5 Author Hisashi Nakamura Extension (KE) is examined. As in satellite Fuentes (ECMWF), Andras Horanyi will provide a large number of essential Affiliation University of Tokyo observations, enhancement of cloudiness (ECMWF), Joaquin Munoz-Sabater climate variables within the C3S Climate (ECMWF), Carole Peubey (ECMWF), Co-authors and precipitation in the oceanic frontal Data Store (CDS). zone east of Japan during the unstable Raluca Radu (ECMWF), Iryna Rozum H. Nakamura (Univ. Tokyo), R. Masunaga Compared to ERA-Interim, ERA5 regime of KE relative to its stable regime (ECMWF), Dinand Schepers (ECMWF), (Univ. Tokyo), H. Kamahori (MRI-JMA), incorporates many important innovations is represented well in JRA-55CHS but not Adrian Simmons (ECMWF), Cornel Soci C. Kobayashi (MRI-JMA), S. Okajima that safeguard the provision of state- in JRA-55C product. The enhancement, (ECMWF), Jean-Noël Thépaut (ECMWF) (Univ. Tokyo), T. Miyasaka (Univ. Tokyo), of-the-art climate reanalysis. ERA5 is which results from augmented heat/ and Sebastien Villaume (ECMWF) K. Nishii (Mie Univ.) based on a recent version of the ECMWF moisture release from the warmer ocean At the European Centre for Medium- Recent studies have identified distinct Integrated Forecast Model which with more active warm-core eddies, Range Weather Forecasts (ECMWF), impacts of the warm western boundary includes numerous improvements to the comes to be better represented in reanalysis is a key contribution to the currents, such as the Gulf Stream and 4D-Var assimilation method as well as ERA-Interim after 2001, when the SST Copernicus Climate Change Service Kuroshio, and associated midlatitude the coupled atmosphere, ocean waves resolution was improved. (C3S) that is implemented at ECMWF on frontal zones on the overlying and land model. behalf of the European Commission. This atmosphere, including boundary-layer This oceanic thermal forcing onto the presentation provides an overview of the wind/thermal structure, vertical motion atmosphere is manifested as positive latest ECMWF atmospheric reanalysis and cloud-precipitation systems. correlation in anomalies between SST and heat/moisture release, which is ERA5, which is currently in production Their representation in reanalysis should represented only in the high-resolution and will replace the widely used ERA- be sensitive to the resolution of SST MGDSST but not in COBE SST. As Interim reanalysis. data prescribed at the lower boundary another example, stormtrack response to ERA5 is the fifth generation of ECMWF of a forecast model, and the sensitivity meridional displacement of the Oyashio atmospheric reanalyses of the global is assessed through comparison of two front is examined. Again, the positive climate, which was pioneered with the products of a new Japanese reanalysis correlation between anomalous SST and FGGE reanalyses produced in the 1980s, (JRA-55). One is JRA-55C, in which heat/moisture release is much stronger in followed by ERA-15, ERA-40 and most observed data have been assimilated in a JRA-55CHS, and so is the enhancement recently ERA-Interim. Production is forecast system with horizontal resolution of convective precipitation over warm taking place in two phases. A first phase of ~60km and the COBE SST data with SST anomalies.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 15 Section 1

key research priorities. This presentation product at an enhanced resolution. step toward GMAO’s longer term goal of Earth System Data Assimilation will discuss various activities of the The presentation will conclude with an developing an integrated Earth system and Reanalysis Efforts MAPP Program to advance Earth system outlook on plans for the next ECMWF analysis (IESA) capability that will couple Supported by the NOAA Climate DA and reanalysis. C3S reanalysis, ERA6. assimilation systems for the atmosphere, ocean, land and chemistry. Program Office’s MAPP Program Radiative forcing data are used that represent the observed evolution of The GMAO strategy is to progress Author Annarita Mariotti Status and plans for reanalysis greenhouse gases, volcanic eruptions, incrementally toward an IESA through an Affiliation NOAA Climate Program at the NASA Global Modeling ozone and aerosols, and consistent and Assimilation Office evolving combination of coupled systems Office – MAPP Program boundary conditions are used for sea- and offline component reanalyses driven Co-authors surface temperature and sea ice. A Author Ron Gelaro by, for example, MERRA-2 atmospheric A. Mariotti, H. Archambault, and D. Barrie number of reprocessed data records Affiliation NASA forcing. Most recently, the GMAO (NOAA Climate Program Office – are ingested as well as several data has implemented a weakly coupled Co-authors Modeling, Analysis, Predictions, and sets that have never before been used assimilation scheme for analyzing ocean R. Gelaro(1), S. Pawson(1), A. da Silva(1), Projections) Program in reanalysis. ERA5 is able to assimilate skin temperature within the existing W. Putman(1), W. McCarty(1), A. El data from the latest instruments. atmospheric analysis. Akkraoui(2,1), S. Akella(2,1)(1) NASA The Modeling, Analysis, Predictions, Observation bias correction schemes Goddard Space Flight Center, Greenbelt, The scheme uses background fields from and Projections (MAPP) Program is a have been extended and improved. competitive grants program in the NOAA MD, USA(2) Science Systems and a near-surface ocean diurnal layer model Office of Oceanic and Atmospheric ERA5 is produced at considerably Applications, Inc., Lanham, MD, USA to assimilate surface-sensitive radiances Research Climate Program Office that higher resolution than ERA-interim: plus in-situ observations along with all Reanalysis plays a critical role in GMAO’s supports data assimilation (DA) and new hourly analysis fields are available at a other observations in the atmospheric goal to enhance NASA’s program of techniques for reanalysis as part of its horizontal resolution of 31 km on 137 assimilation system. In addition, MERRA- Earth observations, providing vital core mission. levels in the vertical. Data products 2-driven simulations of the ocean (plus include information about uncertainties data sets for climate research and the sea ice) and atmospheric chemistry (for Recently, the MAPP Program funded generated by a lower-resolution (62 km) development of future missions. As the the EOS period) are currently underway, a set of projects to evaluate and 10-member 4D-Var ensemble. A number breadth of NASA’s observations expands as is the development of a coupled improve aspects of NOAA’s reanalysis of new parameters, such as 100-metre to include multiple components of the atmosphere-ocean assimilation system. for climate monitoring and prediction, wind speed and direction, are available Earth system, so does the need to This talk will describe the status of these with the investigators leading these as part of the output, based on user assimilate observations from currently ongoing efforts and the planned steps projects constituting the MAPP Climate requirements and identified gaps in uncoupled components of the system in toward an IESA capability for climate Reanalysis Task Force. previous reanalysis productions. a more physically consistent manner. research. Now, as NOAA moves toward a unified A database containing all ingested GMAO’s most recent reanalysis of the modeling and DA framework to support observations, together with detailed satellite era, MERRA-2, has completed monitoring and prediction of the Earth information about how they are used, the period 1980-present, and is now system across timescales, the MAPP is available to users. In addition, a running as a continuing global climate Program has identified coupled DA and dedicated ERA5 land component analysis with two- to three-week latency. improved or new DA-based monitoring will deliver a land-surface reanalysis MERRA-2 assimilates meteorological products for the ocean, cryosphere, land and aerosol observations as a weakly surface, and atmospheric composition as coupled assimilation system as a first

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 16 Section 1

These improvements have made JRA-55 Additionally, the algorithms needed to Reanalysis at the Japan products considerably better than JRA- Improvements in the Twentieth represent sampling and model error, Meteorological Agency 25 products; the temporal consistency Century Reanalysis Version 3 covariance inflation and localization, have of temperature analysis is, in particular, been updated in version 3 and have led Author Shinya Kobayashi improved considerably over that of Author Laura Slivinski to improved quantification of uncertainty. Affiliation Japan Meteorological previous reanalyses. For variables and Affiliation Univ. of Colorado’s Results with the previous system (version Agency regions in which the forecast model has Cooperative Institute for 2c) show that the uncertainty tends to be Co-authors large biases, however, there still remain Research in too low in data-rich regions, and too high Shinya Kobayashi (Japan Meteorological large uncertainties in the represented Environmental Sciences in data-sparse regions; these effects are Agency) trends due to the fact that degree of Co-authors generally improved upon in the version constraint on the model biases varies LC Slivinski (CIRES/NOAA), GP Compo 3 system. The new version also includes One of the major issues in reanalysis with changes in observing systems. The (CIRES/NOAA), JS Whitaker (NOAA), a bias correction to marine observations is temporal consistency extending upper and middle tropospheric humidity, PD Sardeshmukh (CIRES/NOAA) prior to 1870, which is calculated offline over decadal and longer time scales. for example, shows spurious trends and considers the particular ship from Improving temporal consistency in due to the fact that a dry bias tends The international Twentieth Century which the observation came. Results of future reanalyses is essential for to diminish slightly as the number of Reanalysis (20CR) project led by testing this new bias correction and other improving operational climate services observations from satellite water vapour NOAA and CIRES provides global, improvements will be discussed. and advancement in climate research. channels increases. subdaily weather estimates throughout For this end, the Japan Meteorological the troposphere stretching back over Agency (JMA) conducted the Japanese To facilitate investigations on the 150 years. It assimilates only surface CMA Global Reanalysis: 55-year Reanalysis (JRA-55) for the credibility of low-frequency variability pressure observations into the NCEP Status and Plan period from 1958 onward. JRA-55 has and trends represented in JRA-55, the Global Forecast System constrained by Author Zhiquan Liu been produced with the TL319 version JMA Meteorological Research Institute sea surface temperatures and sea ice of JMA’s operational data assimilation has produced a reanalysis assimilating concentration. In addition, the ensemble Affiliation NCAR system as of December 2009, and its conventional observations only, called Kalman filter data assimilation method Co-authors production has been continued on a JRA-55C, and an AMIP-type simulation, used in 20CR provides quantification of Zhiquan Liu (NCAR &CMA), Lipeng Jiang, near-real-time basis. called JRA-55AMIP. uncertainty around these estimates via Tao Zhang, Jie Liao, Chunxiang Shi, the ensemble spread. Zijiang Zhou, Lijuan Cao, Kaixi Hu, Hui This system features numerous These are produced with the same Jiang, Xiao Liang, Jingwei Liu, Dong Si, improvements made since the previous numerical weather prediction system The new version 3 system incorporates Chenghu Sun, Mingyan Wang, Shuang Japanese reanalysis (JRA-25). JRA- as used for JRA-55, and they are made several improvements over the previous Yao, Yizhou Yin, Zhishen Zhang, Bin 55 also incorporates several newly available together with JRA-55 products data set, version 2c, including a higher- Zhao (CMA) available observational datasets as the JRA-55 family. JMA is currently resolution model, a larger ensemble, and preparing the next reanalysis, called the produced as a result of ongoing efforts more observations. Version 3 uses a more CMA started a global reanalysis effort Japanese Reanalysis for Three Quarters to improve quality of past observations, sophisticated data assimilation algorithm from early 2014, which aims to producing of a Century (JRA-3Q), with the aim of including homogenization of radiosonde than version 2c, leading to a reduction of 40 years (1979-2018) atmospheric and producing a more improved reanalysis temperature observations and spurious trends in 6-hour precipitation land reanalysis products (CRA-40) and contributing to climate services and reprocessing of satellite data at major forecasts from version 2c. by 2020 and then continuing it as the climate research. meteorological satellite centres. operational climate analysis system for

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 17 Section 1 climate monitoring and service purposes. through the development of operational The original plan was to produce CRA-40 The CMEMS global and regional Ocean Monitoring Indicators (OMIs), and The CMCC Global Ocean by upgrading CMA’s operational NWP ocean reanalyses: towards a related error bars. Reanalysis System (C-GLORS): system of 2014. However, experimental consistent set of high resolution These developments must rely on a multi-purpose family of eddy- tests in 2015 showed that the operational ocean reanalyses for operational continuous and high quality reanalyses permitting ocean reanalyses system could not produce reanalysis and reprocessing time series, which go products with desired quality. oceanography users and ocean Author Andrea Storto state monitoring up to real time. Both C3S and CMEMS After further testing and comparison, reanalyses are used. Affiliation CMCC it is decided in late 2016 that this first Author Marie Drevillon Co-authors The CMEMS reanalyses are different and generation CMA reanalysis will move Affiliation Mercator Ocean A Storto (CMCC), S Masina (CMCC complementary to the C3S reanalyses, to NOAA’s GFS/GSI-based model and and INGV), A Cipollone (CMCC), D Iovino Co-authors which first objective is to achieve the data assimilation system for atmospheric (CMCC) M. Drévillon (Mercator Ocean), K. von accurate description of climate variability. component and recently released Schuckmann(Mercator Ocean) CMEMS reanalyses aim at a seamless NASA’s Land Information System (LIS) An eddy-permitting global ocean P.-Y.Le Traon(Mercator Ocean, Ifremer) connection with CMEMS real time for land component. Thus far, more reanalysis system is under continuous analyses and forecast, thus CMEMS than 100 TB historical conventional and The Copernicus Marine Environment development at CMCC. The system is regional reanalyses particularly benefit satellite observations were collected. Monitoring Service CMEMS aims called C-GLORS (CMCC Global ocean from both higher resolution and specific Some careful data evaluation and quality to deliver generic and reliable reanalysis system) and implements a regional tunings. control were performed with emphasis information, derived from space and 3DVAR data assimilation scheme to on better usage of data from Chinese in-situ observations and from models Particular efforts are put on assimilate hydrographic profiles and observing networks. – including forecasts, analyses and the processing of sea ice and altimetry data, a nudging scheme for reanalyses – on the physical and biogeochemistry components. CMEMS assimilating sea-surface temperature and Currently, a 10-year (2007/01-2016/12) biogeochemical state over the global assures the collections of “best quality” sea-ice concentration data from satellite, Interim reanalysis is in production with ocean and the European regional input data and maximal use of multiple and a large-scale bias correction GFS and GSI-3DVAR at T574 spectral seas. One of the main requirements observation systems, and, on the long scheme. resolution and shall be completed this from operational oceanography users term, aims at a fully consistent approach September. Preliminary evaluation of this The ocean model component is NEMO is to have long time series of data across global and regional reanalyses, CRA-Interim product and future plan will at 1/4 degree resolution coupled with the as a reference statistical and quality organizing their interoperability, their be presented. LIM2 sea-ice thermo-dynamical and framework. inter-dependencies, and joint operations dynamical model. Here we present an closer to real time (a few months only) Among those users, environmental historical perspective on the CMCC with a systematic yearly update. agencies also require ocean state and ocean reanalysis activities during the marine environment monitoring, which is last decade, focusing on the main achieved through the annual release of achievements reached, from past the CMEMS Ocean State Report (OSR) coarse-resolution retrospective analyses to monitor and describe ocean variability to the recent real-time ensemble ocean and change from the past to present; and reanalyses used for initializing the CMCC seasonal prediction system, to the latest release included in the

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 18 Section 1

Copernicus Marine Service catalogue CERA-SAT is a pilot reanalysis of the for a comprehensive integration of the and the participation to international satellite-era -funded by the ERA-CLIM2 Improving the representation of regional climate of the Arctic for 2000- inter-comparison activities. Applications FP7 project- aimed at progressing the the Greater Arctic with ASRv2 2012. of the reanalysis and process-oriented Earth System approach. It comprises ASRv2 surface and pressure level analyses will be given as well, looking for coupled assimilation of atmosphere, Author David Bromwich products are available at 3-hourly and instance at the effect of data assimilation ocean, waves, sea ice and land surface Affiliation Ohio State University monthly-mean timescales at NCAR. on polar regions transports and eddy observations provided by the modern- Co-authors ASRv2 has new features including higher population, along with a detailed quality day observing system. D.H. Bromwich1, A.B. Wilson1, L-S Bai1 resolution depiction in space (15 km assessment. Finally, future directions At its heart sits a pioneering coupled (Ohio State University 1), Z. Liu2, M. horizontal resolution), updated model including feasibility of updating the ocean-atmosphere data assimilation Barlage2, C-F Shih2, (NCAR 2), S physics including sub-grid scale cloud system to hybrid ensemble/variational system (CERA) which couples a 3D-Var Maldanado1, K.M. Hines1, S-H Wang1, fraction interaction with radiation, and a four-dimensional data assimilation and ocean assimilation system (NEMOVAR) to J. Woollen 3 (NCEP 3), B. Kuo2, H-C dual outer loop routine for more accurate plans for eddy-resolving reanalyses will the ECMWF Integrated Forecast System Lin2, T-K Wee2, M.C. Serreze4 data assimilation. be given. (IFS) 4D-Var atmospheric assimilation (University of Colorado-Boulder 4), and An evaluation of ASRv2 yields a system at the outer loop level. J.E. Walsh5 (University of Alaska- Fairbanks 5). superior reproduction of near-surface CERA SAT: coupled reanalysis in Weakly coupled to this is a land surface and tropospheric variables. Forecast the satellite-era analysis based on a combination of The Arctic is in the midst of rapid precipitation and downward radiative environmental changes, spurred Author Dinand Schepers optimal interpolation (OI) and simplified fluxes demonstrate significant Extended Kalman Filter (EKF). CERA- by amplified effects due to human improvement over ASRv1. The high- European Centre for Affiliation SAT – projected to cover 8 years starting activities and natural variability. Global resolution topography and land surface, Medium-Range Weather in 2008- is produced using a 10-member atmospheric reanalyses that merge a including weekly-updated vegetation Forecasts (ECMWF) Ensemble of Data Assimilations (EDA) wide variety of surface, atmospheric and and realistic sea-ice fraction, thickness, Co-authors system coupling an atmosphere at 60 satellite remote sensing data into gridded and snow cover depth resolve fine-scale Dinand Schepers (ECMWF), Eric de kilometre resolution on 137 vertical levels analyses have long been relied upon to processes such as topographically- Boisseson (ECMWF), Roberto Buizza with an eddy-permitting quarter degree investigate Arctic climate change and forced winds. (ECMWF), Per Dahlgren (ECMWF), Dick ocean model. accompanying variability during recent Dee (ECMWF), Yuki Kosaka (ECMWF, decades. However, changing observing Thus, ASRv2 is particularly suitable for JMA), Patrick Laloyaux (ECMWF) In this presentation we present the systems create issues for climate change detailed investigations of near-surface CERA-SAT coupled assimilation investigations. characteristics during the period of The European Centre for Medium-Range approach, features of the reanalysis data rapid Arctic change; and therefore, Weather Forecasts (ECMWF) is a key set and a preliminary assessment of This presentation introduces version 2 of complements the multi-decadal player in the production of reanalyses benefits of coupled data assimilation in the Arctic System Reanalysis (ASRv2), a perspective of the global reanalyses. for climate monitoring as well as the data-rich satellite-era. multi-agency, university-led retrospective research. In line with the Earth system analysis (reanalysis) of the Greater Arctic approach defined in the current ten (poleward of 45°N). ASRv2 uses blends year strategy, ECMWF has developed a of the polar-optimized version of the coupled assimilation system for ingesting Weather Research and Forecasting (Polar observations of ocean and atmosphere in WRF) model and WRF three-dimensional a coupled ocean-atmosphere model. variational data assimilated observations

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 19 Section 1

warmer months of the year, owing to The temporal resolution of the output under summer 2017. The goal of the BARRA: a high-resolution the Australian climate, vast areas of analysis fields for both the regional service is to provide a regional reanalysis Atmospheric Reanalysis for dry grass and high oil content in native and higher-resolution subdomains are (RRA) for the atmosphere over Europe, 1990-2016 over Australia plants. More broadly, benefits from the generally one hour, with many fields which will be updated in near real-time. reanalysis are expected for land-use and such as surface winds and temperatures In this presentation, we will give an Author Chun-Hsu Su water management, primary industries, available every 10 minutes. Other output overview on what can be expected from Affiliation Bureau of Meteorology and the health, energy, defence, and variables include moisture, pressure, the service within the next years. In the minerals sectors. cloud cover, precipitation, evaporation, Co-authors first phase, PRECISE products will be energy fluxes, and soil water. Here C.-H. Su (Bureau of Meteorology, To fully realise benefits, researchers, based on the model system developed we report on the implementation of Docklands, Australia), N. Eizenberg governmental agencies and industry in the pre-operational project UERRA BARRA and preliminary evaluations, and (Bureau of Meteorology, Docklands, are collaborating to add value to the (there will be separate presentations on describe a range of its applications of Australia), G. Kociuba (Bureau of reanalysis data. BARRA is a 12-km UERRA, e.g. Ridal et al. and Undén et. immediate interest to meteorologists, Meteorology, Docklands, Australia), regional-scale reanalysis, nested within al.). While UERRA produced data sets for fire and landscape managers, and other P. Steinle (Bureau of Meteorology, the required boundary and/or initial the period 1961-2015, PRECISE will fill members of the emergency management Docklands, Australia), Dörte Jakob conditions provided by the coarse-scale the gap throughout 2016 and early 2017. community. This includes the use of (Bureau of Meteorology, Docklands, ERA-Interim reanalysis, Operational SST reanalysis to create tailored fire weather This will be followed by monthly updates Australia), Paul Fox-Hughes (Bureau and Sea Ice Analysis, and the Bureau’s products for the fire agencies. in near real-time. Hence, PRECISE will of Meteorology, Hobart, Australia) offline soil moisture reanalysis. We use offer a consistent RRA from 1961 to near an unchanging atmospheric modelling The Australian Bureau of Meteorology real time. The onset of the operational suite based on the UERRA (Uncertainties has commenced a project to produce PRECISE – Production of a monthly updates can be expected in in Ensembles of Regional ReAnalysis) a high-resolution 1990–2016 reanalysis regional Reanalysis for Europe early 2018. All data will be saved with system used at the UK Met Office and covering the Australian continent and within the Copernicus climate hourly resolution and will be freely the more recent version of the Unified the surrounding regions, including New available via the Copernicus Data Store Model used in the Bureau’s weather change Services Zealand and parts of southeast Asia. (CDS). The production system will be prediction systems. This reanalysis is in the following referred Author Semjon Schimanke discussed in the presentation. to as BARRA (Bureau of Meteorology A 4D deterministic variational data Affiliation SMHI Here, we will focus on the challenges Atmospheric high-resolution Regional assimilation scheme is used to optimally Co-authors of producing the RRA operational in Reanalysis for Australia). Production runs combine model physics with multiple S. Schimanke (SMHI), P. Undén (SMHI), near real-time. In the second phase, it is commenced in March 2017. observations from aircraft, sondes, M. Ridal (SMHI), L. Berggren (SMHI), planned to switch to a more advanced surface observations and satellites. system that will be developed while the Jointly funded by fire and emergency P. Le Moigne (Météo-France), E. Bazile BARRA also consists of multiple operational production of the RRA carries service agencies in New South Wales, (Météo-France), H. Schyberg (MET convective-scale (1.5 km) downscaling on during phase one. Tasmania, Western Australia and South Norway), R. Randriamampianina analyses driven by the 12 km system, for Australia and with major co-contribution (MET Norway) The new PRECISE reanalysis system supporting fire services. Downscaling by the Bureau of Meteorology, will be built on but extending from can be performed anywhere in the PRECISE (Production of a regional this project supports high-quality the UERRA system in several ways: regional domain. Reanalysis for Europe within the assessments of risk and likelihood of Copernicus climate change SErvices) is a The horizontal resolution of the data wildfires, in Australia known as bushfires. Copernicus service that will be launched assimilation system will be enhanced These are frequent events during the

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 20 Section 1 from 11 km to 5.5 km and also the and land-use induced changes in vertical resolution will be increased from Reanalyses of Atmospheric biomassburning as well as trends in 65 to about 90 levels. The top of the Composition at ECMWF: anthropogenic emissions. model will be raised to allow assimilation from MACC to CAMS We will also showresults from the of satellite radiances. Moreover, the latest CAMS reanalysis which is being number of layers in the boundary layer Author Antje Inness produced at themoment. Both reanalyses will increase. Affiliation ECMWF are based on a fully integrated approach The MESCAN surface analysis of Co-authors combining both meteorology and temperature and humidity will be A Inness (ECMWF), J Flemming atmospheric composition in one data integrated in the production reanalysis (ECMWF), R Engelen (ECMWF), M Ades assimilation system with the new CAMS since no downscaling will be necessary. (ECMWF), A Agusti-Panareda (ECMWF), reanalysis being more comprehensive, New input data sets will be tried Z Kipling (ECMWF), S Massart (ECMWF), including many chemical species, and integrated and a number of new M Parrington (ECMWF), M Suttie aerosols and greenhouse gases. observation types or instruments will (ECMWF), VH Peuch (ECMWF) The new reanalysis also exploits various be tested. The lateral boundary will be In addition to meteorological reanalyses, interactions, such as the interaction forced by the global ERA5 RA. reanalysis data sets ofatmospheric between aerosol and radiation and the The onset of the production with the new composition have been emerging in interaction between the meteorology and system ushers the second phase of the the last decade. ECMWF hasproduced the land biosphere model for CO2. service in, which is scheduled for 2019. several reanalyses of atmospheric The RRA dataset will start in the early composition (e.g. reactivegases, aerosols 1980’s and will be updated operational in and greenhouse gases) under the EU near real-time. Details of the advanced funded GEMS and MACCprojects and system as well as the time schedule will the Copernicus Atmosphere Monitoring be discussed. Service (CAMS). These reanalyses use data assimilation to combine satellite retrievals of atmospheric composition with state of the art atmospheric composition models to produce long, consistent datasets. In this talk we will show results from the recent CAMS interimreanalysis which covers the period from 2003 to the present day andprovides analysis fields

for CO, O3 and AOD. This reanalysis can, forexample, be used to evaluate recent trends (2003-2016) in CO, which aremainly caused by El-Nino (2015)

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 21 Reanalysis) ongoing project (2014- have also been ensured. In this case, Section 2 – Data rescue activities to support 2017) focus is on producing ensembles the DARE effort includes meteorological Observations for reanalysis and climate services: of regional reanalyses for several stations in western and eastern reanalyses the EU-funded UERRA and decades and estimating the associated Mediterranean, North Africa, the Middle EURO4M projects approaches uncertainties in the derived data sets. East, the Balkans, central and eastern Both projects have a core component Europe and Scandinavia mostly for the Preparing Observations for and outcomes of data rescue (DARE) of meteorological post-1950 period. observations, while ensuring DARE Reanalysis Author Manola Brunet The targeted variables have been air coordination to avoid duplicating efforts. Author Nick Rayner Affiliation Universitat Rovira i Virgili, pressure, air temperature, dew-point, Tarragona In this contribution, we will provide relative humidity, cloud cover and wind Affiliation Met Office Hadley Centre Co-authors detailed information about strategies, speed and wind direction (precipitation, Co-authors M. Brunet1, 2, P. Jones2, A. Gilabert1, approaches and outcomes of the DARE snow-depth, fresh snow) at the hourly N.A. Rayner (Met Office Hadley Centre) P. Unde n 3, L. Ashcroft1, J.R. Coll1, activities, including information about (daily and sub-daily) scales. 4 where the recovered observations are Dynamical reanalyses provide a complete A. Klein Tank ASRv2 products may be used to force freely accessible. Under the EURO M- representation of the observed state of 1 Centre for Climate Change, University 4 other environmental models, verify DARE effort, about 2.7M station-values the climate at a given point in time. The Rovira i Virgili, Tarragona, Spain regional processes, or aid in the siting of of daily (sub-daily) maximum and quality of that representation depends future observation networks. 2 Climatic Research Unit, School of minimum temperatures and precipitation on many things, but it depends most Environmental Sciences, University of (sea level pressure) observations were fundamentally on the observations East Anglia, Norwich, United Kingdom recovered from observing sites in North assimilated. In order to produce a 3 Sveriges Meteorologiska och African, Middle East and Mediterranean reanalysis which represents the past Hydrologiska Institut (SMHI), Sweden countries. variability and evolution of the climate as faithfully as possible, a large amount 4 Koninklijk Nederlands Meteorologisch The focus was placed on extending back of work is required to prepare the Instituut (KNMI), Netherlands in time those key records that have the observations before they can be used, In the last years and under the EU potential to complete as far as possible either to provide boundary conditions or funding support, two research projects the instrumental record, covering since to be assimilated. have significantly enhanced climate the second half of the 19th century up to the present, while ensuring their quality. This overview presentation will consider data availability and accessibility from The dataset was made freely accessible the different types of work required land surface stations over Europe and through several international databanks (e.g. data rescue, quality control, adjacent regions. and repositories. homogenisation, uncertainty estimation) The EURO4M (European Reanalysis and and use specific illustrative examples Observations for Monitoring) project Under the UERRA-DARE component, from the physical domain (atmosphere, (2009-2013) was aimed at supporting about 9M (~178M) of station values ocean and cryosphere) from both timely and reliable climate services were recovered (gathered from open satellite and in situ sources of observed to monitor variations and change of data sources in Catalonia, Norway and information. European climate, while the UERRA Sweden) over European data-sparse (Uncertainties in Ensembles of Regional sub-regions for pre- and post-1950, while their quality and spatial homogeneity

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 22 Section 2

The process involves recovering the for Climate and Global Change, University Backward extension has been greatly Data Recovery Effort of Nimbus digital data files from the tapes as well of Graz, Austria) A Sterin (Russian Research facilitated by activities at ECMWF to era Observations by the NASA as scanning images of the data from film Institute for Hydrometeorological convert upper air data collected within GES DISC strips. This presentation will address Information, Russia) A Stickler (Oeschger the EU FP7 project ERA-CLIM(2) into the status and challenges of recovering Center for Climate Change Research, the so-called ODB format, which can Author James Johnson the Nimbus data. The old data products University of Bern, Switzerland) MA Valente be directly read in by the Copernicus Affiliation ADNET/NASA GES DISC were written on now obsolete hardware (Instituto Dom Luiz, Faculty of Science of the reanalysis data assimilation system and Co-authors systems and outdated file formats. University of Lisbon, Portugal) is convenient for other use cases as well. James E. Johnson(1,2), Asghar They lack any metadata standards and Due to availability of better reference It is well known that radiosonde data Esfandiari(1,2), Emily Zamkoff(1,3), Atheer each product is often written in its own data (ERA-preSAT, JRA-55 and also need bias correction before they can Al-Jazrawi(1,4), Irina Gerasimov(1,2), Gary proprietary file structure. This requires surface data only reanalyses) the overall be used for climate reanalyses. Most Alcott(1)1. Goddard Earth Sciences Data creating metadata by reading the quality of the adjustments could be reanalyses rely on bias corrections and Information Services Center (GES contents of the old data files. improved as well. calculated offline using (semi)automatic DISC), NASA GSFC, Greenbelt, MD, The job is tedious and laborious, as homogeneity adjustment methods. Comprehensive comparisons with United States.2. ADNET Systems, Inc., documentation may be incomplete, data One approach is to analyse subdaily available satellite data and reanalysis Rockville, MD, United States.3. KBR files and tapes are sometimes corrupted, time series of differences between data are provided. The potential Wyle Systems, Inc., McLean, VA, United or were improperly copied at the time background forecasts of a previous impact of making radiosonde records States.4. Telophase Corporation, they were created. reanalysis cycle (bg) and observation consistent with reprocessed GPS-RO Arlington, VA, United States. records (obs) for break detection. For measurements in the 2006-2016 period is also assessed. The adjustments are NASA launched seven Nimbus break adjustment, one can either use Homogenized radiosonde expected to significantly reduce the meteorological satellites in the 1960s and again the bg-obs time series or one temperature data for climate rejection rate of radiosonde temperature 70s. These satellites carried instruments can use composites of neighbouring reanalyses observations as well as the biases of for making observations of the Earth radiosondes. the resulting reanalyses such as the first in the visible, infrared, ultraviolet, and Author Leopold Haimberger Adjustments from both methods (called Copernicus climate reanalysis ERA5. microwave wavelengths. The original Affiliation University of Vienna RAOBCORE/RICH) have been used data archive consisted of a combination Co-authors in many contemporary reanalyses of magnetic tapes and various film L Haimberger (Department of Meteorology assimilating these data. Since the last media. As these media are well past their and Geophysics, University of Vienna, major release of this data set in 2012 expected end of life, the valuable data Austria) H Hersbach (European Centre for several improvements could be realized, they contain are now being migrated to Medium-Range Weather Forecasts, UK) P most notably the adjustment of annual the GES DISC modern online archive. Dahlgren (European Centre for Medium- variations of the radiosonde observation Range Weather Forecasts, UK) S biases, better adjustment of short time Brönnimann (Oeschger Center for Climate series and of time series with gaps, Change Research, University of Bern, backward extension of adjustments to Switzerland) S Jourdain (Meteo-France, 1939 and forward extension to 2016. France) Florian Ladstätter (Wegener Center for Climate and Global Change, University of Graz, Austria) A. Steiner (Wegener Center

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 23 Section 2

organisations together with sustained in- Atmosphere Data Set (ICOADS) is the A reprocessing would permit an improved The Copernicus Climate Change kind collaboration with NOAA’s National most complete archive of surface marine quantification of uncertainty. Firstly a Service Global Land and Marine Centers for Environmental Information. observations and is widely used in the review of the available documentation construction of marine climate records and formats would provide additional Observations Database: Plans We shall present the overarching plans and in reanalysis. information on data precision and the and progress to date for service provision, and highlight the impact of any conversions on data progress to date in creating an inventory Author Peter Thorne ICOADS provides open access to a quality. Secondly a comparison of of data holdings from disparate available surface marine data from a variety of duplicate observations originating from Affiliation Maynooth University sources. We shall highlight an initial different platform types (including ships, the same original report, but subject to Co-authors forthcoming test release of the data and moored and drifting buoys and fixed differences in data management, would P. W. Thorne (Maynooth University), the schedule of further releases. The platforms) and importantly keeps the enable an improved assessment of this C. Voces (Maynooth University), M. J. service must meet key stakeholder needs multivariate marine record together in contribution to data uncertainty. Menne (NOAA NCEI), E. Freeman (NOAA if it is to be successful. Therefore we a common format. In recent years the NCEI), R.J.H. Dunn (Met Office), D. Berry strongly welcome constructive feedback importance of identifying observations Other anticipated benefits of (NOC), A. Stephens (STFC) both during and after the event. Formal made on the same ship or platform reprocessing include recovery of channels for feedback will be highlighted. has become more apparent as the additional data and metadata and The Copernicus Climate Change Service sophistication of error models for marine improved consistency. Global Land and Marine Observations data has increased. Identification of the Database service aims to produce The benefits for reanalysis of observations made on the same platform improved surface meteorological data EUMETSAT Data Records in reprocessing the surface marine is also a key requirement for reanalysis. holdings across domains, timescales, climate record Unfortunately the marine data in ICOADS Support of Reanalysis and Essential Climate Variables. contains many observations without Substantial efforts will be made to Author Elizabeth Kent Author Jörg Schulz identifiers as substantial amounts of integrate holdings, ensuring consistency Affiliation National Oceanography Affiliation EUMETSAT historical data were derived from sources across and between timescales (sub- Centre that had not retained ship identifier Co-authors daily, daily and monthly), and to improve J. Schulz (EUMETSAT), C. Anderson Co-authors information. aspects of data discovery and access. E. C. Kent (National Oceanography (EUMETSAT), M. Doutriaux-Boucher We will illustrate, using examples from The data shall be served to users under Centre), D. I. Berry (National (EUMETSAT), T. Hanschmann a probabilistic trajectory estimation, a common data model as a set of Oceanography Centre), E. Freeman (EUMETSAT), Tim Hewison (EUMETSAT), how the methods used to combine fundamental data holdings suitable for (National Centers for Environmental V. O. John (EUMETSAT), A. Lattanzio marine surface data from different use in myriad applications, including Information), S. J. Worley (National (EUMETSAT), C. Marquardt (EUMETSAT), historical archives can affect quality and reanalyses. The service started in Center for Atmospheric Research)The R. Roebeling (EUMETSAT), F. Rüthrich consistency. Focussing on requirements March 2017 and, subject to satisfactory surface marine observational record is an (EUMETSAT), and T. Tabata (MSC/JMA) important input data source for all for reanalyses, we will demonstrate how performance, shall run for four years with EUMETSAT addresses climate reanalyses. The observations are used reprocessing of historical marine surface incremental improvements in service monitoring by delivering advanced for assimilation, but for atmospheric data holdings would improve the quality provision over its lifetime. It brings multi-satellite programmes with long- reanalyses are also used for construction of the marine climate record. together a number of key European term commitment, maintaining a unique of sea surface temperature gridded archive of decades of space-based analyses used as the lower boundary. observations, producing consistent The International Comprehensive Ocean-

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 24 Section 2 climate data records, providing easy data records significant improvements The HOAPS climate data records are intrusions, moonlight intrusions, and access and supporting climate-related in calibration, multi-instrument time primarily based on passive microwave reflector emissivity have been accounted capacity building initiatives. This involves series harmonisation and/or uncertainty measurements from the SSM/I (Special for and the brightness temperatures specific scientific and technical efforts characterisation has been achieved. In Sensor Microwave/Imager) sensor family. have been inter-calibrated to the SSM/I for the re-calibration of historical satellite addition, EUMETSAT is also providing instrument series to allow a seamless In order to derive reliable long term data and the extraction of climate data Atmospheric Motion Vector data records continuation of existing TCDRs. trend estimates of the global water and records. from Meteosat and AVHRR data that energy cycle parameters it is strictly In order to extend the available FCDR to have been consistently reprocessed for In particular, the scientific analysis of necessary to carefully correct for all the time period before the SSM/I epoch, the usage in re-analysis. raw satellite data leading to corrections known problems and deficiencies of CM SAF has now reprocessed available of artefacts, improved calibration of The presentation will provide an overview the SSM/I radiometers as well as to brightness temperatures from the SMMR individual instruments and harmonisation of EUMETSAT’s recent scientific and inter-calibrate and homogenise the (Scanning Multichannel Microwave of several satellite instruments in a technical advances and prospects for different instruments. Moreover, all Radiometer) on board Nimbus-7 with the time series is fundamental to serve the providing useful satellite data records for applied corrections need to be clearly main focus on the inter-calibration of the generation of physically consistent data reanalysis. documented to provide a complete brightness temperatures to the SSM/I records of geophysical variables by calibration traceability for a Fundamental series, using ERA20c as a transfer target. reanalysis or the application of retrieval Climate Data Record (FCDR). The re-processed data record will be methods. With the participation in the EU A Fundamental Climate Data available in the same user friendly data Following these recommendations, CM ERA-CLIM, ERA-CLIM2 and FIDUCEO Record of SSM/I, SSMIS, and format as the existing FCDR. The new SAF released in 2013 a FCDR of SSM/I projects EUMETSAT has developed SMMRbrightness temperatures FCDR release will also extend the SSMIS brightness temperatures (DOI:10.5676/ dedicated capabilities and capacities data record with two additional years. Author Fennig Fennig EUM_SAF_CM/FCDR_SSMI/V001), freely to deliver consolidated Fundamental Altogether, the FCDR will now span the available from the web user interface Climate Data Records useful for global Affiliation Deutscher Wetterdienst time period from 1978 to 2015 combining (http://wui.cmsaf.eu/). This FCDR has reanalysis. Co-authors observations from SMMR, SSM/I and already been used in the ESA CCI Sea Karsten Fennig (DWD, Offenbach, SSMIS. The developments are utilised in support ice project and will also be used in the Germany), Marc Schröder (DWD, to the Copernicus Climate Change upcoming reanalysis ERA5. In order to This presentation will focus on the Offenbach, Germany), Axel Andersson Service where EUMETSAT is delivering further extend the HOAPS dataset in inter-calibration of the SMMR and the (DWD, Hamburg, Germany) further consolidated data records for time, the SSM/I successor instrument evaluation of the combined FCDR over many of its own satellite missions but The satellite based HOAPS (Hamburg SSMIS (Special Sensor Microwave the complete time period. A validation also for satellites instruments from other Ocean Atmosphere Parameters and Imager Sounder) has to be used from of the brightness temperatures is a space agencies ranging back into the late Fluxes from Satellite Data; http://www. 2009 onwards. challenging task as there are no ground- 1970s. The instrument records addressed truth reference measurements available oaps.org/) climatology provides climate CM SAF also reprocessed the SSMIS range from infrared and microwave for the microwave band. Hence, the data records of precipitation, evaporation sensors onboard F16, F17, and F18 to sounding and imaging, radio occultation homogeneity of the FCDR is evaluated by and the resulting freshwater flux over the same standards as the SSM/I data to scatterometer instruments. an analysis of the relative biases between the global ice-free ocean between record for the time period 2006 – 2013 the different instruments before and after For instance instruments considered for 1987 and 2008. The latest version of and the combined FCDR was released the inter-calibration offsets are applied. infrared sounding range from historic HOAPS has been released by CM SAF in 2015 (DOI:10.5676/EUM_SAF_CM/ HIRS on NIMBUS-6 to the modern IASI and is available from the CM SAFs web FCDR_MWI/V002). Amongst others, on Metop platforms. For each of the user interface (http://wui.cmsaf.eu/). known instrument issues like sunlight

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 25 Section 2

GRACE is therefore unique among Observing Mass Variability in the the currently available remote sensing Earth System with the Satellite concepts since it is susceptible to mass Gravity Missions GRACE and changes independently of its surface GRACE-FO exposition. In view of the already available 15 years of data acquired by Author Henryk Dobslaw the GRACE mission and the prospect Affiliation Helmholtz Centre of a continuation of the gravity-based Potsdam, German monitoring of terrestrial water storage Research Centre for with GRACE-FO, which is scheduled for Geosciences launch in February 2018, it is now very promising to attempt the incorporation Co-authors of gravity-based indicators into Henryk Dobslaw (Helmholtz Centre hydrometeorological re-analysis efforts. Potsdam, German Research Centre for Geosciences, Department 1: Geodesy) This presentation will provide an overview on the current accuracy of GRACE- The satellite mission GRACE was based water storage estimates and will specifically designed to map the Earth’s demonstrate by means of a number of time variable gravity field: since 2002, dedicated examples the potential value two twin satellites are trailing each of satellite gravimetry when compared other with a distance of 220 km at a to other availabe observations of th e very low altitude of about 400 km in a terrestrial branch of the water cycle. near-polar orbit. Continuous distance measurements between the spacecraft allow for the mapping of the gravity potential from data accumulated over 30 days only, thereby providing a time-series of the global mass distribution at and beyond the Earth’s surface with monthly resolution. Over the continents, time-variations in the gravity field as observed by GRACE are dominated by changes in the water masses in different hydrological storages, which includes surface water, snow mass, soil moisture at various depth levels, and even groundwater residing in the deep aquifers.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 26 Minimization of this Lagrangian is (20th century coupled climate reanalysis Section 3 – Methods achieved through adequate variation of Uncertainty estimation in system supported by the EU ERA-CLIM for reanalyses elements of the very high-dimensional modern reanalysis systems and ERA-CLIM2 R&D projects). uncertainty or control space(consisting All systems are using a 10-member initial and boundary conditions as well Author Andras Horanyi ensemble, on which uncertainty Dynamically and kinematically as model parameter fields) as informed Affiliation ECMWF estimates are based. The presentation consistent global ocean state by the adjoint model. As practiced by the Co-authors will focus on the diagnosis of the and parameter estimation in “Estimating the Circulation and Climate G. Biavati (ECMWF), P. Dahlgren uncertainty information as provided of the Ocean” (ECCO) consortium and support of climate research (ECMWF), H. Hersbach (ECMWF), A. by these EDA systems. Some relevant targeting the era of global coverage by Horanyi (ECMWF), J. Muñoz-Sabater specific scientific questions will be Author Patrick Heimbach satellite altimetry, the optimal state and (ECMWF) and R. Radu (ECMWF) discussed as for example the spatial- Affiliation University of Texas at parameter estimates fulfill conservation temporal variability of the reanalysis Austin laws exactly over the full multi-decadal Uncertainty information is an integral uncertainty information or how estimation period, as it avoids unphysical part of any meteorological analysis and Co-authors uncertainties in the verifying truth can analysis increments at regular periods prediction system and provides essential Patrick Heimbach (University of Texas influence the validation of uncertainty at Austin, USA) throughout the estimation process. added value to the users. Estimates of uncertainty are also important in estimation. Finally guidance will be given Understanding the global full-depth Closed property budgets so inferred reanalysis but are not provided with how this information can be best used for ocean circulation, attributing its provide valuable information for ocean all currently available data sets. At the the reanalysis user community. evolution and changes on seasonal to and climate science. Remaining European Centre for Medium-Range multi-decadal time scales, inferring its systematic misfits or unphysical control Weather Forecasts (ECMWF) various adjustments point to either remaining Impact of Optimal Assimilation role in the global climate system, and reanalysis systems have been produced Windows in Coupled Data quantifying related uncertainties are model inadequacies or unrealistic to date, or are currently in production, hampered by sparse and heterogeneous uncertainty estimates. which includes uncertainty estimates. Assimilation on AMOC Analysis observations, an inherently turbulent The sustained multi-decadal production This is possible by using the Ensemble of Author Shaoqing Zhang fluid, imperfect models, and uncertain effort by ECCO is entering a new phase Data Assimilation (EDA) technique. The Affiliation Ocean University forcing functions. with a special emphasis on the ocean’s EDA system provides flow-dependent of China impact on, and the imprints from the Viewed as a very large-scale estimation background errors for the data Co-authors interaction with the polar ice sheets, and problem, the goal is to find an optimal assimilation system in the reanalysis, but Shaoqing Zhang, Lv Lu, Xiaopeilin and their role in global and regional sea level state and parameter estimate through in addition, the spread of the EDA can Lixin Wu(Physical Oceanography Key change. fitting a state-of-the art circulation also be used for uncertainty estimates of Laboratory of Ministry of Education, model to all available observations the reanalysis products. ECMWF is in the Ocean University of China, and Qingdao while fulfilling underlying conservation production phase of ERA5 (implemented National Laboratory for Marine Science laws and equations of motion. To do so by the Copernicus Climate Change and Technology) we formulate a variational problem in Service on behalf of the European which a weighted squared model-data Commission) and has produced the Climate signals are the results of misfit function is augmented by the ERA-20C and CERA-20C reanalyses interactions of multiple time scale media model equations via Lagrange Multiplier such as the atmosphere and ocean in Method. the coupled earth system. Coupled data

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 27 Section 3 assimilation (CDA) pursues balanced and 4D-Var control variable. We present a produced by GMAO, and provides global coherent climate analysis and prediction The ECMWF weak-constraint formulation of weak constraint with a data spanning the period 1980-present. initialization by incorporating observations 4D-Var formulation and a model error forcing term active in the The atmospheric data assimilation from multiple media into a coupled model. comparison between 12 and 24 stratosphere above 40 hPa, and show component of MERRA-2 used a 3D-Var results of assimilation trials using the scheme, which was operational at the time Given different time scales of hour assimilation window length ECMWF IFS atmospheric model. Results of its design. Since then, a Hybrid 3D-Var characteristic variability in different to produce recommendations for show improvements in the short-range then a Hybrid 4D-EnVar were implemented, media, an optimal assimilation window future reanalysis as part of the forecast fits to observations, and this adding an ensemble component to the (OAW) exists for each medium. With a ERACLIM2 project formulation of weak-constraint 4D-Var data assimilation scheme. simple coupled model that simulates was made operational at ECMWF in typical scale interactions in the climate Author Jacky Goddard In this work, we will be examining the November 2016. system, we first show that an OAW in Affiliation ECMWF benefits of using hybrid ensemble flow- each medium can provide maximal Attempts to extend the model error dependent covariances to represent Co-authors observational information that best fits forcing to the rest of the atmosphere errors and uncertainties in historic J Goddard (ECMWF), P Laloyaux characteristic variability of that medium have so far been unsuccessful due to periods. Specifically, periods of pre- and (ECMWF), M Fisher (ECMWF – retired), during the data belending process. problems with erroneous interpretation of post-satellites, as well as periods of Y Trémolet (NCAR/UCAR), S Lang aircraft observation error as model error. active tropical cyclone seasons. Then we apply the idea to a coupled (ECMWF) Characterising the statistical properties general circulation model and its data Finally, we will also be exploring the use of model error is one of the main assimilation system to study the impact In most operational implementations of adaptive localization scales. current problems in the weak-constraint of OAWs on climate analysis by recovering of four-dimensional variational data 4D-Var. Future work will aim to improve important characteristic variability such assimilation (4D-Var) the strong- the specification of the model error as sub-diurnal in the atmosphere and constraint formulation is used. This relies A Method for Snow Reanalysis: covariance matrix. We discuss results diurnal in the ocean more accurately. on the assumption that the numerical The Sierra Nevada (USA) from an investigation into 4D-Var window In particular, the features and variability model’s representation of the evolution Example length, 12 hour vs 24 hour, with both of Atlantic Meridional Overturning of atmospheric flow is perfect, or at least strong- and weak-constraint 4D-Var. Author Manuela Girotto Circulation has been examined. that the model errors are small enough to be neglected compared to other errors in Affiliation USRA, GMAO the system. Using hybrid data assimilation Co-authors As other aspects of data assimilation for reanalyses Manuela Girotto (Global Modeling and processes have advanced, the validity Assimilation Office, NASA Goddard of this perfect model assumption has Author Amal EL Akkraoui Space Flight Center, Greenbelt, MD, become more questionable. It also limits Affiliation NASA-GMAO/SSAI USA), Steven A. Margulis (Department the length of the atmospheric analysis Co-authors of Civil and Environmental Engineering, window that can be used to roughly 12 Amal EL Akkraoui (NASA-GMAO/SSAI), University of California, Los Angeles, hours. Ricardo Todling (NASA-GMAO) CA, USA), Gonzalo Cortés (Department of Civil and Environmental Engineering, Weak-constraint 4D-Var relaxes the The Modern-Era Retrospective Analysis University of California, Los Angeles, perfect model assumption by explicitly for Research and Applications, version representing model error as part of the 2 (MERRA-2) is the latest reanalysis

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 28 Section 3

CA, USA), Michael Durand (School of Nevertheless, existing simulations with Earth Sciences, and Byrd Polar Research Atmospheric reanalysis for multi Paleoclimate reanalyses as a data assimilation already provide useful Center, The Ohio State University, centuries using historical tool to understand the signal reconstructions of the state of the Columbus, Ohio, USA) weather archives and isotopic recorded by observations over system. They also provide a way to test proxies the past millennium hypotheses about the mechanisms ruling This work presents a state-of-the art past changes or the compatibility of the methodology for constructing snow water Author Kei Yoshimura Author Hugues Goosse interpretation of observations coming from equivalent (SWE) reanalysis. The method Affiliation The University of Tokyo Affiliation Université de Louvain different sources. Examples are provided, is comprised of two main components: (1) in particular focusing on the temperature Co-authors Co-author a coupled land surface model and snow asymmetry between continents in both K Yoshimura (The University of Tokyo), depletion curve model, which is used to Hugues Goosse (Université de Louvain, hemispheres over the last centuries, P Neluwala (The University of Tokyo), generate an ensemble of predictions of ELIC/TECLIM, Belgium) showing the role of the oceanic heat A Okazaki (RIKEN) SWE and snow cover area for a given set storage and transport to explain the of (uncertain) inputs, and (2) a reanalysis Data assimilation has attracted Our systematic instrumental measurement delayed warming of the Southern Ocean step, which updates estimation variables increasing interest in the paleoclimate for meteorological quantities only lasts compared to other regions. to be consistent with the satellite observed community over the past 15 years since 100 years at most, so they are too short depletion of the fractional snow cover time the technique has several advantages to analyze recent big climate changes, series. compared to the empirical-statistical A global climate reconstruction like Little Ice Age or Medieval Warming approaches traditionally used to using data assimilation This method was applied over the Sierra Period. In our research group, we have reconstruct temperature or precipitation Nevada (USA) based on the assimilation of made an offline data assimilation system fields from paleoclimate records. Several Author Stefan Brönnimann remotely sensed fractional snow covered for stable water isotopes and showed our issues still need to be addressed to Affiliation University of Bern area data from the Landsat 5-8 record success to reproduce ENSO changes obtain comprehensive reanalyses, one (1985-2016). The verified dataset (based during 19th to 21st century (Okazaki and Co-authors of the strongest constraint being the S. Brönnimann1 (Oeschger Centre and on a comparison with over 9000 station Yoshimura, 2017). small number of observations, displaying Institute of Geography, University of years of in situ data) exhibited mean and On the other hand, we have made data relatively large uncertainties. Bern), J. Franke1 root-mean-square errors less than 3 assimilation of weather information from and 13 cm, respectively, and correlation Those records are generally only old diaries (Toride et al., 2017). Thus, by Understanding the past behaviour of greater than 0.95 compared with in situ indirectly connected to standard combining those two data assimilation the climate system ideally relies on a SWE observations. climate variables implying that inversion methods, we are trying to make multi- techniques or adequate observation comprehensive view of past climate The method (fully Bayesian), resolution centennial length atmospheric reanalysis operators need to be included in states. However, paleoclimatology is (daily, 90-meter), temporal extent (31 product. At the presentation, I’d like to the assimilation process. Specific often faced with a sparsity of proxies years), and accuracy provide a unique introduce these two new methods and adaptations to data assimilation and a comprehensive view is then only dataset for investigating snow processes. current status of our multi-centennial algorithms are also required to deal with possible with audacious interpretation. This presentation illustrates how the reanalysis project. the records that represent averages over In recent years, new numerical reanalysis dataset was used to provide a periods ranging from a few months to techniques have become available that basic accounting of the stored snowpack several decades and are distributed over derive a best estimate of the climate state water in the Sierra Nevada over the last strongly spatially biased network. by combining the real-world information 31 years and ultimately improve real-time from sparse proxy data with the physics streamflow predictions.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 29 Section 3 of climate models. Such data sets The Whole Atmosphere Model (WAM) The last decade (2004-present) climate variability using a consistent provide a physically consistent, spatially framework assigns to link the terrestrial collections of the MLT data from the set of observations. First results complete picture of the past climate and space weather and climate space and ground provide us opportunity show that CERA-20C improves on system that is in agreement with the applications. Current advances in the to explore their reanalysis in WA models. the representation of atmosphere– proxy records within their errors. WAM developments and in their coupling We overview the current status of data ocean heat fluxes and of mean sea with the ionosphere models depends analysis studies in the WAM/WDAS of level pressure compared to previous We present a 400-year long, monthly, on the comprehensive extension of NOAA and discuss its preparation and reanalyses. global, 3-dimensional climate data data assimilation methods into the challenges for assimilation of data with set that was produced by assimilating At the same time, there are undesirable Mesosphere and Lower Thermosphere strong diurnal signals in the MLT region. historical instrumental data, documentary discontinuities in ocean heat content (MLT). evidence, and tree ring data into a large and an excessive accumulation of Arctic ensemble of climate model simulations In this region of active wave dynamics Earth system climate reanalyses sea ice. CERA-20C provides a ten- using an off-line Ensemble Kalman Filter and strong diurnal cycles the past (UARS) at ECMWF member ensemble climate reanalysis for technique. In addition to evaluations and present (TIMED, EOS-Aura) space- all parameters and levels over the 20th and comparisons of this method with borne observations of wind, temperature Author Patrick Laloyaux century. Ensemble generation is based existing reconstruction, we present and tracers have been analyzed by Affiliation ECMWF on the Ensemble of Data Assimilations analyses of this data sets with respect to models with the top lids placed between Co-authors (EDA) system which explicitly accounts the transition of the climate system from 80-100 km for case studies. The Eric de Boisseson (ECMWF), Per for errors in the observational record and the Little Ice Age climate to the present relatively low positions of the model top Dahlgren (ECMWF), Dinand Schepers in the forecast model. This ensemble climate. lids and 6-hour assimilation windows (ECMWF), Jacky Goddard (ECMWF), Yuki technique aims to provide an indication preclude accurate analysis for diurnal Kosaka (ECMWF), Magdalena Balmaseda of the confidence in the data. and sub-diurnal upward-propagating (ECMWF), Kristian Mogensen (ECMWF), Reanalysis in the Whole tides that deliver impacts of “terrestrial” Atmosphere Models: From Dick Dee (ECMWF), Roberto Buizza perturbations and stratospheric climate (ECMWF) Nudging Techniques to Data anomalies into the space weather/climate Analysis in the Mesosphere and domain. The European Centre for Medium- Range Weather Forecasts is a key Lower Thermosphere In this paper we discuss methods to player in the production of reanalyses constrain the dynamics and transport of Author Valery Yudin for climate monitoring and research. the multi-year WA predictions below the Colorado University, Following the Earth system approach Affiliation stratopause using the 2007-2016 MERRA CIRES embraced in the new ten year strategy, a data to achieve the first outlook on the coupled assimilation system that ingests Co-authors day-to-day, annual and year-to year simultaneously ocean and atmospheric V. Yudin (CU/CIRES), D. Kleist (NCEP/ variations of the mean flow, planetary observations in a coupled ocean- EMC), K. Howard (NCEP/EMC), T. Fuller- waves and tides. We will verify realism atmosphere model has been developing. Rowell (CU/CIRES), S. Karol (CU/CIRES), of two WAM predictions of NOAA and R. Akmaev (NOAA/SWPC), A. Kubaryk NCAR constrained by MERRA by MLS, This approach has been used to (NCEP/EMC). TIDI and SABER observations along with produce a new coupled 20th-century ground-based measurements. reanalysis, called CERA-20C, which provides a long record of low-frequency

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 30 relevance to SPARC, and to contribute these species are represented in the Thus, the fidelity of reanalysis Section 4 – Evaluation to future improvements in the reanalysis existing global reanalyses, and whether stratospheric WV is sensitive to how and intercomparisons products by establishing collaborative or not significant differences exist accurately the fundamental drivers links between reanalysis centres and amongst them. of stratospheric WV such as tropical of reanalyses data users. tropopause layer temperatures, methane We present results from the WV and O 3 oxidation, and the stratospheric The emphasis is on diagnostics of intercomparisons that were performed overturning circulation are represented. Results from the SPARC the upper troposphere, stratosphere, as part of the SPARC (Stratosphere- Because of these issues and the known Reanalysis Intercomparison and lower mesosphere. In the talk, an troposphere Processes and their Role deficiencies in the representation of Project (S-RIP) during 2013-2017 overview of the S-RIP activity during in Climate) Reanalysis Intercomparison stratospheric transport in reanalyses, 2013-2017 is made, and some scientific Project (S-RIP). Author Masatomo Fujiwara we find much poorer agreement highlights are presented and discussed. Affiliation Hokkaido University Comparisons are made over a range both amongst reanalyses and of timescales between the different between reanalyses and independent Co-authors reanalyses, and between reanalyses observations. For these reasons, M. Fujiwara (Hokkaido Univ., Japan), Assessment of upper and observational datasets. In addition stratospheric WV from the current G. L. Manney (NWRA and New Mexico tropospheric and stratospheric to the intercomparisons, we discuss the generation of reanalyses should generally Tech, USA), L. J. Gray (Oxford Univ. and water vapor and ozone in treatment of WV and O in reanalyses not be used in scientific studies. NCAS, UK), J. S. Wright (Tsinghua Univ., 3 reanalyses as part of S-RIP to aid future research and guide the China), and the S-RIP team Author Sean Davis interpretation of differences between the reanalysis fields. Because total column Preliminary assessment of The climate research community uses Affiliation NOAA ESRL global atmospheric reanalysis data sets ozone (TCO) is assimilated in the newer the ERA5 ozone reanalyses Co-authors to understand a wide range of processes reanalyses, these reanalyses generally S.M. Davis (NOAA ESRL), M.I. Hegglin Author Rossana Dragani and variability in the atmosphere, yet reproduce TCO well except when data (Univ. Reading), M. Fujiwara (Hokkaido Affiliation ECMWF different reanalyses may give very coverage is lacking, such as during Univ.), R. Dragani (ECMWF), Y. Harada different results for the same diagnostics. polar night. Co-authors (JMA), C. Kobayashi (MRI/JMA), C. Long The Stratosphere–troposphere RD Dragani (ECMWF), HH Hersbach (NCEP/NOAA), G.L. Manney (NWRA/New We find that the vertical distribution of Processes And their Role in Climate (ECMWF), CS Soci (ECMWF) Mexico Tech.), E. Nash (SSAI), G.L. Potter ozone is relatively well represented in (SPARC) Reanalysis Intercomparison (NASA GSFC), S. Tegtmeier (GEOMAR), reanalyses, particularly given that for ECMWF is currently producing the Project (S-RIP, https://s-rip.ees.hokudai. T. Wang (NASA JPL), K. Wargan (NASA most reanalyses there are only weak ERA5 reanalysis that will replace the ac.jp) is a coordinated activity to GMAO), J.S. Wright (Tsinghua Univ.) constraints on the vertical profile of widely-used ERA-Interim atmospheric compare reanalysis data sets using a ozone from observations and that most reanalysis. Produced as part of the variety of key diagnostics. Reanalysis datasets are widely used have a simplistic representation of ozone EU-funded Copernicus Climate Change The objectives of this project are to to understand atmospheric processes photochemical processes. In contrast Service, ERA5 will be open and freely identify differences among reanalyses and past variability, and are often used to O3, stratospheric WV data are not available to all. The ERA5 reanalysis and understand their underlying causes, as “observations” for comparison currently assimilated, with humidity is based on a significantly different to provide guidance on appropriate with climate model output. Because observations typically used only in the and, in general, much-improved data usage of various reanalysis products in of the central role of water vapor (WV) troposphere below a specified vertical scientific studies, particularly those of and ozone (O3) in climate change, it is level at or near the tropopause. important to understand how accurately

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 31 Section 4 assimilation system compared to its Chemistry-climate model simulations have AoA up to one year younger than ERA-I climate implications it carry alongside. predecessor, including in its ozone shown that the mean age of stratospheric while MERRA delivers AoA up to one The present study attempts to bring component. air (AoA) is a good indicator of the strength year older. Such large disagreements out the subtropical climate change of the residual circulation, and that at of AoA values are found in the whole indications in the comparatively new The ERA5 ozone reanalyses benefit from multi-decadal timescales it is expected to stratosphere. Japanese Re-analysis (JRA55) dataset largely reprocessed datasets, many decrease with rising levels of greenhouse by means of the mean meridional stream of which were generated with special The time evolution also differs gases in the atmosphere. Satellite function (MSF). attention to climate and reanalyses considerably depending on the reanalysis observations of stratospheric tracers SF6 applications, e.g. those retrieved as part of considered, e.g. JRA-55 delivers AoA The observed features of HC in JRA55 and HCl indicate that AoA did decrease the ESA-funded Climate Change Initiative. trends over 2002-2012 which are nearly are found to be reproduced in NCEP, in the Southern Hemisphere during the Compared to ERA-Interim, ozone-sensitive insignificant in the Northern Hemisphere MERRA and ECMWF datasets, with first decade of this century but also that radiances in the infrared (IR) from several and display no detectable dipole structure notable differences in the magnitudes of it increased in the Northern Hemisphere. IR sounders are assimilated in ERA5. between the two hemispheres. Hence the MSF. The calculated annual cycle of HC This dipole structure of AoA trends multi-annual to multi-decadal evolution edges, center and total width from this A variational bias correction model was has been confirmed by transport of AoA depicted by modern reanalyses is dataset closely resembles the annual implemented for ozone observations simulations driven by the ERA-Interim not yet sufficiently clear or consistent to cycle of the respective parameters to improve the data exploitation and reanalysis but not by in situ observations be used as a diagnostic for the evaluation derived from the rest of the datasets, remove potential inter-instrumental biases in the stratospheric northern mid- of chemistry-climate models. with very less inter-annual variability. that normally affect different datasets latitudes, which have not yet delivered of the same quantity causing a loss of For the first time, MSF estimated using any significant trend over a forty-year performance when jointly assimilated. four reanalysis datasets (JRA55, NCEP, time period. Hence further research Assessment of Hadley Cell MERRA and ECMWF datasets) are In this contribution, we will first introduce is required about the magnitude, Dynamics in JRA55 Reanalysis verified with observations from integrated the ERA5 ozone system, and discuss distribution and detectability of AoA Data radiosonde archive (IGRA) datasets, the differences from its predecessors, trends. As part of the SPARC Reanalysis Author Sneha Mathew using the process of subsampling. and then present some results from a Intercomparison Project (S-RIP), we have The features so estimated show a preliminary assessment of the quality of developed a pre-processor to feed a Affiliation SpacePhysics high degree of similarity among each the ERA5 ozone reanalyses. Eulerian transport model with any of the Laboratory, VSSC other as well as with observations. The available global (re-)analysis datasets. Co-authors monthly trend in the total width of the Sneha Susan Mathew (Space Physics This allowed us to compute the age of HC is quantified to show a maximum Mean age of stratospheric air Laboratory, VSSC, Thiruvananthapuram, air in the stratosphere and its evolution of expansion during the month of since 1985: large disagreements India ), K. KishoreKumar (Space Physics from 1985 to 2015, according to five July, which is significant at the 95% between five modern reanalyses Laboratory, VSSC, Thiruvananthapuram, modern reanalyses: ERA-Interim, JRA- confidence interval for all datasets. India ) Author Simon Chabrillat 55, MERRA, MERRA-2 and CFSR/ The present study also discusses the CFSv2. Our results compare favorably Affiliation BIRA-IASB Hadley Circulation (HC) is a planetary presence of a ‘minor circulation’ feature with those published previously using Co-authors scale circulation spanning one-third in the northern hemisphere (NH) which ERA-Interim. It turns out that the other S. Chabrillat (BIRA-IASB), Y. Christophe of the globe from tropics to the sub- is centered on 34°N during the June and reanalyses deliver surprisingly different (BIRA-IASB), C. Vigouroux (BIRA-IASB), tropics. Recent changes in HC width July months, but not in all years. The and diverse results. For example at 20km Q. Errera (BIRA-IASB), E. Mahieu (U. Lg) and its temporal variability is a topic significance of the present study lies height and for year 2000, JRA-55 delivers of paramount interest because of the in evaluating the relatively new JRA55

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 32 Section 4 dataset with widely used reanalysis is presented, which takes into account Because correcting the precipitation datasets and radiosonde observations surface mass and associated enthalpy Land surface precipitation and within the coupled atmosphere-land and revelation of a minor circulation not fluxes and is independent of reference hydrology in MERRA-2 modeling system allows the MERRA-2 discussed hitherto in the context of HC temperature in the steady state. near-surface air temperature and dynamics. Author Rolf Reichle humidity to respond to the improved Using atmospheric data from ECMWF’s Affiliation NASA/GSFC precipitation forcing, MERRA-2 ERA-Interim and JMA’s JRA-55 provides more self-consistent surface reanalyses, several resulting implications Co-authors Towards consistent diagnostics meteorological data than were available are illustrated. First, it is shown that R. H. Reichle (NASA/GSFC),R. D. Koster of the coupled atmosphere and from the earlier, offline MERRA-Land material surface energy fluxes (including (NASA/GSFC), C. S. Draper (NASA/GSFC ocean energy budgets reanalysis. Overall, MERRA-2 land snowfall) globally have a net cooling effect and USRA/GESTAR), Q. Liu (NASA/GSFC hydrology estimates are better than those Author Michael Mayer on the Earth’s surface (-1.3Wm-2), with and SSAI), M. Girotto (NASA/GSFC and USRA/GESTAR), S. P. P. Mahanama of MERRA-Land and MERRA. Affiliation University of Vienna much larger regional values. This implies that the non-material (radiative plus (NASA/GSFC and SSAI), G. J. M. De A comparison against GRACE satellite Co-authors turbulent) surface energy flux (FS) must Lannoy (KU Leuven), and G. S. Partyka observations of terrestrial water storage M. Mayer (University of Vienna), be higher than previous estimates in order (NASA/GSFC and SSAI) demonstrates clear improvements in L. Haimberger (University of Vienna), to balance the material surface energy MERRA-2 over MERRA in South America J. Edwards (UK Met Office), P. Hyder The Modern-Era Retrospective Analysis flux and the observed ocean warming. and Africa but also reflects known errors (UK Met Office) for Research and Applications, version in the observations used to correct the Second, the agreement between fields 2 (MERRA-2), provides global, 1-hourly MERRA-2 precipitation. The MERRA-2 The widely used diagnostic vertically of FS inferred from satellite-measured estimates of land surface conditions and MERRA-Land surface and root zone integrated total energy budget equations radiation and reanalysis-based for 1980-present at ~50-km resolution. soil moisture skill vs. in situ measurements of atmosphere and ocean are re- divergence of atmospheric lateral energy Outside of the high latitudes, MERRA-2 is slightly higher than that of ERA-Interim/ examined and several inconsistencies are transports with independent surface flux uses observations-based precipitation Land and higher than that of MERRA revealed. First, there is a dependence on products is substantially improved when data products to correct the precipitation (significantly for surface soil moisture). reference temperature because enthalpy using the here-presented instead of the falling on the land surface. fluxes associated with precipitation and commonly used budget formulation. This paper describes the precipitation Snow amounts from MERRA-2 have evaporation (material surface energy lower bias and correlate better against Third, results imply that previous correction method and evaluates the fluxes) are usually neglected. reference data than do those of MERRA- studies seriously underestimated cross- MERRA-2 land surface precipitation Land and MERRA, with MERRA-2 skill Regional biases introduced by this equatorial atmospheric and oceanic and hydrology. Compared to monthly roughly matching that of ERA-Interim/ shortcoming are order 20Wm-2 and energy transports. Overall, the improved GPCPv2.2 observations, the corrected Land. Seasonal anomaly R values against strongest in the tropics. A second framework allows for unambiguous energy MERRA-2 precipitation (M2CORR) is naturalized streamflow measurements ambiguity arises from different reference budget diagnostics based on reanalyses better than the precipitation generated in the United States are, on balance, states of water in the climate system: and will help to provide more reliable by the atmospheric models within highest for MERRA-2 and ERA-Interim/ vapor at 0K in the atmosphere and benchmark values for validation purposes. the cycling MERRA-2 system and the liquid at 0°C in the ocean. Additionally, earlier MERRA reanalysis. Compared Land, somewhat lower for MERRA-Land, small inconsistencies in formulations of to 3-hourly TRMM observations, the and lower still for MERRA. the energetics of current weather and M2CORR diurnal cycle has better climate models are highlighted. A more amplitude but less realistic phasing than consistent energy budget framework MERRA-2 model-generated precipitation.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 33 Section 4

that includes remote sensing data and atmosphere coupling. Yet, our results show atmosphere is coupled with the NEMO Quantifying spatio-temporal gridded station observations on the that precise conclusions about the soil model for the ocean and to the LIM2 variations of soil moisture control other hand. For the relation between soil moisture-temperature coupling strength model for sea ice. moisture and evaporative fraction three are still uncertain due to the limited on surface energy balance and The in-situ products of the Global key parameters are estimated: 1) the availability of adequate observations. near-surface air temperature Precipitation Climatology Center (GPCC) frequency of the occurrence of different were used as a reference: The Full Author Clemens Schwingshackl soil moisture regimes, 2) the sensitivity Data Monthly (FDM) (Schneider et al., of evaporative fraction to soil moisture Assessment of precipitation Affiliation ETH Zürich 2014) containing global land surface variations in the transitional soil moisture in the CERA-20C and ERA-20C Co-authors precipitation from 1901 to 2013 with regime, and 3) the critical soil moisture reanalyses by means of C Schwingshackl (Institute for monthly resolution, and the Full Data value which separates water- and energy- Atmospheric and Climate Science, ETH precipitation gauge observations Daily (FDD) (Schamm et al., 2014) from limited evapotranspiration regimes. Zurich, Switzerland), M Hirschi (Institute Author Elke Rustemeier 1988 to 2013 with daily resolution. for Atmospheric and Climate Science, All used datasets agree well in the overall For both data sets, the respective Affiliation Deutscher Wetterdienst ETH Zurich, Switzerland), SI Seneviratne geographical distribution of the single overlapping period was chosen for the (Institute for Atmospheric and Climate soil moisture regimes, but there are Co-authors evaluation, 23 years (1988-2010) for FDD Science, ETH Zurich, Switzerland) differences in the classification in some E Rustemeier (1), M Ziese (1), A Meyer- and 110 years (1901-2010) for FDM with distinct regions. Regarding the sensitivity Christoffer (1), U Schneider (1), P Finger 1° spatial resolution. Soil moisture plays a crucial role for the of evaporative fraction to soil moisture (1), A Becker (1)(1) Deutscher Through annual and seasonal totals, a energy partitioning at the Earth’s surface. variations, all datasets reveal similar Wetterdienst, Hydrometeorology, good global overview of the consistency Changing shares of latent and sensible patterns, but the absolute values vary Offenbach am Main, Germany and the quality of the modeled heat fluxes, caused by soil moisture between the different datasets. variations, can affect both near-surface air Precipitation is a difficult parameter for precipitation can be obtained by temperature and precipitation. Here, we use Eventually, the analysis allows to estimate reanalyses models, but it also has a means of correlation and contingency a simple framework for the dependence of the effect that soil moisture variations strong impact on our daily life. But since table scores. Climate change indices evaporative fraction (the ratio of latent heat have on near-surface air temperature. precipitation has not been assimilated (ETCCDI) for precipitation are calculated flux over net radiation) on soil moisture to While the different datasets agree well into the reanalyses, it is possible to to determine extreme values and their analyze spatial and temporal variations of on the magnitude (typical soil moisture assess the predicted precipitation temporal change (Peterson et al., 2001, land-atmosphere coupling and its effect variations can impact air temperature with independent observation. Both Appendix A). by several kelvin), there are apparent reanalysis, ERA-20C deterministic (Poli et on near-surface air temperature. For more detailed investigations daily differences in the patterns between the al., 2015) and the 10-member ensemble precipitation is clustered into events This framework allows to separate re-analyses and the combined dataset, CERA-20C (ECMWF, 2017) are yielded based on days with more than 1 mm water-limited from energy-limited especially in Africa and South America. from the projects ERA-Clim and ERA- evapotranspiration regimes and thus Clim2. precipitation. Here, only grid-points with to isolate the effect of soil moisture on The results emphasize the role of soil more than 250 events were considered to atmospheric conditionse estimate and moisture for atmosphere and climate and The multi-decadal reanalyses cover more have statistical sufficient quantity, which compare soil moisture-temperature highlight that a proper integration of these than one century from 1900 to 2010 excludes very dry area like Sahara or coupling strength using re-analysis data processes in weather and climate models and have a spatial resolution of about very wet areas like Indonesia. (ERA-Interim/Land, MERRA-2) on the is crucial. Important efforts have been 125 km. The reanalyzes are produced one hand and a dataset combination made in the recent years to create datasets by the ECMWF’s IFS forecast model, for a more thorough investigation of land- but for CERA-20C the IFS model for the

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 34 Section 4

Not surprisingly, the regions with the reanalysis ERA-20C. The local SST- the effects of data assimilation, model strongest differences are also those with precipitation relationships are an An intercomparison of the Arctic physics and atmospheric forcing on the data scarcity, mountain regions with indicator of air-sea interactions at sub- sea ice cover in global ocean- simulated Arctic sea ice concentration, their Luv and Lee effects or monsoon seasonal timescales in CERA-20C and sea ice reanalyses from the thickness and velocity. areas. They all show a strong systematic ERA-20C, and these are compared with project ORA-IP The comparison reveals an overall difference and breaks within the time observations using monthly data over agreement in the reconstructed series. Differences based on ETCCDI 1979-2010. Author Matthieu Chevallier concentration fields, mainly because diagnoses were detected particularly In convective regions, the negative Affiliation CNRM, Météo France of the constraints imposed by direct in regions with large precipitation totals SST-precipitation correlations in Co-authors assimilation of ocean and/or sea especially in Africa in the ITCZ area and observations are well captured in CERA- Matthieu Chevallier (CNRM, Météo ice observations and prescribed or in Indonesia. The overall comparison 20C, while these are not well reproduced France, Toulouse, France), Greg Smith assimilated atmospheric forcing. reveals geo-spatially heterogeneous in ERA-20C, which is more likely to (MRD, Environment Canada, Dorval, results with areas of similar precipitation A large spread in sea ice thickness is show positive correlations. It appears Canada), Frédéric Dupont (MSC, characteristics, but there are also still found within the ensemble of reanalyses, that in the coupled reanalysis ocean Environment Canada, Dorval, Canada), areas that present a challenge. partially caused by the biases inherited surface can cool down with less surface Jean-François Lemieux (CMC, from their sea ice model components. Additionally, areas with matching solar radiation associated with more Environment Canada, Dorval, Canada), Biases are also affected by the precipitation totals do not necessarily precipitating clouds. Magdalena Balmaseda (ECMWF, assimilation of sea ice concentration and show matching extreme value indices, or Reading, UK), Keith Haines (NCEO, However, in the uncoupled data, the the treatment of sea ice thickness in the even the indices show inconsistent results University of Reading, UK), Petteri Uotila prescribed SST does not respond to data assimilation process. The spatial depending on the region. (FMI, Finland), Hugues Goosse atmosphere feedbacks. Consequently, distribution of ice volume varies widely (Université de Louvain-la-Neuve, in the coupled reanalysis the mean between products, with no reanalysis Belgium), François Massonnet (Université precipitation is better estimated over standing out as clearly superior as Improved SST-precipitation de Louvain-la-Neuve, Belgium), Gilles most of the tropical and subtropical compared to altimetry estimates. relationships in the CERA-20C Garric (Mercator Océan, France), oceans, although it is worse over South coupled climate reanalysis Doroteaciro Iovino (CMCC, Italy), Frank The ice thickness from systems without America. We discuss the physical Kauker (AWI, Germany), the ORA-IP and assimilation of sea ice concentration Author Xiangbo Feng mechanisms controlling the SST- PORA-IP teams. is not worse than that from systems precipitation relationship at sub-seasonal Affiliation Department of constrained with sea ice observations. timescales and how this can also impact meteorology, University This presentation summarizes the Interannual variability of the distribution the longer-term variations and trends in of Reading evaluation of Arctic sea ice cover of thin/thick ice differs among the precipitation in the coupled product. Co-authors in global ocean-sea ice reanalyses reanalyses, which questions the Xiangbo Feng, Keith Haines, Chunlei conducted as part of the Clivar-GSOP/ suitability of current sea ice reanalyses LiuDepartment of Meteorology, University GODAE OceanView Ocean Reanalyses to initialize seasonal forecasts of the of Reading, Reading, UK Intercomparison Project (ORA-IP). Arctic sea ice. An evaluation of the sea Analyses have been conducted on a set ice velocity fields reveals that ice drifts ECMWF has recently produced the 20th of 14 global reanalyses, among which too fast in most systems, although the century ocean-atmosphere coupled 9 assimilated sea ice concentration reanalysis CERA-20C, following on data. Differences between the various from the similar uncoupled atmosphere reanalyses are explored in terms of

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 35 Section 4 interannual variability of average velocity ensemble reanalysis, both covering the Era-Interim and ERA5, MERRA2, CFS/ and Fram Strait ice export is reasonably satellite era. The scale of atmospheric 800+ site validation of Reanalysis CFSR and JRA55) and to map the well reproduced in all systems. features that can be represented by & downscaled wind conditions climate quality for wind industry end- a gridded reanalysis is limited by the users. A large databank of over 800 The simulated sea ice velocity seems time series resolution of the model grid and its site with windmast measurements was directly impacted by the choice of accuracy is dependent on observations, Author Gil Lizcano employed for the validation of modeled dynamical model parameters, which is model and boundary conditions, which Affiliation Vortex wind time series. The sites represent a not obvious for sea ice thickness. As all contain uncertainty. large spectrum of flow complexity across an ensemble, the ORA-IP reanalyses Co-authors different locations for most of the wind capture trends in Arctic sea ice area Activities to measure uncertainty in O. Lacave, Vortex, P. Casso, Vortex, industry target markets. and extent relatively well. However, reanalyses have often been limited by the A. Bosch, Vortext, A. Monternes, Vortex the ensemble can not be used to get lack of available independent measures In particular, time correlation, consistency Model data are employed at different a robust estimate of recent trends of the true state of the atmosphere, and bias and RMSE are provided for stages of the windfarm development: in the Arctic sea ice volume. Recent however such capability is highly different categories and locations. country engagement, resource developments within the Polar Ocean desirable in order to inform a diverse set Comparison between raw Reanalysis screening, site identification, preliminary Reanalyses Intercomparison Project of users on the suitability of the data. If data and 3km and 100m downscaled feasibility studies and due diligence (PORA-IP) will be mentioned, including uncertainty is not transparent to users, products will be presented to assess the process. Over the last 5 to 10 years, updates of the analysis on Arctic sea they may assume the reanalysis data is added value of the augmented resolution. Reanalysis and downscaled products ice with a more recent generation of certain or that the uncertainty does not have been adopted by the wind industry ocean reanalyses, and insights on the vary. as a feasible solution to complement representation of the Antarctic sea ice Do reanalyses capture long-term By perturbing sources of uncertainty, the on-site measurements and to fill the lack cover in global ocean reanalyses. changes in extreme weather UERRA ensemble reanalysis estimates of information demanded by a global statistics? the uncertainty in the ensemble mean. maked with project developments in Uncertainty in Reanalysis This capability will be evaluated to places as differents as North Chile, Author Prashant Sardeshmukh over Europe demonstrate how reanalysis uncertainty Anatolia complex mountains, North Sea Affiliation CIRES/University of varies with space, time and synoptic or Kenyan valleys. Colorado and Physical Author Peter Jermey condition. The impact of the changing This work provides an global wide insight Sciences Division/NOAA Affiliation Met Office observing system over forty years will on the quality of wind conditions virtual Co-authors also be demonstrated. Co-authors time series based on latest Reanalysis PD Sardeshmukh, GP Compo, A Wang, Peter Jermey, Richard Renshaw, database. More than 800 on site C McColl (all CIRES, University of Jemma Davie measurement time series were employed Colorado and Physical Sciences Division/ to obtain a complete understanding NOAA) The Uncertainties in Ensembles of of the performance of Reanalysis and Regional ReAnalyses (UERRA) project derived WRF downscaled output in the The ability of reanalyses to represent has produced regional reanalyses of the context of wind industry applications. long-term changes in the climate system is atmosphere over Europe. The principal often questioned, despite their advantages contributions of the Met Office (UK) to We intend with this presentation to of filtering out observational error and local the project are a 12km deterministic provide a comprehensive metrics of reanalysis and a 20 member 36km different Reanalysis projects (ECMWF

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 36 Section 4 noise at the observation locations and of This adds credence to both the extreme With ALERA and ALEDAS, several OSE generating physically consistent estimates changes inferred from the reanalyses studies have been conducted to assess of other variables at other locations. and the beneficial impact of even just impacts of radiosonde observations the surface pressure observations in obtained during some observational This is because these advantages are constraining those reanalyses. Similar campaigns, especially on the Arctic compromised by the sparseness and conclusions drawn from comparing and subtropical oceans. Recently we errors of the observations in the earlier changes in extreme daily precipitation have also performed some weather parts of the record, which cause the statistics over the shorter 1979-2012 predictability studies by using ALERA reanalyses to be more heavily influenced period will also be discussed. and/or the OSE reanalyses as initial by errors in the assimilating model’s values for AFES. In addition, a diagnostic guess fields, specified boundary technique called Ensemble Forecast conditions and radiative forcings. The AFES-LETKF data Sensitivity to Observations (EFSO) which The problem is relatively more serious for assimilation system for an can quantify how much each observation assessing changes in extreme weather experimental atmospheric global has improved or degraded the forecast statistics. We have addressed this issue ensemble reanalysis without a data denial experiment has by examining changes in the probabilities been recently implemented into ALEDAS. of extreme lower tropospheric 5-day Author Akira Yamazaki The preliminary results from EFSO will averaged temperature anomalies in five Affiliation Japan Agency for Marine- be compared against OSE. global reanalyses ranging in complexity Earth Science and from the low-resolution surface-input Technology (JAMSTEC) only 20th century reanalysis (20CR) to the Co-authors much higher-resolution full-input JRA55 Akira Yamazaki (Application Laboratory, reanalysis of the 1959-2012 period, JAMSTEC), Takeshi Enomoto (Disaster plus two large ensembles of model Prevention Research Institute, Kyoto simulations of the period generated using University), Takemasa Miyoshi (RIKEN the 20CR model with two different sets of Advanced Institute for Computational SST and sea-ice boundary conditions. Science), Nobumasa Komori (Application The changes in extreme temperatures from Laboratory, JAMSTEC) the first to the second half of the period A global atmospheric data assimilation agree well among the reanalyses, although system called ALEDAS comprised of AFES less well than the changes in mean (Atmospheric GCM for the Earth Simulator) temperatures. This is shown to be mostly and LETKF (Local Ensemble Transform due to disagreement in representing Kalman Filter) has been developed and changes in the temperature variance. The is used to generate the experimental model simulations capture the essence of atmospheric global ensemble reanalysis the extreme changes in most regions, but (ALERA) dataset available from January differ more from the reanalyses than the 2008 to January 2013, which has been reanalyses differ among themselves. prolonged toward near real time analysis.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 37 evaluation of the EEI as they deliver a 3-D During this talk, I will review the use of Section 5 – view on the interior of our oceans and Reanalyses’ use in operational reanalyses in the ECMWF operational Applications of its temporal changes from a combined weather forecasting production process. use of ocean observing systems and reanalyses numerical model techniques. Author Roberto Buizza Affiliation ECMWF Stratospheric intrusion- Moreover, ocean reanalysis systems Insights into the role of the Co-authors influenced ozone air quality deliver us a unique insight into the role exceedences investigated in the oceans in the Earth energy of the oceans as energetic buffer and Roberto Buizza (ECMWF) NASA MERRA-2 Reanalysis budget from ocean reanalysis regulator through its capacity to absorb In the past two decades we have and to redistribute large amounts of heat. Author Karina von Schuckmann seen an increased use of reanalysis Author Katherine Emma In addition, consistency checks through Affiliation Mercator Ocean in operational weather forecasting. Affiliation Knowland Universities physical budget constraints with the Reanalyses provide initial conditions for Space Research Co-authors combined use of climate observations reforecasts, i.e. forecasts re-run using Association (USRA) Karina von Schuckmann (Mercator (in situ, remote sensing) and tools operational systems for past cases, both Ocean, France) Co-authors (reanalysis, climate models) have a large to improve operational forecast products potential to deliver a robust uncertainty KE Knowland (USRA/GESTAR; NASA/ Improving the accuracy of estimates of and to provide users with a more Global Modeling and Assimilation Office assessment, to shed new light on solid performance assessment of the Earth’s climate state and variability is unresolved climate science issues and (GMAO), GSFC, Greenbelt, MD), LE Ott critical for advancing our understanding accuracy and reliability of the operational (NASA/GMAO, GSFC, Greenbelt, MD), to strengthen the exchange between forecasts. Examples of operational and prediction of the evolution of Earth’s multi-disciplinary experts all concerned BN Duncan (Laboratory for Atmospheric climate. The energy budget of the products generated using reforecasts are Chemistry and Physics, GSFC, Greenbelt, with the energy flow through the climate the ECMWF Extreme Forecast Indices for Earth is a key determinant for the state system. MD), Krzysztof Wargan (Science Systems and evolution of climate on our planet. 2-meter temperature and precipitation. & Applications, Inc. (SSAI); NASA/GMAO, Perturbations of this budget from internal This talk will give an overview on the They are defined by comparing the GSFC, Greenbelt, MD) or external climate variations create a development of ocean climate indicators probability distribution function of forecast Ozone near the surface is harmful radiative flux imbalance at the top of the such as EEI from ocean reanalyses, their states computed using the most recent to human health and is a result of atmosphere. use for physical budget constraints, ECMWF ensemble of forecasts, and photochemical reactions with both man- and the evaluation on the redistribution the model climatological distribution This Earth Energy Imbalance (EEI) is made and natural precursor pollutant of ocean heat. Specific examples will function computed using an ensemble of shaped by several climate forcings, some sources. Therefore, in order to reduce be introduced and main outcomes and reforecasts initialized using reanalyses for of which occur naturally and some that near surface ozone concentrations, challenges are discussed. the past 20 years. are anthropogenic in origin. There is communities must reduce anthropogenic a current positive EEI, which is mostly Examples of performance estimation pollution sources. caused by human activity, and which is based on reforecasts initialized from However, the injection of stratospheric driving global warming. The EEI can best reanalyses are the reliability diagrams of ozone into the troposphere, known be estimated from changes in ocean the ECMWF seasonal ensemble forecasts as a stratospheric intrusion, can also heat content, complemented by radiation of sea-surface temperature anomalies in lead to concentrations of ground-level measurements from space. Ocean a set of tropical regions, e.g. covering the ozone exceeding air quality standards. reanalysis systems are critical for the El Niño areas in the tropical Pacific Ocean. Stratospheric intrusions are dynamical

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 38 Section 5 atmospheric features, however, these Extreme precipitation events in the These techniques are employed summer monsoon rainfall (June through intrusions have been misrepresented in United States can be caused by various for extreme precipitation events in September: ISMR; Amita et.al. 2016), the models and reanalyses until recently, meteorological influences such as preselected regions that were chosen May-June SAM has a significant positive as the features of a stratospheric extratropical cyclones, tropical cyclones, based an analysis of the climatology of relation with the summer monsoon intrusion are best identified in horizontal mesoscale convective complexes, precipitation. rainfall over the South Korea-Japan resolutions of 50 km or smaller. general air mass thunderstorms, upslope peninsula (June through August: JJA, flow, fronts, and the North American Amita et.al 2017). Monsoon. Reanalyses, such as the Role of Southern Annular Mode Delayed response over South as well Classification of Meteorological Modern Era Retrospective Analysis for on Asian Monsoon: Mechanisms as over East Asia is relayed through the Influences Surrounding Extreme Research and Applications, version 2 through NCEP-NCAR Reanalysis central Pacific sea surface temperatures. Precipitation Events in the (MERRA-2), have become a pivotal tool Author Amita Prabhu A negative (positive) phase of SAM to study the meteorology surrounding United States using the generates a wave-train which propagates extreme precipitation events. Using days Affiliation Indian Institute of Tropical MERRA-2 Reanalysis from the sub-polar latitudes towards classified as an extreme precipitation Meteorology the equatorial latitudes associated Author Allison Collow events based on a combination of Co-authors with warming (cooling) over the central Universities Space observational gauge and radar data, two R. H. Kripalani (Indian Institute of Tropical Affiliation equatorial Pacific region. Research Association techniques for the classification of these Meteorology), G. Pandithurai ((Indian Co-authors events are used to gather additional Institute of Tropical Meteorology) This warming (cooling) induces an A. Collow (USRA/NASA GSFC), M. information that can be used to determine ascending (descending) motion over The annular modes are the most Bosilovich (NASA GSFC), and P. Ullrich how events have changed over time using the central Pacific with descending important hemispheric scale patterns (UC Davis) atmospheric data from MERRA-2. (ascending) motion over the (i) Indian of climate variability in the northern and subcontinent through the zonal Walker The first is self organizing maps, which Extreme precipitation events can have a the southern hemisphere. The Southern circulation influencing the ISMR; is an artificial neural network that uses large impact on society through flooding Annular Mode (SAM) is characterized by (ii) Korea-Japan sector through the unsupervised learning to cluster like that can result in property destruction, a see-saw phenomenon between the sea meridional Hadley circulation influencing patterns and the second is an automated crop losses, economic losses, the spread level high pressure belt normally across the peak July-August monsoon over detection technique that searches for of water-borne diseases, and fatalities. ~400S and a low pressure belt across Korea-Japan. These findings have characteristics in the atmosphere that Observations indicate there has been ~700S. SAM is also referred as a High- potential implications on the seasonal define a meteorological phenomena. For a statistically significant increase in latitude Mode or the Antarctic Oscillation. forecasts of both the South and East example, the automated detection for extreme precipitation events over the SAM index is defined as MSLP 400S – Asian summer monsoons. tropical cycles searches for a defined past 15 years in the Northeastern United MSLP 700S. area of suppressed sea level pressure, States and other localized regions of alongside thickness anomalies aloft, Based on the National Centers for the country have become crippled with indicating the presence of a warm core. Environmental Prediction and National record flooding events, for example, the Center for Atmospheric Research flooding that occurred in the Southeast (NCEP/NCAR) Reanalysis data spanning United States associated with Hurricane 31 years for the period 1983-2013, Matthew in October 2016. results reveal that while the February- March SAM has a significant positive relation with the subsequent Indian

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 39 Section 5

Total MAHT of latent heat correlates percentiles. Strong seasonal and spatial Arctic warming from calculations in winter months only. To understand Intercomparison of the near- variability have been identified with an on base ERA/Interim the lack of correlation we construct the surface wind speed trends in increase of the wind speed over the distribution of spatial anomalies monthly three reanalyses ocean and a decline over land, although Author Aleksandra Urazgildeeva mean air temperature and water vapor disagreement between the reanalyses Affiliation Arctic and Antarctic content at isobaric surfaces averaged Author Verónica Torralba has been identified, particularly for the Research Institute – AARI for 1979-2014, which show two regions Affiliation Barcelona JRA-55 reanalysis which overestimates Co-authors with maximal anomalies. These regions Supercomputing Center the trends over land. The causes of A. Urazgildeeva (AARI), G. Alekseev corresponded to parts of 70°N circle Co-authors these wind speed trends are discussed (AARI), S. Kuzmina (Nansen Center), across which the heat and moisture enter V. Torralba (Barcelona Supercomputing in terms of the wind speed at 850 hPa, L. Bobylev (Nansen Center). 70-90°N area. Center (BSC)), F. J. Doblas-Reyes because although changes in land use, (Barcelona Supercomputing Center aerosols and the recent modifications The objective of our investigation is to We referred both parts as to Atlantic (BSC), Institució Catalana de Recerca i of the large-scale circulation have been establish the link between amplified (0-80°E) and Pacific (200-230E) “gates”. Estudis Avançats (ICREA)), N. Gonzalez- identified to play a role over wind speed winter warming in the high Arctic and Further, we estimated and analyzed Reviriego (Barcelona Supercomputing trends, it is still not fully understood how meridional atmospheric heat transport MAHT across these “gates” for sensible Center (BSC)) L. Lledó (Barcelona these factors could affect wind speed (MAHT) across the 70° N. Data from (JT) and latent (JQ) heat fluxes across Supercomputing Center (BSC)), R. trends at global scale. ERA/Interim (Dee et al., 2011) for the unit normal area at every isobaric Marcos (Barcelona Supercomputing 1979-2014 were used. Data included surface. Winter MAHTs across 70°N Center (BSC)), N. Cortesi (Barcelona monthly air temperature, water vapor into the Arctic take place up to 750 hPa On requirements for the Supercomputing Center (BSC)) and A. content, meridional component of the and mainly through Atlantic “gate”. Its application of reanalyses in the Soret (Barcelona Supercomputing Center wind at grid points 1°×1° from 1000 to show a positive trend, 5-7 years cyclicity (BSC)) context of climate monitoring and 100 hPa spaced-apart 50 hPa. and correlate with mean surface air temperature (SAT) in 70-90°N area. energy applications in Germany Wind energy users have recently Total values of meridional transport of MAHTs across Atlantic “gate” influence incorporated reanalyses products for the Author Frank Kaspar heat and moisture through a unit vertical on winter SAT at the most part of 70- evaluation of the long-term wind speed Affiliation Deutscher Wetterdienst from the surface to 10 hPa and integral 90°N area with maximum at the Barents variability, particularly in those regions from the surface to 10 hPa water vapor and Kara Seas. The same correlation Co-authors where there are not long observational content in each grid point were used pattern results from ECHAM model F. Kaspar (Deutscher Wetterdienst), A. K. records available. This study explores the also. Calculations of MAHT into 70°-90°N control experiment data in SMIP5. Kaiser-Weiss (Deutscher Wetterdienst), area were fulfilled on base (Nakamura, wind speed long-term trends at global M. Borsche (Deutscher Wetterdienst) Oort, 1988) formulas. Total MAHT scale in the last decades (1980-2015) Germany’s meteorological service of sensible heat across 70°N “wall” using three reanalyses: ERA-Interim, (Deutscher Wetterdienst) is responsible to calculated from vertically integrated Japanese 55-year Reanalysis (JRA- provide regular statements on climate and values of MAHT in every grid point in 55) and Modern Era Retrospective- climate change in Germany. Traditionally, ERA/Interim area is uncorrelated with Analysis for Research and Applications these statements are based on the long mean air temperature in 70- 90°N area in (MERRA-2). time series of meteorological observations every months. The intercomparison focuses on the taken at conventional statements. seasonal variability of the mean wind speed but also the 10th and 90th

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 40 Section 5

For example, time series of temperature presentation, a summary of our recent A downscaling at 5.5km is performed to The research leading to these results and precipitation are available at experience of these user requirements derive wind and the downwards radiative has received funding from the European sufficiently high spatial density since will be given. fluxes, and to provide background fields Union, Seventh Framework Programme 1881 and can be used to derive monthly for the MESCAN surface analysis of (FP7-SPACE-2013-1) under grant The Work Package on Evaluation in maps of these parameters which are 2m temperature and relative humidity agreement no 607193. the European FP7-Project UERRA used to provide monthly updates on and 24h accumulated precipitation. (“Uncertainties in Ensembles of Regional the state of climate in Germany to the These mesoscale fields are then used ReAnalyses”) is focusing on the evaluation public (see e.g. http://www.deutscher- to drive hydro-meteorological off-line Development of long-term hydro- of user-relevant parameters and provides klimaatlas.de). However, in recent years simulations based on the coupled meteorological reconstructions results for selected requirements from the new requirements for improved climate SURFEX-CTRIP system, where SURFEX over France based on large scale renewable energy sector. monitoring products came up, which is the land surface model developed atmospheric reanalyses to study cannot be fulfilled with such a traditional and used at Meteo-France for NWP the multi-decadal variability of approach. On the use of the 50-year high- and climate applications, and CTRIP is French river flows the river routing model used for climate One important example are wind resolution UERRA re-analysis applications at Meteo-France. Author Rémy Bonnet conditions at different height levels, over for a hydro-meteorological land but also over the North and the application over Europe Such a system provides not only Affiliation Cerfacs Baltic Sea. At these locations and heights, ECVs, such as soil moisture, snow Co-authors no long series with direct observations Author Patrick LE MOIGNE depth, etc., but also computes the R. Bonnet (CECI-CERFACS), J. Boé are available. In addition to that wind Affiliation Meteo-France various components of the water (CECI-CERFACS), G.Dayon (CECI- measurements from conventional stations Co-authors cycle: precipitation, surface runoff, soil CERFACS) might be affected by inhomogeneities. P. Le Moigne (Meteo-France), C. infiltration and water storage, as well as Recent studies based on the few Improved climatologies are not only Szczypta (Meteo-France), A. Verrelle the time evolution of rivers discharge available long-term observations show requested by the commercial sectors, (Meteo-France), E. Bazile (Meteo-France), and aquifers height. A description of the a large multidecadal variability in but are also needed for assessments R. Abida (Meteo-France) MESCAN-SURFEX-CTRIP system will of different government agencies, e.g. be done first. A detailed analysis of the French river flows. Understanding the for continuously assessing the progress The UERRA project is a 4-year project water cycle components climatology over mechanisms behind this variability is a in the transition of the energy sector or (2014-2017) financed by the European the 50-year period over Europe will be challenging issue, given the limitation of providing basic information for longer- Union under its 7th Framework done and comparisons with independent observed data-sets. The recent release term decisions in the energy sector. Programme SPACE. One of its main observations of river discharges and of two extended large-scale atmospheric objectives was to build a high resolution snow depths will be discussed. reanalyses (NOAA 20CR and ECMWF Regional reanalysis has the potential (5.5km) 50-year reanalysis of surface ERA20C) has opened great opportunities to provide the required products, but a essential climate variables (ECV) over Uncertainties will also be discussed in that context. quality assessment of these products is based on simulations of a MESCAN- Europe, together with uncertainty They can be downscaled, here with a a prerequisite. The applications therefore estimates. The atmospheric UERRA SURFEX-CTRIP 8-member ensemble have implications on the requirements covering the 2006-2010 period. Additional statistical downscaling method already reanalysis relies on the HARMONIE used in a climate change study, to for uncertainty estimates and timeliness system and the ALADIN model at 11km information about the UERRA project can of the reanalysis products. In the be found at http://www.uerra.eu obtain the long-term high resolution horizontal resolution. meteorological forcing needed for hydrological modelling. A limitation of

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 41 Section 5 this approach is that the reconstructions as predictors: daily precipitation and strongly depend on the quality of the From data mining to information its rolling sum, snow depth and its Mediterranean Sea circulation reanalyses and some studies highlighted extraction: using ERA-INTERIM rolling sum, the first three modes of in high-resolution hindcast potential unrealistic long-term trends or reanalysis to model hydro-power geopotential height at European level. We simulations and reanalyses artificial temporal variations in long-term production in Europe have used three distinct values for the reanalyses. “width” of the rolling sum: five days, 30 Author Gianmaria Sannino Author Matteo De Felice days and the value which maximise the Affiliation ENEA In this study, we first assess the low- correlation with the generation data. frequency variations of precipitation and Affiliation ENEA Co-authors temperature over France in the long- Co-authors Four different models have been used G.Sannino (ENEA), A. Bargagli (ENEA), term atmospheric reanalyses. Then, M. De Felice (ENEA), L. Dubus (EDF), to model the daily generation of hydro- A. Carillo (ENEA), A. Dell’Aquila (ENEA), a new statistical approach based on A. Troccoli (University of East Anglia) power: linear-regression model, a R. Iacono (ENEA), E. Napolitano (ENEA), the results of a statistical downscaling regression tree, an ensemble of model G.Pisacane (ENEA), M.V. Struglia (ENEA), method applied to the reanalyses The installed capacity of renewable trees and Random Forests. Using a J.Beuvier (Mercator Ocean) and constrained by available long- energy sources (RES) is steadily cross-validation procedure, all the Recent atmospheric reanalysis products, term homogenized precipitation and increasing in European countries. For an combinations of models, countries such as ERA40 and ERA-Interim, and temperature observations over France is efficient integration and management is and generation type have been tested, their regional dynamical downscalings, presented. important to be able to explicate the link summarising the results using ranked prompted the scientific community between the meteorological variables correlation. The modelling performance The reconstructed meteorological forcing to perform hindcast simulations of and the generation of electricity. To this for run-of-river is higher than the other and in particular the low-frequency the Mediterranean Sea, giving us the end, several approaches can be used, two categories: correlation is above variations are evaluated. The river opportunity to evaluate the response of including data-driven methods (statistical 0.9 for France, Germany, Romania and flows obtained with an hydrological ocean models to a realistic interannual models, machine-learning). Norway. model forced by the reconstructed air-sea fluxes atmospheric forcing. meteorological forcing are also compared To successfully build a data-driven model More surprisingly, the correlation is above On the other hand, ocean reanalysis to the few available long-term observed it is fundamental the availability of high- 0.7 also for water reservoir generation for products represent an interesting series. The added value of constraining quality data sets of observed data, i.e. countries like France, Germany, Portugal, reference dataset for the evaluation of the results of statistical downscaling generated electricity and meteorologica Norway, Spain and Sweden. We can these hindcast simulations. with homogenized observations is then predictors for hydro-power modelling. conclude that meteorological predictors, The objective of this work is to present discussed. The interest of our approach Hydro-power generation data has such as those from the ERA-INTERIM a comparison of two recent hindcast to study the multidecadal variations in been obtained from the ENTSO-E reanalysis, used as input to a purely simulations of the Mediterranean Sea different variables of the continental Transparency Portal, divided in three statistical approach as that proposed Circulation, performed at 1/12° horizontal hydrological cycle over France is finally categories (run-of-river, water reservoir in this work, are effective at modelling, resolution with different ocean models highlighted. and pumped storage) and available for and potentially predicting, hydro-power (MITgcm and NemoMed). The simulations all the ENTSO-E countries since January generation at country scale. 2015. share the same atmospheric forcing obtained by a downscaling of the ERA- Meteorological data has been obtained Interim atmospheric reanalysis performed from ECMWF ERA-INTERIM reanalysis. by the Regional Climate Model ALADIN- The following variables (averaged at Climate (ALDERA). country-level) have been considered

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 42 Section 5

The circulation and hydrological are identified in MERRA-2 by the folding impact on the ocean variability over a baroclinic contribution from density stratification are compared with the of the dynamical tropopause under the wide range of features that could not be gradient as well as several different results of two different ocean reanalyses: jet stream and subsequent isentropic well reproduced otherwise. processes. MEDRYS and MFS, the latter being descent of dry, ozone-rich stratospheric They can largely affect the estimate Further to assessing the eddy statistics the ocean reanalysis performed for the air towards the surface near the location of lateral turbulent fluxes of heat and from three different datasets, a global 3D Mediterranean Sea within the framework of the observed ozone air quality tracers together with vertical exchange eddy detection system is implemented of the Copernicus Marine Environment exceedences. processes, typically occurring mostly in order to bypass the need of regional- Monitoring Service (CMEMS). In The MERRA-2 reanalysis can at wavelengths less than 100km. In this dependent definition of thresholds. It particular MEDRYS have been performed support air quality agencies for more work, we focus on the role of assimilative thus provides full three dimensional eddy with the same configuration of the rapid identification of the impact of schemes in enhancing the three- structures segmenting vertical profiles NemoMed model and use the same stratospheric air on surface ozone and dimensional variability by comparing the from local rotational velocities. This forcing of the hindcast simulations. demonstrates that future operational 3D eddy content and energetics among criterion is crucial for discerning real The availability of long time-series of analyses may aid in forecasting such three different datasets: a global ocean eddies from transient surface noise. Our Essential Climate Variables from ccean events. reanalysis (C-GLORS), a free global analysis shows that the latter impacts for reanalyses is important for the validation ocean simulation (NEMO system) and an about the 10% of eddy population. of the hindcast run of climate models, observation-based dataset (ARMOR3D) which is mandatory in view of the use A three-dimensional used as an independent benchmark. of climate models for future scenario characterization of eddy Downscaling ERA-5 reanalysis projections. activities in a global ocean Datasets are at 1/4 horizontal resolution data for coastal climate and cover a 10-year period. While the NASA’s Modern-Era Retrospective applications and evaluation of eddy-permitting reanalysis free simulation fairly reproduces eddies Analysis for Research and Applications emerging from western boundary uncertainty of coastal data Version-2 (MERRA-2) reanalysis is a Author Andrea Cipollone currents and deep baroclinic instabilities, publicly-available high-resolution dataset Affiliation CMCC Author Carlo Brandini it underestimates shallower vortexes. The (~50 km), with assimilated satellite Affiliation CNR Ibimet – Consorzio Co-authors ocean Reanalysis recovers most of the retrievals of ozone, that characterizes LaMMA A. Cipollone (CMCC), S. Masina missing turbulence that is not generated stratospheric and upper-tropospheric (CMCC, INGV), A. Storto (CMCC), by the model itself and consistently Co-authors ozone on the same spatiotemporal D. Iovino (CMCC) projects surface variability through the Carlo Brandini (CNR-Ibimet & Consorzio resolution as the meteorology. We find full water column. LaMMA), Valerio Capecchi (CNR-Ibimet & stratospheric intrusions which impact Ocean Reanalyses, at eddy-permitting Consorzio LaMMA), Francesco Pasi surface air quality are well represented in resolution, have nowadays reached a Eddies are responsible for more than (CNR-Ibimet & Consorzio LaMMA), the MERRA-2 reanalysis. satisfactory degree of accuracy that 60% of total EKE in regions where deep Stefano Taddei (Consorzio LaMMA), allows for first investigations about the baroclinic instabilities occur and where This is demonstrated through a case Alberto Ortolani (CNR-Ibimet & contribution of mesoscale variability eddy cores are shown to be located well- study analysis of stratospheric intrusion Consorzio LaMMA), Bernardo Gozzini to the ocean dynamic and energetics. below the ocean surface. Eddy thickness events which were identified by the (Consorzio LaMMA). Thanks to the new high-resolution is also compared, ARMOR3D shows United States Environmental Protection satellite products, data assimilation much deeper eddies compared to the The management of coastal zones Agency (EPA) to contribute to elevated procedures can have a remarkable Reanalysis dataset where deep currents requires precise data concerning past ground-level ozone in spring 2012 in are consistently generated by the model wind/wave regimes and future climate Colorado. The stratospheric intrusions primitive equations thus embedding trends. Many studies have been based

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 43 Section 5 on low resolution reanalysis data that Global high-resolution simulation cannot allow a detailed description of the A roadmap to Earth surface capacity can benefit enormously next variability induced by local conditions. kilometre-scale simulations generation reanalyses products when We present a feasibility study where a combined with refinements in the simple dynamical downscaling of ERA Author Gianpaolo Balsamo treatment of physical processes to 5 reanalysis data is applied through a Affiliation ECMWF better account for regional and local cascade of regional atmospheric/wave Co-authors meteorological/climate/human-induced models. A long-term goal of this study is G. Balsamo, G. Arduini, A. Beljaars, changes. to identify the long-term trends in the last S. Boussetta, M. Choulga, E. Dutra, This presentation will cover current 30-35 years in order to better understand H. Herschbach, J. Munoz-Sabater, P. de efforts to characterise the Earth surface the effects linked to the impact of climate Rosnay, I. Sandu, N. Wedi at kilometre-scale making use of recent change along the coast. The strive to produce increasingly more remote-sensing dataset in collaboration The methodology applied is based on:- a accurate forecasts has pushed horizontal with the Copernicus Services and it will high resolution atmospheric model (WRF- resolutions of global Earth System illustrate some of the challenges with the ARW), run at a horizontal resolution of Models (ESM) to break into single-digit internal consistency across datasets and about 3 km;- a finite element wave model kilometre-scale (e.g. 9 km for global with their use in long reanalysis. (WW3), able to compute high-resolution HRES forecasts at ECMWF with a vision waves along the coast, at a resolution to increase it further towards 2025), up to 300-400 meters. Our target area while many National Meteo-Hydrological is the North-Western Mediterranean, Services already run at 1-2 km resolution characterized by a marked variability in on wide regional domains. At about wind/wave regimes. 1km there is close to a billion grid points The evaluation period is 3 months covering the Earth surface involving the and the quality assessment has been use of High Performance Computing to performed by using regional observed be timely simulated. data (coastal buoys and anemometers). However, there are not only computing Results show that regional downscaled and software challenges involved, data provide lower errors in the mean as accuracy requires to be able to wave parameters and wind regimes characterise the surface ancillary with respect to global data and some conditions at those resolution (vegetation significative improvements with respect and soil, water-land-snow-ice fractions, to studies based on past reanalysis data. and any meteorologically relevant Moreover we present results concerning properties) therefore involving satellite the use of the multiple members of the remote sensing observations and ERA5 data to improve the downscaled optimisation/inversion algorithms to information. estimate non-observable quantities.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 44 Posters

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 45 provide the background fields at 5.5km a modern reanalysis to replace the The accuracy was better near regions Section 1 – Status for the surface analysis (T2m, Rh2m, RR) venerable NCEP/NCAR Reanalysis (R1). with more observations such as the and plans of and to downscale the downward radiative This new reanalysis would be between Northern Hemisphere and closer to the fluxes and the wind at 5.5km required to these two extremes. surface. We did not find artifacts related reanalysis drive SURFEX with the T2m, Rh2m and to the introduction of new satellites as The accuracy would have to be similar precipitation analysis. CORe did not assimilate radiances from productions or better then R1 without the gross the satellites. However, we did encounter artifacts from the introduction of some other discontinuity issues that may the various satellites. The reanalysis A 50 year surface analysis over A Conventional Enkf be related to stream boundaries and to would also have to span the 1950’s Europe at 5.5km within the atmospheric REanalysis (CORe) the prescribed SST analyses. We will to the present. Towards this goal, we UERRA project show comparisons with other reanalyses. Author Wesley Ebisuzaki considered whether improvements in Author Eric Bazile Affiliation CPC/NWS/NOAA data assimilation and modeling would Affiliation Meteo-France/CNRS Co-authors allow a modern system that assimilated A New Version of Regional conventional observations to have Co-authors W. Ebisuzaki (NOAA-CPC), A. Kumar Ocean Reanalysis for Coastal similar or better accuracy than the old E. Bazile, R. Abida, C. Szczypta, (NOAA-CPC), J. Whitaker (NOAA-PSD), Waters of China and Adjacent R1 which assimilated satellite data using A. Verrelle, P. Le Moigne, C. Soci (1) J. Woollen (NOAA-EMC), H-C Lee vertical temperature retrievals. We ran Seas (Meteo-France/ CNRS) (1) ECMWF (NOAA-CPC), L. Zhang (NOAA-CPC) an experimental reanalysis using an Author Wei Li Ensemble Kalman Filter, atmospheric The UERRA project is a 4-year project Atmospheric reanalyses can be Affiliation Harbin Engineering (2014-2017) financed by the European optimized to produce the most accurate data assimilation system (Jeff Whitaker, University Union under its 7th Framework analyses by assimilating all observations Climate Diagnostics and Predication Co-authors Programme SPACE. One of its main including satellite observations. However, Workshop, Orono, Maine, 2016). This Wei Li (Harbin Engineering University) objectives is to provide a 50-year this type of reanalysis often shows system used a T254 64 vertical-level Xuefeng Zhang (Harbin Engineering reanalysis dataset of surface Essential discontinuities in various time series semi-Lagrangian version of the GFS University)Guijun Han (Harbin Climate Variables (ECV) at 5.5km grid at with the introduction of new satellite (Global Forecast System) model. Engineering University) systems. An atmospheric reanalysis can European scale, together with, as much The system assimilated conventional also be optimized for a more consistent as possible, uncertainty estimates. observations, cloud-track winds and A new regional ocean reanalysis over time series by limiting the observations GPS-RO (COSMIC data). The last multiple decades (1958 to 2008) for the The system used to provide the ECV to a more temporally consistent set of two items use satellite data but are coastal waters of China and adjacent and consistent other surface variables observations. at 5.5km such as soil moisture at relatively insensitive to the biases in the seas has been completed by the National several levels, surface evaporation, This was the approach used by the radiance measurements. We created an Marine Data and Information Service snow depth is based on a surface 20th Century Reanalysis (Campo et al experimental reanalysis that spans 1950 (NMDIS) under the CORA (China Ocean analysis (MESCAN) for 24h accumulated 2011) which only assimilated the surface to 2010. Using ERA-interim as a proxy for ReAnalysis) project. Evaluations have been precipitation (RR), 2m temperature pressure observations. The trade off truth, we found that the CORe reanalysis performed on the improvement of general (T2m) and relative humidity (rh2m) and for the consistency was a less accurate was usually closer to ERA-interim than reanalysis quality and eddy structures. on the surface platform called SURFEX. reanalysis because fewer observations R1 suggesting CORe met the accuracy Results show that the quality of the new The atmospheric re-analysis done by were assimilated. The Climate Prediction requirement in the troposphere and lower reanalysis is enhanced beyond ~40% SMHI with the HARMONIE system and Center (CPC, NWS/NOAA) requires stratosphere. (39% for temperature, 44% for salinity) the ALADIN model at 11Km is used to

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 46 Section 1 in terms of the reduction of root mean These measurements are further quality Centre for Weather Research, University squared errors for which the reanalysis Aerosols in MERRA-2 and Plans controlled using an adaptive buddy of Bonn), S. Crewell (Hans-Ertel-Centre values are compared to the observed for Aerosols in Future GMAO check scheme, and assimilated using for Weather Research, Unversity of values in the observational space. Reanalyses the Local Displacement Ensemble (LDE) Cologne) methodology. Compared to the old version, the new Author Arlindo da Silva The COSMO model (Consortium reanalysis is able to reproduce more We will present a summary of our efforts Affiliation NASA/Goddard Space for Small-scale Modeling) is a non- detailed eddy structures as seen in to validate the MERRA-2 aerosols. Flight Center hydrostatic limited-area atmospheric satellite and in-situ observations. These The GEOS-5 assimilated aerosol fields model, that is used for operational and Co-authors evaluations suggest that the new CORA are first validated by comparison to for research applications by Germany’s A.M. da Silva (NASA/GSFC), V. Buchard regional reanalysis creates a much more independent in-situ measurements Meteorological Service (Deutscher (NASA/GSFC, USRA), C. Randles (Exxon useful dataset for the community of the (PM2.5 concentrations, long term surface Wetterdienst, DWD) and other members Mobile), A. Darmenov (NASA/GSFC) coastal waters of China and adjacent seas. dust concentrations, Maritime Aerosol of the consortium (see http://www. Network, airborne and ground based After a brief description of the system MERRA-2 is NASA’s latest reanalysis cosmo-model.org/). lidars, UV based measurements, etc.) used for the surface analysis (MESCAN) for the satellite era (1980-present) using We will conclude with a discussion of The model was also used to generate a with a focus on the precipitation analysis Version 5 of thr GEOS Earth System our plans to extend the historical aerosol set of regional reanalysis datasets within (Soci et al. 2016) which is one of the model. This project focuses on historical observing system in future GMAO two activities: (1) A 6km deterministic most essential variable for several analyses of the hydrological cycle on a reanalyses. reanalysis for the European CORDEX- applications: hydrological model for water broad range of weather and climate time domain and a 2 km reanalysis for Central management or snow pack evolution over scales, and includes interactive aerosols Europe was produced within the Hans- mountains. We will present the results for the entire period. As another step An overview on regional Ertel-Centre for Weather Research for the 50 year period and preliminary towards an integrated Earth System reanalysis activities based on (HErZ). The HErZ branch on climate comparisons with independent Analysis (IESA), MERRA-2 includes for the COSMO model monitoring is a research group located observations and global re-analysis such the first time aerosols in a reanalysis at University of Bonn and University of as ERA40 and/or ERA-Interim. for the satellite era, improves the Author Frank Kaspar Cologne, funded by DWD. The aim is representation of stratospheric ozone, The evolution of the observation density Affiliation Deutscher Wetterdienst to analyze the potential of the regional and better characterizes cryospheric network and its impact on the long term Co-authors reanalysis system as a tool for climate processes. In this talk we will present series will be discussed. Additional F. Kaspar (Deutscher Wetterdienst), S. monitoring of DWD. (2) Within the EU- results relating to the introduction of information about the UERRA project Wahl (Hans-Ertel-Centre for Weather funded project UERRA an approach for aerosols in MERRA-2. can be found at http://www.uerra.eu Research, University of Bonn), J. Keller an COSMO ensemble reanalysis was The research leading to these results The assimilation of Aerosol Optical Depth (Hans-Ertel-Centre for Weather developed. has received funding from the European (AOD) in GEOS-5 involves very careful Research, University of Bonn, Deutscher Within that project, a dataset with 12 km Union, Seventh Framework Programme cloud screening and homogenization Wetterdienst), M. Borsche (Deutscher resolution is currently produced and will (FP7-SPACE-2013-1) under grant of the observing system by means of Wetterdienst), M. Lockhoff (Hans-Ertel- be compared to regional reanalyses of agreement no 607193. a Neural Net scheme that translates Centre for Weather Research, University other European partners. Both activities MODIS and AVHRR radiances into of Bonn), A. K. Kaiser-Weiss (Deutscher have a strong focus on the evaluation AERONET calibrated AOD. The system Wetterdienst), D. Niermann (Deutscher of the datasets. There is strong interest also assimilates MISR and AERONET Wetterdienst), A. Hense (Hans-Ertel- in the datasets from various sectors, AOD observations.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 47 Section 1 especially the energy sector. Therefore, new product that is consistent with the which suggests the CORA reanalysis one focus of the evaluation activities are forecast model used (Climate Forecast Development and Future Plan creates a much more useful dataset to parameters that are relevant for such System version 2). of the Global Ocean Reanalysis understand the physical relationship applications. between the different oceanic variables To develop this new product, in the China Ocean Reanalysis and the mechanisms of the evolution In this presentation we will provide an experiments have been conducted (CORA) Project of oceanic circulation in different time- overview of the reanalysis system, the with the Geophysical Fluid Dynamics Author Xuefeng Zhang space scales. datasets, evaluation results with focus Laboratory Modular Ocean Model on the user-relevant parameters and version 5 (MOM5). Here we will present Affiliation National Marine Data and Future plan of the global ocean reanalysis ongoing activities. Further details on results from these experiments, Information Service in CORA project is also be discussed specific evaluation activities will be highlighting the impacts of using different Co-authors further. addressed in separate presentations. surface boundary conditions, namely Xuefeng Zhang(National Marine Data and from the Climate Forecast System Information Service), Wei Li(National Reanalysis (CFSR) and Modern-Era Marine Data and Information Service), ECCO-Sea Level: The next phase Creating a sea ice reanalysis Retrospective analysis for Research and Guijun Han(National Marine Data and in the “Estimating the Circulation using an ocean model forced by Applications, version 2 (MERRA2). Information Service), Hongli Fu(National and Climate of the Ocean” Project surface fields from atmospheric Marine Data and Information Service), Also shown will be the impacts of using Author Ichiro Fukumori Xiaoshuang Zhang(National Marine Data reanalyses different vertical resolutions for the top and Information Service) ,Lianxin Affiliation JPL/Caltech layer of the ocean (10m and 1m), as well Author Thomas Collow Zhang(National Marine Data and Co-authors as the impacts of different sea surface Affiliation INNOVIM, LLC/NOAA Information Service) , Dong Li(National I. Fukumori (JPL/Caltech), P. Heimbach temperature restoring datasets, including Climate Prediction Center Marine Data and Information Service), (Univ. Texas Austin), C. Hill (MIT), those from the National Climatic Data Xinrong Wu(National Marine Data and D. Menemenlis (JPL/Caltech), Co-authors Center (NCDC) and the Operational Information Service) R. M. Ponte (AER) Thomas Collow (INNOVIM, LLC/NOAA Sea Surface Temperature and Sea Ice Climate Prediction Center), Wanqiu Wang Analysis (OSTIA). Finally, we will share A global (0°~360°~74.25°S~84.75°N) The “Estimating the Circulation (NOAA Climate Prediction Center), Arun results from the assimilation of sea ice ocean reanalysis system has been and Climate of the Ocean” (ECCO) Kumar (NOAA Climate Prediction Center) concentration observations from the established by National Marine Data and Consortium has pioneered in the A new Arctic sea ice reanalysis product NASA Team dataset into the model. Information Service (NMDIS), through advancement of ocean state estimation. is being developed at the NOAA Climate which the global ocean reanalysis over The ECCO estimates combine nearly Prediction Center (CPC), which will multiple decades (1958-2015) have been all extant observations of the ocean be used to initialize sea ice forecasts. produced for the global oceans. with a state-of-the-art ocean general circulation model spanning the globe, Experimental Arctic sea ice outlooks Evaluations have been performed on the by adjusting its atmospheric forcing have been produced at CPC since 2015 general reanalysis quality, the climate- and other independent controls, over using sea ice thickness initialization data scale, the meso-scale and synoptic-scale the modern observational era from from the Pan-Arctic Ice Ocean Modeling signals. These evaluations show that the the beginning of continuous satellite and Assimilation System (PIOMAS). reanalysis data produced can provide a altimetry measurements in the early Our plan is to replace PIOMAS with a good representation of ocean processes 1990s to the present. The estimates are and phenomena in the global ocean, characterized by their dynamical and

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 48 Section 1 kinematical consistency, allowing for the scope and usability of the ECCO surface dedicated reanalysis dataset of land reanalysis allows to incorporate instance for budget closures in terms of Central Estimate will be expanded in from 1979 (beginning of the satellite era) forefront model developments before the explicit physical processes, and making support of the broader climate change that is planned to be continued in Near- production phase. amenable investigations of attribution science community, for instance, by the Real-Time through the C3S operational For example, ERA5-Land could benefit and causation of the oceanic state. development of an open source adjoint service. from a larger discretization of the soil of the ocean model, valuable for diverse This presentation describes the status It is also expected that in a second phase layer permitting better propagation of applications. These products and future and plan of ECCO’s flagship product, of production this dataset will be back the energy and water fluxes through plans for the ECCO Central Estimate will the Central Estimate. “ECCO Version 4” extended to the year 1950. ERA5-Land the vertical dimension of the soil layer be discussed. represents the Consortium’s ongoing will be the result of a single simulation (currently under development). This Central Estimate. First established in driven by near-surface atmospheric paper presents the methodology that 2015, Version 4 is of moderate spatial ERA5-Land: a new state-of-the- fields from ERA5 atmospheric reanalysis will be used to produce the ERA5-Land resolution (40-100km) but with a domain art global land surface and climatic fields at native resolution. dataset, as well as its main strengths and that is truly global, including the Arctic reanalysis dataset Additionally, near surface temperature weaknesses. Ocean. Recent enhancements include and humidity fields will be adjusted using First results obtained from demonstrative use of new observations (e.g., GRACE Author Joaquin Munoz Sabater daily computed environmental lapse- scout-runs will be shown and discussed, ocean bottom pressure and Aquarius sea rates. Affiliation ECMWF and their performance will be assessed surface salinity), model improvements Co-authors One of the added values of ERA5-Land by comparison to in-situ data and other (e.g., geothermal heating, sea ice model), J. Muñoz-Sabater (ECMWF, Reading, with respect to the ERA5 atmospheric long-term available datasets. and additional controls in the estimation UK), E. Dutra (Instituto Dom Luiz, reanalysis is a global projected horizontal (e.g., mixing coefficients, correlated Faculdade de Ciências, Universidade de resolution of approximately 9 km (around uncertainties), that result in a more Lisboa), G. Balsamo (ECMWF, Reading, 4 times finer resolution than ERA5), Historical ocean reanalyses complete and accurate estimate than UK), S. Hirahara (Global Environment and matching the current operational ECMWF (1900-2010) using different data before. Marine Department, Japan TCo1279 operational grid, and therefore assimilation strategies and Efforts are underway to further advance Meteorological Agency), H. Herbasch providing consistent input for Numerical atmospheric forcing the Central Estimate to study Earth’s (ECMWF, Reading, UK), S. Boussetta Weather Prediction and climate studies climate with a focus on improving (ECMWF, Reading, UK), C. Albergel involving land water resources, but Author Chunxue Yang understanding and prediction of global (CNRM, Météo-France), D. Dee (ECMWF, also for downstream applications such Affiliation ISAC-CNR and regional sea level variability and Reading, UK) as those based on hydrological and Co-authors change. The new initiative, called agricultural modeling. Chunxue Yang (Institute of Atmospheric “ECCO-Sea Level”, will incorporate The European Centre for Medium ERA5-Land will also include, for the first Science and Climate Chang, Italian capabilities for coupled ocean and Range Weather Forecasts (ECMWF) is time, an estimation of key land-variables National Research Council, Bologna, ice sheet estimation to improve the implementing, on behalf of the European uncertainty based on meteorological Italy) Simona Masina (The Euro- estimate’s representation of ocean-ice Commission, the Copernicus Climate forcing and model parameters Mediterranean Center on Climate interaction pertinent to sea level rise. Change Service (C3S, http://climate. Change, Bologna, Italy ) and Andrea copernicus.eu/). Among its portfolio of uncertainties supplied by a 10-member The estimation’s spatial resolution will ensemble parallel run, hence providing Storto (The Euro-Mediterranean Center product, C3S is developing the ERA5- on Climate Change, Bologna, Italy) also be refined to eddy-permitting scales Land dataset, a new, state-of-the-art, vital information to land-surface data to better resolve the energetic variations high-resolution, global, hourly land- assimilation systems. The offline nature of the circulation. Simultaneously,

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 49 Section 1

A set of historical ocean reanalyses heat content dataset) during the second covering the period from 1900 to 2010 half of the century. In order to reproduce Land Surface Reanalysis in the Land-atmosphere weakly coupled are performed and analysed. All the realistic mass transport, mixed layer CMA 40-year Reanalysis assimilation in CERA-SAT reanalyses assimilate vertical profile depth and eddy kinetic energy, it is observations with a 3D-Var assimilation necessary to assimilate vertical profile Author Xiao Liang Author Patricia de Rosnay scheme but differ in the way they use data, although this leads to some Affiliation CMA Affiliation ECMWF SST data, which are either assimilated discontinuities in the reanalysis time Co-authors Co-authors ICOADS observations or nudged to series. Xiao Liang (Affilation 1), Lipeng Jiang P. de Rosnay (ECMWF), D. Schepers monthly HadISST reconstructed fields. The comparison between the two SST (Affilation 2), Chunxiang Shi (Affilation 3), (ECMWF), P. Dahlgren (ECMWF) Both reanalysis systems are forced assimilation strategies shows that both Zhiquan Liu (Affilation 4) by the NOAA/CIRES 20th Century The CERA-SAT coupled climate direct assimilation and nudging scheme Reanalysis version 2 (20CRv2) and The land surface interacts with weather reanalysis for the satellite era (see have their advantages and disadvantages the ECMWF ERA-20C, thus forming and climate through regulation of the presentation by Schepers et al.) is a key and a combination of these two schemes an ensemble of four realizations, plus water and energy fluxes at the land- product of the ERA-CLIM2 European is desirable in future work. control experiments. atmosphere interface. For example, soil project. It relies on an Earth System Finally, the uncertainty of the reanalyses moisture is important for the partitioning approach focusing on atmosphere, Due to large biases at high latitudes, heat content due to the different of the surface energy between latent, ocean, waves, land, and sea ice. In corrections are applied to the 20CRv2 atmospheric forcing is assessed by sensible and soil heat fluxes, and CERA-SAT different data assimilation atmospheric forcing, based on the comparing the root mean square hence affects the soil temperature methods are used for the each comparison with ERA-Interim during difference (RMSD) between pair of and subsequently the near-surface air component of the Earth System. the overlapped period. The reanalyses temperature. The development of land experiments that share the same A hybrid four-dimensional variational are designed to investigate the impact surface reanalysis methods and long- assimilation configuration but are forced data assimilation (4D-Var) is used for the of different strategies for constraining time-series land data products is critical by different atmospheric reanalyses. atmosphere, a 3D-Var with the first guess the SST in long-term assimilation for improving weather and climate at appropriate time (FGAT) is used for experiments, the feasibility of assimilating It turns out that the upper ocean (top forecasts. subsurface observations in the same 700m) heat content RMSD when in-situ the ocean analysis, and a combination of kind of experiments, and the impact of profiles are assimilated is significantly The presentation will discuss current Optimal Interpolation (OI) and simplified the atmospheric forcing. In general, these smaller than the control experiments developments and future plans of the Extended Kalman Filter (EKF) are used ocean reanalyses are able to capture RMSD even during the first half of the CRA-40/land reanalysis, which is a for the land surface. supplemental land surface reanalysis trends and variability of some key ocean XX century, meaning that even a poor CERA-SAT relies on a pioneering coupled system and data product of the CMA 40- parameters. observing network is able to reduce ocean–atmosphere data assimilation year Reanalysis (CRA-40), generated at the atmospheric forcing uncertainty. approach (as does CERA-20C, the A warm bias of SST with 20CRv2 in the the China Meteorological Administration. Conversely, the total column heat content coupled climate reanalyses of the 20th first half of the century leads to incorrect CRA-40 is initiated in 2014, which aims remains unconstrained with respect to century, see presentation by Laloyaux long-term trends, even though SST to construct the China’s first global the atmospheric forcing uncertainty until et al.), with the ocean 3D-Var coupled anomalies are realistically captured. atmospheric reanalysis system and the mid 1950s. to the atmospheric 4D-Var at its outer Heat contents at 0-300m, 0-700m and produce a long-time-series product since loop level. CERA-SAT also extends the 0-2000m have an increasing trend in all 1979. experiments, consistent with available Earth system concept of CERA-20C, by observation-based products (NODC accounting for the full observing system and by including land data assimilation.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 50 Section 1

In CERA-SAT the land-atmosphere data The products especially the estimates analysis of surface parameters including assimilation is weakly coupled, using a of soil moisture, ground temperature screen level temperature, 10m wind Multi-year consistent reanalysis coupled land-atmosphere background and soil temperature are assessed speeds, mean sea-level pressure (MSLP), of physical and biogeochemical forecast and separate analyses for the by comparing with a large number of soil temperatures, soil moisture and 24 variables in the North Sea and atmosphere and for the surface (screen ground-based observations. Compared h rainfall accumulations. The quality Baltic Sea level variables, soil moisture and snow). with other land surface reanalysis of the 3-D variational data assimilation Conventional and satellite observations products, the hallmark of CRA-40/ used in the reanalysis is also assessed. Author Ye Liu that inform on the state of both land is the use of much more observed Preliminary analysis shows that it takes Affiliation SMHI subsystems are assimilated. precipitation in China to drive the land almost 12 months to spin up the deep Co-authors surface model. CRA-40/land has not soil in terms of moisture, justifying the They are located at the land-atmosphere Ye Liu (Swedish Meteorological and yet benefit from the assimilation of land choice of running year-long spin up interface and include two-meter Hydrological Institute); Lars Axell surface observations. The advantages, periods. temperature and relative humidity, snow (Swedish Meteorological and challenges and future plans of depth, and soil moisture. In this poster Overall, the model performed Hydrological Institute) assimilation observations into the system we present the land-atmosphere weakly consistently over the time period. will be discussed in the presentation. coupled assimilation approach used in Small biases were found in screen- A multi-year physical and biogeochemical CERA-SAT. level temperatures, MSLP and 10m reanalysis was carried out in the Baltic wind speed. Soil temperatures are Sea and North Sea. The model system is Perspectives of coupling enhancement Met Éireann high resolution well represented by the model. 24 h based on the Swedish coastal and ocean using EDA-based (Ensemble Data reanalysis for Ireland accumulations of precipitation generally biogeochemical model (SCOBI) coupled Assimilation based) cross correlation Author Emily Gleeson exhibit a small positive bias of 1mm per to the NEMO-Nordic circulation model estimates and land-atmosphere coupling Met Éireann day and negative biases over mountains (Hordoir et al., 2015). A weak coupled at the outer loop level with 4D-Var are Affiliation due to a mismatch between the model data assimilation system based on a discussed as perspective for future Co-authors orography and the geography of the sequential ensemble interpolation kalman generation of coupled reanalyses. E. Gleeson (Research, Environment and region. MÉRA outperforms the ERA- filter (SEIK) was adopted to merge the Applications Division, Met Éireann, information of model and observations. CRA-40/land is an off-line subsystem of Dublin, Ireland), E. Whelan (Research, Interim reanalysis, particularly in terms CRA-40, which is designed to provide Environment and Applications Division, of standard deviations in screen-level The high resolution remote sensing land surface components such as Met Éireann, Dublin, Ireland), J. Hanley temperatures and surface winds. This sea surface temperature, salinity and ground temperature, soil moisture, snow, (Research, Environment and Applications dataset is the first of its kind for Ireland temperature profiles, oxygen and etc. CRA-40/land system is constructed Division, Met Éireann, Dublin, Ireland) and is now publically available. nutrient profiles observations were based on the LIS (Land Information assimilated into the NEMO-SCOBI. The System) which is developed primarily The Irish Meteorological Service, Met observation errors were decreased with by NASA and has been used in CFSR- Éireann, has carried out a 35-year very increasing the water depth. In order to land reanalysis. A 10-year CRA-40/land high resolution (2.5 km horizontal grid) produce dynamic consistent analysis, experimental product is produced with regional climate reanalysis for Ireland both physical and biogeochemical the horizontal resolution of about 30km using the ALADIN-HIRLAM numerical observations were assimilated in the and the time frequency of 6 hours. weather prediction system. Here we same time. provide an overview of the reanalysis, called MÉRA, as well as a preliminary

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 51 Section 1

Based on the numerical experiment with The model component is the NEMO 75 vertical levels) with the NEMO model and without data assimilation, the inter- Performance and quality platform driven at the surface by ECMWF and driven at the surface by ERA-Interim comparison was implemented to validate assessment of the Copernicus ERA-Interim reanalysis. Observations are reanalysis. the reanalysis results. The model has assimilated by means of a reduced-order Marine Service global ocean The reanalysis system uses a multi- reproduced the variability of ocean and Kalman filter with a 3D multivariate modal eddy-resolving physical data and multivariate reduced order biogeochemical parameters in important decomposition of the background error. Kalman filter based on the singular dynamic processes (e.g. the inflow reanalysis GLORYS12V1 extended evolutive Kalman (SEEK) filter process). However, it was found that the Author Jean-Michel Lellouche formulation together with a 3D-VAR large model simulation yielded obvious biases, Performance and quality Affiliation Mercator Ocean scale bias correction. The assimilated especially in the deep layers. assessment of the global ocean Co-authors eddy-permitting physical observations are along-track satellite As expected, the assimilation has altimetry, sea surface temperature, sea J.-M. Lellouche (Mercator Ocean), reanalysis GLORYS2V4. been found to impart significant O. Le Galloudec (Mercator Ocean), ice concentration and in-situ profiles of positive impact in both the physical E. Greiner (CLS), G. Garric (Mercator Author Gilles Garric temperature and salinity from CORA data and biogeochemical simulations. For base. Ocean), C. Regnier (Mercator Ocean), M. Affiliation Mercator Ocean example, with the comparison with Drevillon (Mercator Ocean), R. Bourdalle- With respect to the previous version, observations, the oxygen, nutrients, Co-authors Badie (Mercator Ocean), C. Bricaud GLORYS2V4 contains the following temperature and salinity biases in G. Garric (Mercator Ocean), L. Parent (Mercator Ocean), Y. Drillet (Mercator main improvements: a) a new initial reanalysis at the Baltic proper has been (Mercator Ocean), E. Greiner (CLS), M. Ocean), P.-Y. Le Traon (Mercator Ocean) temperature and salinity conditions significantly reduced relative to reference Drévillon (Mercator Ocean), M. Hamon derived from EN4.1.1 data base and run. Furthermore, the reanalyzed hypoxia Over the past years, Mercator Ocean (Mercator Ocean), JM Lellouche better balanced with altimetry, b) the use in the Baltic Sea is closer to the observed has been regularly upgrading its global (Mercator Ocean), C. Régnier (Mercator of the updated delayed mode CORA4.1 one relative to the reference run. ocean physical reanalysis through Ocean), C. Desportes (Mercator Ocean), improvements in the ocean model, O. Le Galloudec (Mercator Ocean), C. in situ observations from CMEMS, The results denoted that as a assimilation scheme and assimilated Bricaud (Mercator Ocean), Y. Drillet c) a better observation operator in consistent reanalysis of physical and data sets. The last upgrade concerned (Mercator Ocean), F. Hernandez (Mercator the assimilation scheme for altimetry biogeochemical in the Baltic Sea and the eddy-permitting reanalysis Ocean), C. Dubois (Mercator Ocean) and observations d) a new hybrid Mean North Sea, the output data set of this GLORYS2V4 (1/4° horizontal resolution P-Y. Le Traon (Mercator Ocean) Dynamical Topography (MDT) referenced reanalysis can inform the management of and 75 vertical levels) covering the over the 1993-2013 period, e) an updated The last upgrade of global ocean the North Sea and Baltic Sea ecosystem. altimetry era (1993-2016). R&D activities correction of large scale atmospheric reanalysis GLORYS2V4 produced at For exampling the analysis or prediction have been conducted at Mercator Ocean surface precipitations fluxes and f) an Mercator Ocean that covers the altimetry of the trend and reason of oxygen in 2016/2017 in order to propose, in update of the global climatological runoff era (1993-2016) has been performed in deficiency potentially threatening. the framework of Copernicus Marine data base together with a better account the framework of Copernicus Marine Environment Monitoring Service of freshwater fluxes from polar ice sheet’s Environment Monitoring Service (CMEMS), an eddy-resolving physical glaciers. (CMEMS; http://marine.copernicus.eu/). reanalysis called GLORYS12V1, covering The reanalysis is run at eddy-permitting The new reanalysis outperforms the the same time period and based on resolution (1/4° horizontal resolution and previous version in many aspects and the current real-time global forecasting the presentation will give an overview CMEMS system (1/12° horizontal of main results. The new altimetry and resolution and 50 vertical levels).

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 52 Section 1 water masses equilibrium in the system reanalysis archive (Bollmeyer et al. 2015), of the operational production, which particularly improves the representation a 6 km-resolution reanalysis project Status of ERA5 Reanalysis started in 2016, will be presented. The of global thermo-haline content with a covering the CORDEX european domain Operational Production at results are continuously monitored using trend of +3.56 mm/year for Global Mean that is currently in production. ECMWF a system of diagnostic and monitoring Sea Level together with a +1.8 mm/year tools. Currently, the ERA5 Reanalysis The assimilation of the upper air and for the thermo-steric signal. Author Raluca Radu dataset is partially available and will surface conventional observations will Affiliation ECMWF provide a large number of essential be performed by using the continuous climate variables within the C3S climate nudging technique. Horizontal resolution Co-authors SPHERA (High Resolution data store (CDS). REAnalysis over Italy): plan will allow the representation of deep R. Radu (ECMWF), P. Berrisford (ECMWF), A. Bonet (ECMWF), H. and setup convection and temporal resolution will be sufficient to resolve the diurnal Hersbach (ECMWF), J. Hodkinson The ECMWF ocean-sea ice Author Ines Cerenzia cycle. The dataset will cover the (ECMWF), A. Horanyi (ECMWF), C. Soci reanalysis system ORAS5 and (ECMWF) and M. Suttie (ECMWF) Affiliation ARPAE-Emilia Romagna period 1979-2016. Specific tests will operational ocean analysis be undertaken in order to compare a Co-authors The ERA5 Reanalysis, the successor of subset of SPHERA archive with the high- Author Hao Zuo Ines Cerenzia (ARPAE-Emilia Romagna), ERA-Interim Reanalysis, is a state-of- resolution observative analysis derived Tiziana Paccagnella (ARPAE-Emilia the-art reanalysis covering the satellite Affiliation ECMWF from the regional networks over Italy (e.g. Romagna) era (1950 – present). It is currently Co-authors ERACLITO Antolini et al. 2015, ARCIS produced at ECMWF in the framework of H. Zuo (ECMWF)M. A. Balmaseda Pavan et al. 2013, EURO M-APGD Isotta In a framework of developing interest 4 the Copernicus Climate Change Service (ECMWF), K. Mogensen (ECMWF),S. et al. 2014). of EU Community towards high resolution (C3S). ERA5 is the first reanalysis to be Tietsche (ECMWF)P. de Rosnay (ECMWF) regional reanalysis, ARPAE-SIMC The project aims at having a high produced operationally as a service, proposes the development of SPHERA resolution, space and time consistent, rather than as a research project. With A new operational Ocean ReAnalysis (High Resolution REAnalysis over monitoring of past decades climate respect to its predecessors, ERA5 System 5 (ORAS5) has been Italy), the first dynamical downscaling over Italy and its surrounding Seas at benefits from various improvements implemented at ECMWF. It spans reanalysis of the atmosphere centred the same time for climatic assessments in the data assimilation, model and the period 1979 to present and was over Italy with a horizontal resolution (trend along the past years, climate observing systems from recent years. For produced using NEMO Ocean Model of 2.2km and a high frequency. reference for COSMO applications in the historical period production is divided coupled to LIM2 sea ice model. Subsurface in-situ observations from The Italian reference NWP model for different scenarios associated to Climate into parallel streams, each spanning a EN4, SLA from AVISO DUACS2014, operational limited area forecast, i.e. the Change over Italy) and for feeding period of 10 years, while for the present SST from HadSST2/OSTIA and Sea COSMO (Consortium for small scale downstream high-resolution model time ERA5 is produced daily near to real Ice Concentration from OSTIA were modelling) model will be applied to applications. The project is expected to time (NRT). assimilated in ORAS5 using NEMOVAR perform the dynamical downscaling. be accomplished within the end of 2019. Each stream comprises a lower Ocean data assimilation system (in 3DVar This effort will complement the activity of resolution 10 member 4D-Var ensemble FGAT approach). the DWD, Deutscher Wetterdienst, and of (EDA) providing flow-dependent Here we describe the most important the University of Bonn on the same field, background error information to the system upgrades in ORAS5, including since the initial and boundary conditions high resolution (HRES) deterministic increase of model resolution; change will be based on the COSMO-REA6 assimilation cycle. The overview of the production system and the current status to a coupled ocean-sea ice model

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 53 Section 1 and sea ice data assimilation; updated Re-analysis ensemble product (GREP). Assimilation of the sea ice will create all scales, which have the ability to model forcing and observation datasets; The current version of this re-analysis better consistency, along with a better and describe the distribution of possible and implementation of a generic centres around the NERC/Met Office sea ice thickness climatology. events and as such the variability of perturbation scheme that accounts Joint Ocean Modelling Programme extreme weather, its variables and for representativeness errors from (JOMP) Global Ocean 5.0 (GO5.0) and the phenomena. observation and structure and analysis NERC/Met Office Joint Sea Ice Modelling Towards a high-resolution We describe the setup of the ensemble errors from surface forcing fluxes. Programme (JSIMP) Global Sea Ice probabilistic regional reanalysis data assimilation (EDA) and forecasting version 6 (GSI6). system based on a local The operational implementation of systems which have been developed at real-time extension of ORAS5 is also A planned update to an improved version ensemble transform Kalman DWD, including the ICON global model discussed; this provides ocean and sea- GO6/GSI8 version is expected within the filter with its hybrid ensemble variational data ice initial conditions for the ECMWF’s next calendar year. The new version, Author Thomas Roesch assimilation (EnVAR) and the ensemble coupled ensemble forecasting system based on NEMO vn3.6 and CICE 5.1 will prediction system ICON-EPS as well Deutscher Wetterdienst (spanning the medium range, monthly include a variable volume level scheme Affiliation as the high-resolution ensemble data and seasonal forecasts ranges). Results for the ocean, a parameterisation for Co-authors assimilation system COSMO-KENDA from evaluation of ORAS5 with observed under-ice-shelf melt, pronostic icebergs, Thomas Roesch (DWD), Lilo Bach (DWD), (Kilometer Scale Ensemble Data data, e.g. using RAPID-derived transport and a multi-layer sea ice thermodynamic Roland Potthast (DWD), Frank Kaspar Assimilation). and re-processed sea-level data are scheme along with an improved (DWD), Jan Keller (DWD, Uni Bonn) The latter is the operational system of also discussed, with the focus on some representation of melt-ponds. We will The question of high-impact weather and DWD and used by further members of prominent climate signals. show some initial results from this latest its relation to climate change today is of the COSMO consortium. It drives the configuration, contrasting and comparing tremendous importance for all parts of high-resolution ensemble forecasting the advancements over previous versions our modern world. It touches all basic system COSMO-DE-EPS. We The GloSea/FOAM ocean and in terms of several ocean and sea ice layers of a modern society, from logistics demonstrate the high quality of the sea ice re-analysis: Current monitoring indicators such as heat and and production to national safety,from system. status and future plans salt content, surface currents, sea ice renewable energy political strategy and volume, along with root mean square We will then give perspectives on the use Author K Andrew Peterson daily energy supply to personal holiday errors with the ingested observations. of the coupled ICON-EPS COSMO-EPS planning. National weather services Affiliation Met Office Additionally, recent advancements ensemble system for the investigation and research institutions are reacting Co-authors towards the assimilation of sea ice of climate variability for reanalysis to the increasing need to estimate risk K.A. Peterson (Met Office), C MacLachlan thickness to satellite observations will and climate projection, which is under and distributions of both standard (Met Office), C. Harris (Met Office), be presented. Our current systems only investigation by DWD core teams in variables of weather and climate such A. Aguiar (Met Office), M.J. Martin assimilate sea ice concentration, allowing collaboration with the Hans-Ertel center as temperatures or humidity and high- (Met Office), E. Blockley (Met Office) model physics to integrate the thickness HErZ in Bonn. impact phenomena such as strong properties of the sea ice. This has been precipitation, wind gusts and storms, As part of the seasonal forecast system shown to depend on the external forcing tornados, hurricanes or fog. at the Met Office, a 1/4 degree ocean and applied to the model, and has lead to sea ice analysis is performed for 1990 inconsistencies between the Met Office The agenda of weather and climate to near real time. This analysis is one of real time sea ice analysis and re-analysis. forecasting and projection today includes 4 members of the Copernicus Marine the development and operation of Environment Monitoring Service Global ensemble forecasting systems (EPS) on

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 54 Section 1

km respectively or even the current ERA5 UERRA SMHI HARMONIE- at about 30 km. This gives much more ALADIN high resolution Regional detail in precipitation, temperature and Reanalysis over Europe for wind near the surface. 1961-2015 The system is very efficient and parallel 10 year streams were run with 4 months Author Per Undén spin up periods. The output data, Affiliation SMHI including observation statistics, are Co-authors stored on ECFS at ECMWF but the fields Per Undén (SMHI),Martin Ridal (SMHI), have been archived in the common Esbjörn Olsson (SMHI), Jelena Bojarova UERRA MARS archive. The reanalysis (SMHI), Klaus Zimmermann (SMHI), will be presented and compared to Heiner Körnich (SMHI) and Eric Bazile the ERA reanalyses together with the (Météo-France) different data types stored, as well as observation usage and diagnostics using SMHI is coordinating the FP7 Project a partly newly developed observation UERRA (Uncertainties in Ensembles monitoring system. of Regional ReAnalyses) which has developed three full upper air Regional European Reanalysis systems and two 2-dimensional ones. The project is now in its final phase and all data is archived in an openly available UERRA archive with common parameters within MARS at ECMWF. At SMHI historical data assimilation and forecast cycles have been produced for the period 1961 until 2015 using the HARMONIE-ALADIN system. It has been run at 11 km horizontal resolution with conventional observations and a large scale constraint that adapts large scales to the global driving ERA reanalyses. ERA40 and ERA-Interim reanalyses exist during this period and provide boundary forcing. The horizontal grid resolution in UERRA of about 11 km is much higher than the global ERA analyses at 125 or 78

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 55 of velocity and the CNES-CLS13 Mean on Climate Monitoring (CM SAF, funded in June the Arctic albedo of the Canadian Section 2 – Dynamic Topography. Ekman currents by the European Organisation for the coast has slightly increased since Observations for at two levels (surface and 15m) are Exploitation of Meteorological Satellites 2008/2009. calculated from an empirical model. The (EUMETSAT)) data record CLARA-A2 The maximum increase of the June reanalyses model parameters (amplitude and angle) SAL (CM SAF cLoud, Albedo and surface albedo during 1982/1983 – 2014/2015 have been derived as to minimize the RAdiation dataset from AVHRR data – is 0.55 and the maximum decrease is misfit between wind stress data and the Edition 2, surface albedo), which covers A 24 year observation-based -0.51. During 2008/2009 – 2014/2015 ageostrophic component extracted from the years from 1982 to 2015, in the reanalysis of ocean surface the corresponding increase for albedo in in-situ drifter velocities (SVP drifters at resolution of 0.25° (global product). The currents from the GlobCurrent August is 0.30 and the decrease -0.40. 15m depth, Argo floats at the surface). SAL albedo contains contributions both project from the sea ice and the open ocean. A regional product for the Mediterranean The previous CLARA-A1-SAL release Author MARIE-HELENE RIO Sea has also been produced over the Assessing the impact of GPS already showed a dramatic decrease Affiliation CLS same time period. Obtained currents radio occultation measurements in the surface albedo of the Arctic sea have been validated through comparison in ERA5 Co-authors ice area during 1982-2009. Variations in to independent in-situ observations and M-H Rio (CLS), C. Dufau (CLS), H. Etienne mean sea-ice albedo could be explained Author Sean Healy other existing products based either on (CLS), S. Mulet (CLS), G. Larnicol (CLS), using sea-ice concentration, surface air observations or model outputs. Affiliation ECMWF J. Johannessen -NERSC), C. Donlon (ESA) temperature and elapsed time from onset Co-authors of melt as drivers. Accurate estimate of ocean surface S B Healy (ECMWF), A Horanyi (ECMWF), currents is both a challenging issue Arctic sea ice albedo time series The CLARA-A2 SAL data set shows a A J Simmons (ECMWF) and a growing end-users requirement. 1982-2015 according to the continuation of the albedo decrease in the Advancing the quantitative estimation CLARA-A2-SAL product by CM Siberian and Scandinavian coasts during GPS radio occultation (GPS-RO) of ocean surface currents from satellite SAF 2009-2015, whereas the Canadian coast measurements are now a key sensor synergy and demonstrating the shows an albedo increase from 2009 to observation type forclimate reanalyses. impact in user-led scientific, operational Author Terhikki Manninen 2015. The maximum increase of the August They can be assimilated without and commercial applications was the Affiliation Finnish Meteorological albedo during 1982/1983 – 2014/2015 bias correction, and they perform main objective of the GlobCurrent Institute is 0.32 and the maximum decrease is the role of “nchor measurements” in variational radiance bias correction project, a Data User Element (DUE) from Co-authors -0.40. During 2008/2009 – 2014/2015 the European Space Agency (ESA) which K. Anttila (Finnish Meteorological the corresponding increase for albedo in schemes. The measurements provide run from October 2013 to June 2017. Institute), T. Manninen (Finnish August is 0.31 and the decrease -0.27. accurate temperature informationin the Meteorological Institute), E. Jääskeläinen upper troposphere and lower/middle In the framework of this study, a global The variation of the Arctic surface stratosphere. reanalysis of 24 years (1993-2016) of (Finnish Meteorological Institute), A. albedo in June in 1982/1983 – 2014/2015 global ocean currents at two depths Riihelä (Finnish Meteorological Institute) shows a decrease in a larger area, thus Furthermore, they have improved the (surface and 15m) has been calculated consistency between stratospheric A new 34 –year long time series of surface indicating that the sea ice concentration as the sum of the geostrophic and temperature reanalyses since 2007, albedo was used to study the changes in has decreased also in June. In Hudson Ekman components. The geostrophic when GPS-RO numbers increased with the albedo of the Arctic sea ice. The study Bay the location of sea ice changed from component is based on the SSALTO- the introduction of COSMIC data. In is based on the surface albedo monthly the western side to the eastern side. Also DUACS multi-mission altimeter maps this talk we review the measurement means of the Satellite Application Facility

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 56 Section 2 technique, and describe how GPS-RO levels, from research institutes to the the interpolation process not only outliers in-situ profiles for instance or which measurements are assimilated in ERA5. various data centers. The Climatological but also biases distorting a natural offer only a surface view of the ocean as We will demonstrate that the GPS-RO Atlas of Nordic Seas and Northern variability. The observed data used in satellite data. measurementsreduce stratospheric North Atlantic presents a new step the Atlas passed through an extensive The originality of the ARMOR3D biases in ERA5, and that GPS-RO towards compiling a complete dataset of quality check, with the biases-suspicious observation based product is to take and AMSU-A channel 14 provide observed data and derived climatological instruments were eliminated from the advantage of the strengths of these 2 complementary information. fields. analysis altogether. types of data by combining satellite More specifically, it will be demonstrated The dataset, especially the historical For spatial interpolation of oceanographic SLA and SST datasets with in-situ T, S that AMSU-A channel 14 can constrain measurements, were considerably data, we use a technique known as vertical profiles in order to build a global biases in the GPS-RO “null-space”. We improved, while the climatological Data-Interpolating Variational Analysis 3D weekly temperature, salinity and will also present new results assessing gridded fields were computed by developed by University of Liège. We geostrophic velocities fields at a spatial the quality and impact of data from means of the state-of-the-art spatial believe that the Atlas will be a useful tool 1/4° resolution. GPS/MET mission from 1995-1997. interpolation technique. This Atlas is for a large variety of applications and will The mesoscale content of the satellite Although the GPS/MET data availability built upon a dataset developed at the provide a basis for future improvements. data and the vertical sampling of the is sporadic, we will show that it is still Arctic and Antarctic Research Institute in-situ profiles are complementary in this a useful dataset for testing reanalysis containing vast amount of Russian statistical approach. Also, this method systems during this period. observations including those collected CMEMS multi-observations need to use a reliable mesoscale SSS during extensive Soviet field programs in products to monitor ocean state field. We use the combined SSS/SSD the northern North Atlantic and Nordic Author Sandrine Mulet field computed at CNR from an optimal Climatological Atlas of the Seas. Nordic Seas and Northern North Affiliation CLS interpolation of in-situ data using SST Atlantic As a part of the Atlas effort, this AARI Co-authors gradients to add mesoscale features. dataset was converted to a modern Sandrine Mulet (CLS), Stéphanie ARMOR3D and the combined SSS/SSD Author Alexander Smirnov database format and updated to include Guinehut (CLS), Nathalie Verbrugge products are part of the Copernicus Affiliation AARI international observations from multiple (CLS), Bruno Buongiorno-Nardelli (CNR), Marine Environment Monitoring Service sources using modern software for (CMEMS) through the Global observation Co-authors Riccardo Droghei (CNR), Marie Drévillon quality control. Our main objective was to component of the Global Monitoring and Alexander Smirnov (Arctic and Antarctic (Mercator-Océan), Jérome Gourrion compile a gridded climatological dataset forecasting center. Research Institute, St. Petersburg, (CNRS/Coriolis), Andrea Storto (CMCC), to support studies of ocean variability Russia), Alexander Korablev (Geophysical Hao Zuo (ECMWF), Drew Peterson (UK A full reprocessing from 1993 to 2016 during the period of instrumental Institute, Bergen, Norway) Met Office) and near-real-time fields since 2014 are observations. There are at least three available through the CMEMS web portal. interfering circumstances: (1) insufficient To have a synoptic view of the 3D Since the beginning of instrumental The range of applications of this product number of observations, (2) inadequate ocean to pursue oceanic studies, a measurements more than a century goes from mesoscale to large-scale data quality control and (3) limitations multi observations gridded product can ago, oceanographic observations have studies. It could be used both for the associated with interpolation techniques. be often useful instead of using raw been conducted by various marine evaluation of re-analyses and for ocean observations which can be irregularly organizations and stored in different The first obstacle is the most critical. climate studies. For instance, ARMOR3D distributed in space and time as the formats on different media. Numerous Thus, a labor-intensive work was needed contributes to the annual CMEMS Ocean attempts were made to collect and to improve the observed dataset. State Report (OSR). merge observations together at different Inadequate quality control introduces into

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 57 Section 2

In this framework, ARMOR3D have been Predictions regarding the future climate approaches. Here we report on the first can also be found (Sea mammals compared with 6 other global ocean and the state of African tropical forest half year of data recovery of the first profiles from MEOP, XBT datasets reanalysis/reprocessing products of remain uncertain in part due to a lack part of some 589 climatological stations from cruises…). (EN4 also takes data CMEMS: an optimal interpolation of in- of legacy data which provides the spread throughout the Congo Basin from the ASBO dataset to supplement situ T/S profiles (CORA-OI from Coriolis), necessary climatological and ecological (http://cobecore.org/map/). We discuss observations in the Arctic). 4 reanalysis (GLORYS2V4 from Mercator context for current research in the Congo progress made in the automation of First advantage of this new merge Ocean, ORAS5 from ECMWF, FOAM/ Basin. Even today, the central Congo data recovery and issues regarding product is to enhance the space and GloSea from Met Office and C-GLORS Basin is currently represented by only a transcription and provide a short time coverage at global and european from CMCC) and the ensemble mean of few rain gauges, limiting climate forecasts overview of preliminary data products. scales for the period covering 1950 these reanalysis (GREP). across the Congo Basin. This lack of till a year before the current year. This long-term (historical) climatological data In this presentation, the main steps of product is updated once a year and T&S leaves the central Congo Basin spatially Comparison of CORA and EN4 the ARMOR3D and the combined SSS/ gridded fields are alos generated for the and temporally under-represented. in-situ datasets validation SSD production systems are described. period 1990-year n-1. The enhancement However, old climate records could methods, toward a better quality Then, results from ocean reanalysis/ compared to the revious CORA product provide valuable information in support of reprocessing intercomparison are merged dataset. will be presented. Despite the fact that climate re-analysis. presented: hydrographic variability are Author Szekely Tanguy the profiles distributed by both datasets analyzed in all products in terms of spatial The historical archives of La régie des are mostly the same, the quality control Affiliation CNRS patterns and time evolution. Robust plantations de la colonie (REPCO) procedures developed by the Met Office features and weaknesses are highlighted and the Institut National d’Etudes Co-authors and Copernicus teams differ, sometimes and uncertainty levels are provided. Agronomique du Congo Belge (INEAC), T. Szekely, R.Killick, J.Gourrion, A.Piron, leading to different quality control flags cover six decades (1901–1960). Located G. Reverdin for the same profile. at the State Archives of Belgium, the CORA and EN4 are both global delayed Started in 2016 a new study started COBECORE: recovering (eco-) Royal Museum for Central Africa and the time mode validated in-situ ocean that aims to compare both validation climatological data from Belgian Botanic Garden Meise, they hold vast temperature and salinity datasets procedures to move towards a colonial archives. amounts of (eco-) climatological data, distributed by the Met Office (http://www. Copernicus Marine Service dataset with great potential and relevance for Author Koen Hufkens metoffice.gov.uk/) and Copernicus (www. with the best features of CORA and basic and applied research in the central marine.copernicus.eu). A large part of the EN4 validation. A reference data set Affiliation Harvard University Congo Basin. profiles distributed by CORA and EN4 composed of the full set of in-situ Co-authors Their scientific value resides in the in recent years are Argo profiles from temperature and salinity measurements Koen Hufkens1, Kim Jacobsen2, Hans extent of the data collected in a the ARGO DAC, but profiles are also collected by Coriolis during 2015 is used. Beeckman2, Piet Stoffelen3, Filip region where the availability of reliable extracted from the World Ocean Database These measurements have been made Vandelook3, Jan Van den Bulcke4, baseline measurements are practically and TESAC profiles from GTSPP. thanks to wide range of instruments Michael Amara5, Hans Verbeeck61 absent. The COBECORE project (http:// (XBTs, CTDs, Argo floats, Instrumented Richardson Lab, Harvard University, In the case of CORA, data coming from cobecore.org) aims to establish baseline sea mammals,…), covering the global 2Xylarium, Royal Museum for Central the EUROGOOS Regional operationnal climatological measurements, crucial for ocean. Africa, 3Botanic Garden Meise, oserving system (ROOS) operated by reanalysis, by valorizing climatological 4Laboratory of Wood Technology, Ghent European institutes no managed by legacy data through computer vision, University, 5State Archives Belgium, National Data Centres and other datasets machine learning and citizen science 6CAVElab, Ghent University of profiles povided by scientific sources

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 58 Section 2

The reference dataset has been validated Meteorological Service) in Hamburg from China, Korea, the tropical Pacific, For example, quality control, simultaneously by both teams. An holds an archive of several collections Cameroon and Togo and Canada has transmission interruptions, and station exhaustive comparison of the validation of original historical world-wide weather been completed. The presentation will outages can occasionally affect data test results is now performed to find the records from land stations and ships. show the recent progress of the digitization availability. While orbital paths can be best features of both datasets. efforts and ongoing analysis of the data. known, drift in certain instruments and The archive originates from the Deutsche the large number of available instruments The study shows the differences Seewarte (German Marine Observatory), An important activity is the further makes it challenging to know which between the EN4 and CORA validation which was the predecessor organisation development of automatic quality control satellite is observing any region at any results. It highlights the complementarity of DWD in Hamburg. The largest archive procedures, where the main task is to point in the diurnal cycle. between the EN4 and CORA higher is the collection of meteorological adapt the modern QC limits to the lower order tests. The design of the CORA and logbooks from sailing ships and accuracy of the historical observations, Furthermore, there is information from EN4 validation charts is discussed to steamers. It contains about 37,000 different weather classifications, units the statistics generated by the data understand how a different approach on individual journals with an estimated total and conventions. assimilation that can help understand the the dataset scope can lead to differences amount of 23 Million observations that model and the quality of the reanalysis. in data validation. The new validation start in 1829 and end in 1945. Typically, the assimilated observations chart of the Copernicus Marine Service Development of Gridded and their innovations are in observation- The majority of the observations are dataset is presented. Innovations and Observations space data formats and have not been from the period from 1853 to 1934. The supplement to MERRA-2 made easily available to reanalysis users. digitization procedure for the journals Data Rescue of Historic includes the registration of metadata, Author Michael Bosilovich A test data set has been developed Observations from the Archives archiving of optical scans and manual Affiliation NASA GSFC GMAO to make the MERRA-2 assimilated transcription of the observations. The observations available for rapid and of the German Marine Co-authors data are quality checked and transferred general use, by simplifying the data M.G. Bosilovich (NASA GSFC GMAO), Observatory into a data base. About 11 Million format. The observations are binned to A.M. daSilva (NASA GSFC GMAO) Author Axel Andersson observations are already stored in the a grid similar as MERRA-2 and saved as data base. However, a large number of net CDF. This data collection includes the Affiliation Deutscher Wetterdienst Atmospheric reanalysis have become these observations have been digitized an important source of data for weather mean and number of observations in the Co-authors during previous decades and still have and climate research, owing to the bin as well as its variance. A. Andersson (DWD), B. Tinz (DWD), to be assigned a respective metadata continuity of the data, but especially The data will also include the innovations L. Gates (DWD) record. Apart from ship observations, because of the multitude of observational from the data assimilation, the forecast the Deutsche Seewarte also operated Historic observational data records are data included (radiosondes, commercial departure and the analysis increment, a world-wide net of overseas an important contribution for climate aircraft, retrieved data products and as well as bias correction (for satellite meteorological land stations, many of reconstructions and analysis of past radiances). However, the presence of radiances). We refer to this proof-of- them situated at the coast or on islands. weather events. Particularly in remote assimilated observations can vary based concept data as the MERRA-2 Gridded and data sparse regions, such as the The archive consists of more than 1500 on numerous factors, and so it is difficult Innovations and Observations (GIO). In open ocean, newly rescued data can stations, mostly from the periods from or impossible for a researcher to say with this paper, we present the data format significantly improve the knowledge 1884 to 1943. Nearly 200 stations have any degree of certainty how many and and its strengths and limitations with about weather and climatic conditions already been digitized with a digitization what type of observations contributed to some initial testing and validation of the in earlier decades and centuries. procedure similar to that of the ship the reanalysis data they are using at any methodology. Deutscher Wetterdienst (DWD, German observations. Digitization of the data give point in time or space.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 59 Section 2

Since about 15 years, the EUMETSAT (ocean and land), regional land fluxes 19th and early 20th century is one of EUMETSAF’s Climate Monitoring Satellite Application Facility on Climate (Meteosat domain), global high clouds. the most significant advances in climate SAF: A sustained provision of Monitoring (CM SAF, www.cmsaf.eu) This presentation will highlight results sciences. develops capabilities for a sustained from the currently available CDRs and Climate Data Records for Our confidence in using these data sets generation and provision of Climate Data will present an overview of the upcoming Evaluation and Climate to reconstruct past climate variability Records (CDRs) derived from operational new editions of CDRs. requires careful efforts to validate Monitoring meteorological satellites, which will be them against observations, especially continued in the current phase until 2022. Author Rainer Hollmann in the Arctic, where the network of The ultimate aim is to make the resulting Evaluation of reanalyses for the Affiliation Deutscher Wetterdienst meteorological stations is sparse. In this data records suitable for the analysis of Arctic based on instrumental paper we have compared different kinds Co-authors climate variability and the detection of historical observations of measured meteorological data with R. Hollmann (Deutscher Wetterdienst), climate trends. M. Schröder (Deutscher Wetterdienst), Author Rajmund Przybylak reanalysis products. Early-instrumental K. Fennig (Deutscher Wetterdienst), The product portfolio of the CM Affiliation Nicolaus Copernicus (1801–1920) atmospheric pressure data M. Stengel (Deutscher Wetterdienst), SAF comprises long time series of University, Department from land stations covering the entire high J. Trentmann (Deutscher Wetterdienst), Essential Climate Variables (ECVs) of Meteorology and Arctic have been compared with data P. Fuchs (Deutscher Wetterdienst) related to the energy & water cycle as Climatology (grids located nearest the historical sites) defined by Global Climate Observing taken from the 2nd version of the 20th Co-authors In recent decades climate variability and System (GCOS). Thus, users have Century Reanalysis Project (20CRv2). R. Przybylak (Nicolaus Copernicus change have caused impacts on natural access to many parameters of the University, Department of Meteorology Another of our evaluations used air and human systems on all continents. water and energy cycle based on and Climatology), P. Wyszy´nski (Nicolaus temperature taken from 20CRv2 and Observations are needed to understand operational satellite instruments, but Copernicus University, Department of ERA20C reanalyses for the warm half- and document these interactions of the also to fundamental climate data Meteorology and Climatology), D. Klaus year in the periods 1871–1910 and 1901– climate system. They are increasingly records based on microwave imager (Alfred Wegener Institute Helmholtz 1910, respectively. Data covered the based on remote sensing from satellites measurements thoroughly inter- Centre for Polar and Marine Research), maritime part of the Svalbard archipelago which offer global scale and continuous calibrated and homogenized to be K. Dethloff (Alfred Wegener Institute (74–82°N, 6–30°E). The majority of coverage. Only long term and consistent suitable for assimilation and integration Helmholtz Centre for Polar and Marine the data were taken from a Norwegian observations of the earth system allow us into re-analyses efforts. The time series Research), A. Rinke (Alfred Wegener collection entitled Arctic Norwegian to quantify impacts of climate variability of the climate data records range from Institute Helmholtz Centre for Polar and Logbook Data: 1867–1912 available at and change on the natural and human 8 to more than 30 years with a global Marine Research), T. Strzyz˙ewski the Computational Information Systems dimension. From this understanding coverage for data based on polar (Nicolaus Copernicus University, Laboratory Research Data Archive one can estimate and eventually predict orbiting satellites, while those based on Department of Meteorology and (CISL RDA). Besides data downloaded future states of the earth system and geostationary satellite data cover the Climatology) from the CISL RDA, we also used air quantify its vulnerability and resilience region of the METEOSAT diskntil 2022 temperature data digitized from logbooks to continuing anthropogenic forcing. new editions of climate data records The development of atmospheric gathered by us as part of various data In addition, these observations can be (CDR) will be published extending the reanalyses that assimilate only surface recovery projects. In this research we used in the evaluation and assessment time-range and the portfolio. In particular, data thereby allowing one to extend the have compared air temperature data of reanalyses data records and climate new products related to the following period of the datasets back to the mid from observations made on ships and models. topics will be developed and provided available in logbooks. during CDOP 3 global precipitation

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 60 Section 2

Analysis was conducted for four regions The Southwest China vortex (SCV) is a Furthermore, the radiosonde data To meet this need we propose the (grid boxes, 4° latitude × 12° longitude) very important influence system for the assimilation, from the intensive method HIRAIN to generate an ensemble NW, NE, SW and SE. Finally, we precipitation weather of China during observation scientific experiment of of probable space-time precipitation evaluated data available at 20CRv2 and summer half year. And the torrential SCV, obviously improves the operation fields given a dataset of rainfall observed its newer version (20CRv2c) for Calm Bay rain of SCV is also a much complex and ability of the numerical weather by synoptic stations and infrared (Buchta Tikhaya) located in the Franz distinctive torrential rain in China. SCV forecast in Southwest China. In a word, brightness temperature from Meteosat Josef Land archipelago for the period and its torrential rain are always a key it is necessary to reinforce the field Second Generation. HIRAIN works in two 1930–1940. This study investigated the scientific problem in weather research experiment and expand data application steps. quality of reanalyzed surface quantities, and forecast. for the forecast of SCV and its torrential First, a Bayesian statistical model such as 2-m air temperature, 2-m rain. But, it is not very clear about SCV and its conditional on the observational data specific humidity and 10-m horizontal severe weather because of the absence simulates the latent spatial Gaussian wind speed. Comparison of vertical of meteorological station and the sparse process that drives the occurrence temperature structure produced by two Generation of high resolution of observing data. The research and the of precipitation exceeding a selected versions of 20CR at Calm Bay was based precipitation conditional on understanding on SCV and its torrential threshold. on data taken from PANGAEA – Data rainfall observations and infrared rain are seriously restricted. Based Publisher for Earth & Environmental We adopted a Bayesian approach, since on the situation of scientific research brightness temperature Science. This digital data library provides the data at the observation locations and operational forecast for SCV, this a historical archive of radiosondes and Author Ieda Pscheidt are honored and the spatial covariance paper discusses the field experiment of tracked balloons on standard pressure Affiliation University of Bonn, structure of the spatial process is SCV and its importance for short-term levels back to the 1920s. Meteorological Institute reproduced in each realisation. This weather forecast. And the intensive generates more realistic fields than observation scientific experiment of SCV Co-authors some interpolation method. In a second has been carried out in summer from Petra Friederichs (University of Bonn, Field experiment of Southwest step, realisations of occurrence/non- 2010 to 2017. Meteorological Institute), Dan Cooley China vortex and its applications (Colorado State University, Department occurrence of precipitation exceeding in short-term weather forecast The intensive observation data for SCV of Statistics), Jennifer Hoeting (Colorado the same thresholds are obtained given activities and its weather processes the simulated latent process. HIRAIN Author Yueqing Li State University, Department of has been obtained, and using the Statistics) is extended to several thresholds of Affiliation Institute of Plateau multi-source data from the surface, precipitation amount. A final precipitation Meteorology, China radiosonde, radar observation in daily This study is part of a high resolution product with hourly temporal and 4 km Meteorological weather forecast operation, it has been reanalysis project proposed for Germany spatial resolution is generated from the Administration, Chengdu effectively improved the forecast for SCV and Europe (Bollmeyer et. al., 2014). fields occurrence/non-occurrence of the Co-authors and its torrential rain. The basic feature The reanalysis for Germany assimilates individual thresholds. Yueqing Li (Institute of Plateau and anomalous evolution of SCV have precipitation among other variables. For Meteorology, CMA, Heavy Rain and been deeply and refinedly analyzed in periods after 2007 radar data is used for Drought-Flood Disasters in Plateau and weather map, which further reveal the this purpose. However, for earlier periods Basin Key laboratory of Sichuan Province) structural feature, development process when radar data is not available another and weather influence of SCV. high resolution precipitation dataset is required.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 61 Section 2

our results with ERA-Interim and a similar approach, the SoutheastAsian The latest update of the International Global bias-adjusted radiosonde demonstrate existing humidity biases in Climate Assessment & Dataset (SACA&D) Comprehensive Ocean-Atmosphere humidity ERA-Interim. has been developed in a collaboration Data Set (ICOADS), Release 3.0 (R3.0), with NMSs from the region. provides major coverage expansions on On a preliminary basis we compare Author Michael Blaschek the previous version (R2.5) for 1662-2014, radiosonde humidity measurements Based on the meteorological station Affiliation University of Vienna followed by improved monthly near- also with brightness temperatures from data, a gridded dataset providing daily real-time (NRT) extensions, e.g. partly Co-authors microwave sounders (SSM/T-2, SSMIS). maps of temperature and precipitation addressing the impacts of many masked M. Blaschek (University of Vienna), Results indicate still large discrepancies has been developed. This data set, SA- Global Telecommunication System L. Haimberger (University of Vienna) between brightness temperatures OBS, is introduced in this presentation. (GTS) ship callsigns since late 2007. This calculated from radiosondes and ERA- The spatial resolution of these maps are Radiosonde humidity measurements presentation will describe the data and Interim employing RTTOVv11 compared 0.25 x 0.25 degree, and data spans the are valuable because of their long-term metadata characteristics of R3.0, and to measured brightness temperatures period from 1981onwards. The gridding availability and secondly because of high provide details on new data sources from microwave sounders. techniques used for this data set are vertical resolution of the measurements. and on extensive observational format similar as for the European data set. Nevertheless, no measurement system is updates. without uncertainties and for radiosondes The most recent developments are that Gridded, high-resolution New or improved data sources cover the changes in the observation system for South America, in collaboration with observational data sets for various time periods, from the late 18th lead to more or less clear breakpoints NMSs in the region and the Climatic Southeast Asia and South Century all the way into the modern in the observed long-term time series. Research Unit (University of East Anglia, period. These sources include newly These artificial jumps and biases need to America UK), a similar gridded dataset will be digitized historical observations from be removed and we adapt a well-known developed of which first results will be Author Gerard van der Schrier collections such as the English East bias adjustment scheme from radiosonde presented. Affiliation Royal Netherlands temperature to radiosonde humidity India Company and the German Maury Meteorological Institute measurements. collections, and updated external Co-authors ICOADS Release 3.0: Data archives such as the Global Tropical We use for example ERA-Interim to E.J.M. van den Besselaar (KNMI), R. Characteristics and Future Moored Buoy Array (GTMBA) and World detect such breakpoints and to adjust the Cornes (KNMI, CRU), G. van der Schrier Ocean Database (WOD). time series to a globally more consistent Priorities (KNMI), A. Suwondo (BMKG), Iqbal A major observational format update data set. We apply two methods, one Author Eric Freeman (BMKG), A.M.G. Klein Tank (KNMI) is an extension to include near-surface adjusts the mean between breakpoints Affiliation NOAA/NCEI/ERT, Inc. whereas the other adjusts the quantiles Validation for reanalyses datasets oceanographic data elements such and thus the distribution of humidity. requires access to high-quality andhigh- Co-authors as salinity, nutrients and carbon cycle E. Freeman (NOAA/NCEI/ERT, Inc), A. resolution observational datasets. For parameters. These parameters, with For long-term trend estimates (1979- Anderson (DWD), W. Angel (NOAA/NCEI), Europe, the gridded dailytemperature associated depths, have been populated 2016) of mean humidity both methods P. Brohan (Met Office), L. Gates (DWD), and precipitation fields of the E-OBS from the WOD and other near-surface work well. For low and high percentiles, E.C. Kent (NOC), S. Smith (FSU), S. dataset, based onthe meteorological oceanographic sources. The new however, the distribution matching Worley (NCAR) station data provided by the European inclusion of a unique identifier (UID) to methods works better. We compare NationalMeteorological Services (NMSs) each individual marine report will help to ECA&D (www.ecad.eu), has been to improve traceability and facilitate usedfrequently for these purposes. Using collaboration between ICOADS users.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 62 Section 2

Future plans for ICOADS will be Unique report-level identifiers link described in the second part of ICOADS Release 3.0: New all of these components together to Impact of satellite data on the presentation. The longstanding Relevance and Support for support traceability back to individual reanalysis uncertainty for MARCDAT/CLIMAR user community Reanalyses core records and further strengthen UERRA will continue to actively help shape the the data provenance. Details about the database and improve data management Author Thomas Cram content in these components as well as Author Amy Doherty to meet future needs and continue to Affiliation National Center for their current status will be described to Affiliation Met Office make ICOADS a valuable resource for Atmospheric Research illustrate the new data that are available. Co-authors global climate research well into the (NCAR) Furthermore, the community is invited to A. M. Doherty (Met Office), R. Renshaw future. The SOT is also a highly valuable Co-authors contribute additional observing system (Met Office, P. Jermey (Met Office), and integral source of feedback and T. Cram (NCAR), S. Worley (NCAR) adjustments and reanalyses feedback J. Davie (Met Office), S. Mahmood collaboration to ICOADS in keeping the which then can be included as subsidiary (Met Office) dataset in tune with current observational The International Comprehensive records linked to the core R3.0 records. procedures and instrumentation, as well Ocean-Atmosphere Data Set (ICOADS) UERRA (Uncertainties in Ensembles The process and procedure to do so as new sources of marine climate data. Release 3.0 (R3.0) brings into operational of Regional ReAnalyses) is an EU- will be outlined. Uniquely, ICOADS as production new technical features and funded project that provides high- Decisions in the SOT have direct impacts a foundational observation dataset is user-driven innovations that make it resolution reanalyses over Europe, on the Near-Real-Time product as well one of the first, if not the first, open more data rich as both an input for and together with measures of uncertainty as other aspects of data collection and access archive to capture significant output from reanalysis products. This in those reanalyses. As a part of processing. Finally, we will also report components of the data life cycle. In this presentation will highlight the suite of UERRA, the Met Office is running on progress towards establishment case, the ICOADS data life cycle includes product types and data access methods a single high-resolution reanalysis of ICOADS as a Centre for Marine- routine new releases that add new data available from NCEI, NOAA ESRL/ and a lower-resolution ensemble of Meteorological and Oceanographic sources and coverage throughout the full PSD, and NCAR, followed by a detailed reanalyses. These reanalyses cover Climate Data (CMOC), within the new period of record (over 300 years), and is description of the new features included the satellite era (1979-present). They WMO-IOC Marine Climate Data System furthermore updated with modern data in R3.0 that further support and augment assimilate a wide range of satellite data (MCDS), which is anticipated to facilitate on a monthly basis. reanalysis studies. (radiances, atmospheric motion vectors, further longer-term improvements This is supported by preservation in a scatterometer winds and ground-based in the effective management and The R3.0 data and metadata long-term archive that freely distributes GPS measurements). stewardship of marine and near-surface characteristics will be described in a the data and related products and oceanographic data internationally. companion presentation. By using new The spread in the ensemble can be enables numerous flexible pathways IT infrastructure and IMMA1 format taken as a measure of the uncertainty to access the data. Finally, as will be enhancements, R3.0 now has new in the reanalysis. It is to be hoped that described in this presentation, an ocean-based data parameters, observing improvements in the observation network operational system has been developed system bias adjustments developed and over time lead to more reliable analyses to receive information back from the provided by experts whose contributions with smaller uncertainty. Here this data user community that captures create improved climate records, and hypothesis is tested by comparing the the knowledge gained and makes it assimilation model feedback from ensemble spread for short periods run shareable with the next generation of reanalysis efforts. with and without satellite data. users.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 63 Section 2

assess some of the current techniques need of costly data retrievals. Besides selected 4 meteorological stations of Iran Improving velocity de-aliasing used or proposed with data from China, this data discovery mode there is the with diverse climates, varying from arid method for radar data representing various precipitation possibility to download data. The OFA to very humid climate, These stations assimilation regimes. serves feedback data from the ERA- include Ahvaz, Kerman, Sharekord and 20C, ERA-Interim and ERA5 reanalysis. Bandar Anzali. The closest grid points of Author Guangxin He An overview will be presented as well CRUTS3.23 to each station coordinates Affiliation NCAR Introduction to the Copernicus’s as a real test case to demonstrate the was chosen for a statistical comparison observation feedback archive Co-authors importance of feedback data. analysis. To evaluate the performance Guangxin He (NCAR and Nuist), Author Gionata Biavati of the temperature and precipitation records at the understudy stations, the Juanzhen Sun (NCAR), Zhuming Ying Affiliation ECMWF Investigation of the accuracy of (NCAR) Taylor diagram and Nash-Sutcliffe model Co-authors Climate Research Unit (CRU) efficiency coefficient (EF) were used. Radar observations play an increasingly G. Biavati (ECMWF), H. Hersbach temperature and precipitation The performance of each variable was important role in numerical weather (ECMWF) Time-Series in several climatic also graphically represented through prediction (NWP) where real time Within the Copernicus Climate Change zones of Iran scatter plots of grid box values and forecasts of actual storms, initialized Service (C3S), one task is the provision observed record data at the selected by current data are within reach. The Author Mansoureh Mansoureh of easy access to observations that were stations. The results indicate that the Doppler radar observation network in Affiliation Climatological Research ingested in global reanalysis as produced CRU precipitation time series performs China, CINRAD (China Next Generation Institute (CRI) at ECMWF. Key feature is the inclusion well in Kerman, Shahrekord and Ahvaz Weather Radar), is one such network that of feedback information on how such Co-authors with strong correlation coefficient and could provide much needed observations observations were used, like how well Mansoureh Kouhi (Ph.D Student of low values of RMSE. Indeed, very high of precipitation, wind, and hail in near they fitted the analysis products before Agricultural Meteorology, Department of agreement between observations and real time. Radar data assimilation at and after assimilation,and estimates on Faculty of Agriculture, Ferdowsi each grid points value were found. the convective scale has the potential biases and data quality. University of Mashhad), Hossein Sanaei to improve the prediction of hazardous Nejad (Associate Professor, Department However, it was found that the amounts weather. At present, the 3D-Var, 4D-VAR This service will be provided by the web- of Faculty of Agriculture, Ferdowsi of CRU precipitation have been and EnKF techniques are most widely based Observation Feedback Archive University of Mashhad), Mohammad underestimated in most of the stations used in operational NWP. Many NWP (OFA) as an integral part of the Climate Amini( Professor, Department of located in the coastal areas of the models (e.g. WRF, VDRAS and GRAPES) Data Store (CDS) toolbox,with the aim is Statistics, Faculty of Mathematics, Caspian Sea including Rasht, Gorgan including regional module arms to to reach a wide range of reanalysis users. Ferdowsi University of Mashhad) and Bandar Anzali. It means that the assimilate radar data observation. In addition it forms a relevant monitoring complex topography of this region have tool for the reanalysis production, itself. The lack of an adequate network of not been taken into account during the The quality of the radar data will affect The web interface provides a quick weather stations in Iran especially in interpolation process of precipitation in the results of assimilation. Two of the tree-based overview on the complete deserts and mountainous regions is this climate dataset. issues in the use of Doppler radial observing system on one single page. the most important limitation in the velocity are the data quality control of hydrological and climate change studies aliased velocities and noise. The volume Instruments or satellites can be selected for this country. Using the available of the data used requires substantial and time series of statistics on their gridded precipitation and temperature automation, and adequate accuracy. The usage can be plotted instantly from a datasetsis is the perfect solution to quality control must be robust. Here we previously created catalogue without the overcome this obstacle. in this study, we

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 64 Section 2

a responsible member. In a third stream, snow cover products to the development Observational Data from the newly digitized data from the historic Observations for Reanalyses of a global station data metadatabase. The Marine Data Climate Centre of ship journal archive of the DWD are – Lessons from ERA-CLIM2 data generated feed into global repositories Deutscher Wetterdienst continually added to the archive as well and serve future reanalysis projects. as other available sources. All incoming Author Stefan Brönnimann Author Axel Andersson data sets are routinely checked with a Affiliation University of Bern Observations Processing for Affiliation Deutscher Wetterdienst sophisticated high quality control (HQC) Co-authors CMA 40-year atmospheric Co-authors procedure that performs several formal S. Brönnimann1 and ERA-CLIM2 WP3 A. Andersson (DWD), L. Gates (DWD), and meteorological checks on the data. team reanalysis (CRA-40) H. Otten-Balaccanu (DWD), M. Schulz As part of the contributing member Global dynamical reanalyes of the Author Lipeng Jiang (DWD) role in the GCC, German VOS data atmosphere and ocean fundamentally Affiliation National Meteorological undergoes an additional manual quality The Marine Data Climate Centre of rely on observations, not just for the Information Center, CMA control. In the light of the evolution of Deutscher Wetterdienst maintains an assimilation (i.e. for the definition of the Co-authors the WMO MCSS into the new Marine extensive climatological archive of state of the Earth-system components), Lipeng Jiang (National Meteorological Climate Data System (MCDS) new forms quality controlled marine surface and but also in many other steps along the Information Center, CMA), Zhiquan Liu of data management are implemented, atmospheric observations. Apart from production chain. Observations are (NCAR), Chunxiang Shi (National such as flexible data access and product recent data, the archive consists of a used to constrain the model boundary Meteorological Information Center, CMA), generation. Standardized data formats large amount of historic data ranging conditions, for the calibration of Zijiang Zhou (National Meteorological and metadata handling is essential back to the mid-19th century. Data transfer function or retirevals, for error Information Center, CMA), Tao Zhang to allow data exchange with external from the archive is used in a variety determination of observations, and for (National Meteorological Information partners, e.g. ICOADS. of application, such as operational the evaluation of data products. Center, CMA), Jie Liao (National climate monitoring and international The presentation will give an overview This requires major efforts on the side Meteorological Information Center, CMA), data exchange in the context of the of the marine data management at of observations, including data rescue Zhisen Zhang (National Meteorological WMO Marine Climatological Summaries DWD that includes all stages from data (for historical observations), data Information Center, CMA), Minyan Wang Scheme (MCSS). collection by the port meteorological management (including metadatabases), (National Meteorological Information officer to data quality assurance and Center, CMA), Shuang Yao (National Several data streams are combined into compilation and quality control, and error aggregating into marine data products. Meteorological Information Center, CMA), a consolidated archive with a constantly assessment. Such efforts took place Current developments such as new Lijuan Cao (National Meteorological increasing data amount. Real-time GTS within the ERA-CLIM2 project, aiming routines for automatic and manual Information Center, CMA), Kaixi Hu data from ship, buoys and other marine at providing a better observational basis HQC, migration of the data archive to a (National Meteorological Information measurement platforms are automatically for reanalyses. The work on observations high performance data base system to Center, CMA), Zhe Chen (National stored in an interim database and are ideally is one cycle ahead of the facilitate user access will be highlighted Meteorological Information Center, CMA), consolidated in near real-time for the generation cycle of reanalyses, allowing as well as present and planned data Hui Jiang (National Meteorological archive. Secondly, Voluntary Observing them to make full use of it. products for a variety of applications. Information Center, CMA), Chenghu Sun Ship (VOS) data, which is collected by In this paper we describe the activities (National Meteorological Information the Global Collecting Centres (GCC), is within ERA-CLIM2, which range form Center, CMA), Qi Zhao (National injected in delayed mode into the archive. upper-air data rescue to satellite data Meteorological Information Center, CMA) In this context, DWD acts together with recalibration and from the generation of UK MetOffice as a contributing as well as

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 65 Section 2

CMA started global reanalysis efforts at the prepared observations will firstly Parts of the digitized and quality- the end of 2013 to produce CMA 40- being assimilated in a GFS/GSI-3DVar controlled data were handed over to On the use of CCI atmospheric year atmospheric reanalysis (CRA-40) based interim reanalysis (CRA-Interim) the International Surface Pressure data sets in future reanalyses extending back to 1979. As observations covering 10-years from 2007 to 2016. Databank (ISPD) and to the International assimilated in the NCEP climate forecast We also intend to present some initial Comprehensive Ocean-Atmosphere Data Author Rossana Dragani system reanalysis (CFSR) covering results of observation minus analysis and Set (ICOADS) in the last few years. Both Affiliation ECMWF from 1979 to 2014 and in the NCEP background from this pilot experiment. data sets are an important data source Co-author R. Dragani (ECMWF) operational global data assimilation for global and regional reanalyses of the system (GDAS) archive from 2014 to atmosphere such as the 20th Century The Climate Change Initiative (CCI) was present were collected, the basic idea On the benefit of newly digitized Reanalysis of NOAA-CIRES (20CR). established in 2009 by the European for CRA-40 observations preparation is station data of the German 20CR in its latest version 2c covers Space Agency (ESA) with the aim of that, 1) use satellite radiances in CFSR/ Marine Observatory Hamburg to the period 1851-2012 and contains 56 exploiting their and third party satellite GDAS observation database directly; the reanalysis 20CR version 2c ensemble members. missions to generate new climate data 2) add more Chinese observations to records for 13 essential climate variables The quality of reanalysis of the CFSR/GDAS database for conventional Author Birger Tinz (ECVs). These freely available data sets atmosphere depends strongly on observations; 3) try to use the latest Affiliation Deutscher Wetterdienst for the atmosphere, land, ocean and the availability of quality-controlled reprocessed AMV and GPS-RO cryosphere are designed to meet the Co-authors observations in all parts of the world. In observations from various organizations. B. Tinz (DWD), G. Compo (Uni Colorado, needs and requirements of the climate particular, historical observations from and reanalysis communities. At this point, the presentation will focus NOAA), L. Slivinski (Uni Colorado, data-sparse remote or overseas regions on the processing of conventional NOAA), A. Andersson (DWD), L. Gates have a significant impact on the quality A Climate Modelling Users’ Group observations, AMV and GPS-RO. (DWD) of the reanalysis. Individual phenomena (CMUG) was also established within the CCI to bring the modelling perspective Chinese radiosonde, SYNOP, Ship/Bouy Deutscher Wetterdienst (DWD, German can be resolved with much more detail to the CCI community and to assess the observations and aircraft observations Meteorological Service) holds in its through additional data. collected from various data sources suitability of the CCI data sets in several Hamburg branch office an archive of The presentation will show the potential were firstly converted to “PrepBUFR” user applications, including reanalysis. several collections of original historical benefit of newly digitized data from format (same as CFSR observations) As part of the CMUG activities, various world-wide weather records from ships, historic overseas stations of the and then merged to CFSR/GDAS CCI ECVs were assimilated in several 1500 land stations in many parts of Deutsche Seewarte. Data from China, database. In order to perform online experiments using the ECMWF data the world, as well as so-called “signal Korea and the tropical Pacific will be quality control (QC) using NCEP GDAS assimilation system. stations” (about 160) at the coasts of the included in future versions of 20CR QC procedures, a “PrepBUFR” to the German Bight and southern Baltic Sea. and are expected to have a significant The aims of these experiments were to so-called NCEP DUMP BUFR conversion The archive originates from the Deutsche impact on the reanalysis fields. The determine the impact of the CCI ECVs tool were developed based on the python Seewarte (German Marine Observatory), results provide motivation for continuing on their analysis and forecast equivalent, interface to NCEP BUFR library, and all which existed from 1875 to 1945 and was data rescue activities to further improve to assess the consistency among them, the merged conventional observations the predecessor organization of DWD in reanalysis products. and generally to establish their potential were converted to DUMP format which Hamburg. suitability for forthcoming reanalyses. is needed by GDAS QC procedure. A first study focused on ozone and The presentation will also introduce included a thorough assessment of the collection and processing of AMV several CCI ozone retrievals. The results and GPS-RO. As a pilot experiment,

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 66 Section 2 showed that these data sets produce a changes as well as the exchanges This requires a homogeneous and (small bias), and precision (high signal positive impact by generally improving between ocean, land, cryosphere, and stable sea level record. Such dataset is to noise ratio). One objective of the the quality of the ozone analyses atmosphere. The satellite altimeter produced within the Copernicus Climate Copernicus Climate Change Service compared to independent observations. sea level has been measured by Service (C3S). The main steps of the (C3S) is to provide improved global and Most of the assessed data sets are now different successive missions since altimeter production system will be regional reanalysis data that meet these assimilated in the Copernicus Climate 1993. More than 70 cumulated years presented. Then, the characteristics and requirements. Change Service ERA5 reanalysis, the of measurements have now been limits of the different products described In order to achieve this goal their inputs, ERA-Interim replacement. reprocessed with the DUACS (Data above (C3S, CMEMS) will be presented observations, must be accurate, stable, Unification and Altimeter Combination in order to help the ocean and climate In a successive study, ozone, aerosols and available over long time periods. System) production system. community on their optimal use for and GHG data sets from CCI were Serving this need, the Fidelity and validation, assimilation activities as well jointly assimilated to determine their In addition of the altimeter instrument, uncertainty in climate data records as scientific studies. suitability to constrain atmospheric the sea level estimation strongly relies from Earth Observations (FIDUCEO) composition reanalyses, like those run by on other complex systems such as orbit project reassesses satellite observations the Copernicus Atmosphere Monitoring solutions, reference fields and oceanic/ Preparing HIRS radiances as of different instruments, in terms of Service, and to assess the consistency atmospheric geophysical corrections. input to Reanalysis within the determine the uncertainty, recalibrating between them. In this contribution, we During the past 6 years (2011-2017), the Copernicus Climate Change the measurements, and increasing the will present a selection of the results ESA Sea Level Climate Change Initiative accuracy. obtained in the above-mentioned studies has been the opportunity to improve the Service Within the presented study, we and discuss the suitability of these ECVs homogeneity and stability of the altimeter Author Timo Hanschmann demonstrate an undertaking of preparing for future reanalyses. sea level record. Affiliation EUMETSAT input satellite data for reanalysis in Today, the altimeter sea level is used Co-authors a research-to-operations mode. A On the Use of Sea Level Climate for two main kinds of applications: (i) T Hanschmann (EUMETSAT, Darmstadt, Fundamental Climate Data Record Data Record (CDR) for The retrieval of mesoscale signals in the Germany), G Holl (University of Reading, (FCDR) of the High Resolution Infrared Reanalyses Evaluation context of ocean modeling and analysis reading, UK), V John (EUMETSAT, Radiation Sounder (HIRS) is prepared, of the ocean circulation at global or Darmstadt, Germany), R Roebeling based on the latest science including Author Jean-Francois Legeais regional scale. This requires the most (EUMETSAT, Darmstadt, Germany), metrological principles. This means Affiliation CLS accurate sea level estimation at each J Schulz (EUMETSAT, Darmstadt, not only revising the calibration and time step with the best spatial sampling investigating inter-satellite biases, but Co-authors Germany) of the ocean. Such dataset is produced also determining all the associated JF Legeais (CLS), Y. Faugère (CLS), within the Copernicus Marine Service Availability of operational satellite uncertainties. G. Taburet (CLS), MI. Pujol (CLS), G. (CMEMS) (previously distributed by observations on a multi decadal time Larnicol (CLS), B. Meyssignac (LEGOS) In this presentation, the focus is put on AVISO). (ii) The monitoring of the long- scale leads to an increased use of the very first instruments that have been term evolution of the sea level for climate them in reanalysis and climate studies, Sea level is a very sensitive index of rarely investigated until now. The time applications and the analysis of Ocean/ e.g., for the investigation of climate climate change and variability. Sea level series of HIRS on board of NIMBUS-6, Climate Index (such as the global and trends and feedbacks. However, to integrates the ocean warming, mountain TIROS-N, NOAA-6, and NOAA-8 is regional Mean Sea Level evolution). detect and evaluate climate trends and glaciers and ice sheet melting. Accurate analysed and their stability and variability monitoring of the sea level is required feedbacks, the time series need to have a high temporal consistency, accuracy is presented and compared to those of to better understand its variability and the new and more stable instruments,

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 67 Section 2 such as on METOP-A and METOP-B. We also attempt to geospatially visualize reanalysis products. Climate applications This research contributes to the WMO Further, C3S builds on the experience this increase in weather station density require high accuracy satellite initiative Sustained and Coordinated and achievements of FIDUCEO. Thus, versus accuracy improvement, and observations or at least a quantification Processing of Environmental Satellite this presentation will show results of quantify the relationships between and correction of effects due to changes data for Climate Monitoring (SCOPE- FIDUCEO on the increased accuracy of distance, density, and accuracy. Finally, in the characteristics of satellites CM) project No. 6: Inter-calibration of HIRS radiances due to revised calibration we propose a method to optimally and sensors that appear during their imager observations from time-series and in depth uncertainty analysis. choose locations for future weather operational lifetime. of geostationary satellites (IOGEO), stations in such a way that would which aims at establishing spatially This presentation addresses a common maximize gained accuracy improvement. and temporally homogeneous radiance re-calibration approach that has been Quantifying The Improvement data from all geostationary satellites. applied to the imagers’ infrared and In Reanalysis Accuracy Due The recalibrated radiances are used to water vapour channels (at ~11 μm and To Hobbyist Weather Stations Re-calibration of Infrared and derive products such as clear and all sky ~6 μm, respectively) on both EUMETSAT Water Vapor channels of imagers radiances as well as Atmospheric Motion Author Khaled Sharif and JMA geostationary satellites, i.e., on EUMETSAT and JMA Vectors that can be assimilated into VISSR/JAMI/IMAGER on the GMS/ Affiliation ArabiaWeather Inc models used for reanalysis. In addition, geostationary meteorological MTSAT series and MVIRI/SEVIRI on the Co-authors the data are also used to derive Global satellites METEOSAT series. Data from the Infrared K Sharif (ArabiaWeather), M Mansour Climate Observing System Essential Atmospheric Sounding Interferometer (ArabiaWeather) Author Viju John Climate variables such as sea and land (IASI), Atmospheric Infrared Sounder EUMETSAT surface temperature, cloud properties, Affiliation (AIRS) and High Resolution Infrared ArabiaWeather has, over time, created upper trophospheric humidity etc. a large network of hobbyist weather Co-authors Radiation Sounder (HIRS/2) were used as Viju John (EUMETSAT), T. Tabata (JMA), stations distributed to volunteers around references for recalibration. R. Roebeling (EUMETSAT), F. Ruethrich the Middle East and North Africa region, Recent developments in the (EUMETSAT), T. Hewison (EUMETSAT), The referencing was performed at the in an effort to cover areas that are European Climate Assessment & J. Schulz (EUMETSAT) HIRS/2 channel’s spectral response that too distant from traditional sources of shows the best fit to the instruments in Dataset observational data. Geostationary meteorological satellites geostationary orbit. To keep the time Author Gerard van der Schrier Due to the sparsity of existing weather have been observing the Earth for series of reference measurements the Affiliation Royal Netherlands stations, the region makes for a good more than 40 years to support weather same, AIRS and IASI spectra were Meteorological Institute case study regarding the improvement in nowcasting and forecasting and other convoluted using the HIRS/2 spectral reanalysis accuracy gained by increasing environmental applications. Due to their response, which revealed very small Co-authors the number of weather stations at the long observation period, good temporal uncertainties as compared to directly G. van der Schrier (KNMI), E. van den surface level. In this paper, we attempt to sampling and spatial coverage, these using hyper-spectral sounder spectra Besselaar (KNMI), C. Photiadou (KNMI), quantify the accuracy improvement versus observations could be of tremendous convoluted with the spectral response A. Squintu (KNMI), R. Cornes (KNMI, the amount of weather stations added, value for climate studies, such as on from the geostationary instruments. CRU), A. Klein Tank (KNMI), G. Verver and also quantify the plateau effect that cloud properties and their impact on the Collocated geostationary counts and the (KNMI) occurs once we reach a saturating point global radiation budget. reference radiances are then regressed to derive re-calibration coefficients for The European Climate Assessment in terms of stations added. They are also shown valuable for each geostationary instrument. & Dataset aims to provide daily assimilating into Numerical Weather meteorological station-baseddata and Prediction models used for generating

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 68 Section 2 analysis for scientific research in and Even today, the central Congo Basin is Using the relative entropy of each buoy used an individually calibrated outside the climate sciences. An important currently represented by only a few rain the ensemble with respect to a temperature probe, instead of one picked contribution to this activity is the E-OBS, gauges, limiting climate both retrospective climatolological distribution shows from a batch calibration. with is the gridded data set with daily analysis and forecasts across the Congo clearly the time and space variation of Note the first two improvements (but maps of temperature,precipitation and Basin. Here we present the historical the reanalysis skill. The dominant factor not the third) are now standard on most pressure for Europe, based on ECA&D. context in which measurements were inthe analysis skill is the availability of drifting buoys. In addition, some of these In this presentation the latest changes to made by La régie des plantations de la nearby observations for assimilation – buoys were also fitted with two digital the ECA&D station coverage and products colonie (REPCO) and the Institut National making new observations available by probes, one in the buoy hull around 17 are shown. Emphasis will be on the newly d’Etudes Agronomique du Congo systematic data rescue can generate cm depth, and another located around 45 introduced Quality Control procedures and Belge (INEAC), covering six decades large improvements in 20CR. cm depth (as part of a conductivity and homogenization of daily temperature data. (1901 – 1960). We discuss the rationale temperature sensor). behind the establishment of various measurement stations, the protocols used Revisiting the data record of This configuration, with two accurate Recovering (eco-)climatological as well as instrumentation. Our analysis High Resolution Sea Surface sensors, offered near-optimal horizontal data from Belgian colonial provides contextual information critical Temperature drifting buoys: and temporal collocation. The data archives. to the proper valorization and possible implications for climate records from the two sensors, located at interpretation of data collected within different depths, were revisited with the Author Innocent Banzi monitoring the COBECORE project. help of reanalysis products as a proxy for Ngulu-kulu Author Paul Poli the sea-state. The differences between Affiliation Ghent University Affiliation Météo-France the two sensors can be reduced from Co-authors Reducing uncertainty by data 0.21 K RMS to 0.06 K RMS after retaining rescue Co-authors Innocent Banzi Ngulu-kulu (Ghent P Poli (Centre de Météorologie Marine, only the situations that likely correspond University), Kim Jacobsen (Xylarium, Author Philip Brohan Météo-France) to well-mixed SST. Accounting for Royal Museum for Central Africa), Tom de individual buoy biases, the differences Affiliation Met Office Hadley Centre Mil (Xylarium, Royal Museum for Central Between 2012 and 2015, the EIG are further reduced to 0.02 K RMS. Africa), Jan Van den Bulcke (Laboratory Co-authors EUMETNET Operational Service This would tend to suggest a strong of Wood Technology), Hans Verbeeck Philip Brohan (Met Office Hadley Centre) for surface marine observations relationship of the relevance of SST (CAVElab, Ghent University), Koen (E-SURFMAR) and European partners The Twentieth Century Reanalysis measurement with depth and sea-state, Hufkens (Richardson Lab, Harvard funded and deployed drifting buoys (20CR) has demonstrated the power of and the importance of these factors University) equipped to measure High Resolution reanalysis as a tool for inferring long- when using in situ SST data for climate Sea Surface Temperature. The HRSST term climate variability and change. monitoring. Another result concerns The COBECORE project (http:// referred to three major improvements In particular, it is an effective user potentially the temporal stability of cobecore.org) aims to establish baseline as compared to standard practices at of the limited historical observations buoy SST data. The HRSST buoys were climatological measurements by the time. First, the positioning accuracy record, adding value to the available first calibrated individually in certified valorizing climatological legacy data, was increased, thanks to GPS instead observations. A key virtue of 20CR is laboratories. crucial for reanalysis. This lack of long- of Argos. Second, the temperature that it is an ensemble product, and the term (historical) climatological data was transmitted and reported at higher Three buoys were recovered and the distribution across the ensemble is an leaves the central Congo Basin spatially resolution, 0.01 K instead of 0.1 K. Third, temperature sensors were brought invaluable measure of uncertainty. and temporally under-represented. back to a certified laboratory in 2016.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 69 Section 2

Comparing the initial laboratory results can trigger a sudden increase in Heat Flux (LHF), Sensible Heat Flux (SHF) This orbit allowed for the collocation of with those of 2016, a temporal drift of chlorophyll-a (Chl-a) concentration in the and enthalpy are observed in the right measurements with other scatterometers about 0.01K/year is found for each of ocean, after they pass over the region. In and upper side during the passage of as well as an ability to sample diurnal the three buoys. These results from this study, changes in Chl-a and physical MADI. Keywords: Phytoplankton bloom, signals. In the Modern-Era Retrospective so few buoys cannot be claimed to fields after the passage of cyclone MADI Bay of Bengal, Chl-a, ROMS, NChlPZD, analysis for Research and Applications, be significant. However, if confirmed, are studied using various datasets. SHF, LHF, Enthalpy Version 2 (MERRA-2) reanalysis, the these results would have applications Maximum wind speed recorded during scatterometry record began with on the use of in situ SST buoy data the cyclone MADI is about 120 km/h. the ESA European Remote Sensing as a reference, without any temporal The effective use of (ERS) scatterometer on 5 Aug 1991 A significant increase in Chl-a and drift correction, for the calibration and scatterometer winds in current and continued through today with primary productivity are observed after validation of satellite data and to monitor and future GMAO reanalysis the EUMETSAT Metop Advanced the passage of MADI. In the vicinity the climate. Scatterometer (ASCAT). RapidScat, of cyclone track, Chl-a concentration Author Mohar Chattopadhyay however, was not used in the MERRA-2 exceeds 2 mg/m3 and net primary Affiliation Sceince Systems and system as development had been productivity reaches 2000 mg/C/m2/day. Simulating Episodic Applications Inc./GMAO, completed prior to the beginning of its Deepening of mixed layer depth (MLD) Phytoplankton Bloom Induced NASA Goddard Space data record. In this presentation, the and rapid cooling of SST occurred during by Cyclone MADI in the South- Flight Center RapidScat ocean vector winds will be the cyclone. western Bay of Bengal Co-authors compared to MERRA-2, both in terms of Cyclonic eddies are also formed over M. Chattopadhyay (Science System and the analysis fields and in the context of Author Riyanka Chowdhury the bloom region, which are responsible Apllications Inc. Lanham, MD, USA/ its global observing system, to assess Affiliation Indian Institute of for enhancing the bloom events. Vertical GMAO, NASA Goddard Space Flight the viability of using the data in future Technology Kharagpur, movement of nutrient rich water from Center, Greenbelt, MD, USA) and W. reanalysis systems developed by the WestBengal, India sub-surface layer due to up-welling McCarty (GMAO, NASA Goddard Space Global Modeling and Assimilation Office Co-authors and deep mixing led to the bloom in the Flight Center, Greenbelt, MD, USA (GMAO) at NASA Goddard Space Flight Riyanka 1 Roy Chowdhury 1 (Center for south-western BoB after the passage of Center. Oceans, Rivers, Atmosphere and Land cyclone MADI. The simulation of Chl-a Scatterometer-derived near-surface Sciences, Indian Institute of Technology and drop of SST are conducted with the ocean vector wind retrievals provide Kharagpur, India, 1), Arun 2 Chakraborty daily forcing of winds and surface net global measurements complementary 2 (Center for Oceans, Rivers, Atmosphere heat flux in three-dimensional Regional to the sparse conventional observing and Land Sciences, Indian Institute of Ocean Modeling System (ROMS) during system which primarily consists of ships Technology Kharagpur, India, 2), S the passage of the cyclone. and buoys over water surfaces. The Prasanna 3 Kumar 3 (CSIR-National RapidScat instrument was flown on the Idealized five component biogeochemical International Space Station as a quick Institute of Oceanography, Dona Paula, model NChlPZD (Nitrate, Chlorophyll, Goa-403 004, India 3) and low cost replacement of QuikScat Phytoplankton, Zooplankton and and as a continuation of the NASA The impact of the cyclone MADI on Detritus) is used for the simulation of scatterometry data record. phytoplankton bloom in the south- Chl-a along the passage of the cyclone MADI. Air-sea fluxes are analyzed using A unique characteristic of RapidScat was western Bay of Bengal (BoB) has been that it flew in a non-sun synchronous observed. In general, tropical cyclones weekly products before, during and after the passage of the cyclone. Higher Latent orbit at an inclination of 51.6 degrees.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 70 Section 2

different versions of the same series can Author Steven Pawson (UARS: 1991-1995); Sounding of the The EUSTACE daily LSAT be found even within the same collection, Affiliation NASA GSFC Atmosphere using Broadband Emission with usually no information on the Radiometry (SABER: 2000-onwards). dataset: A collection of 36000+ Co-authors modifications applied. For the post EOS-MLS period, the joint unique in-situ daily temperature S Pawson (NASA GSFC), K. Wargan NASA-NOAA Ozone Monitoring and series with inhomogeneities Within EUSTACE public collections (NASA GSFC), C. Keller (NASA GSFC), Profiling Suite – Limb Profiler (OMPS-LP) (mainly GHCN-D, ISTI, and ECA&D) W. McCarty (NASA GSFC), L. Coy identified instrument was launched on the Suomi- of daily maximum and minimum (NASA GSFC) NPP platform in 201x and is planned for Author Yuri Brugnara temperature observations, together with future platforms. This study will examine Affiliation University of Bern some additional dataset with restricted The Solar Backscatter Ultraviolet two aspects of these data pertaining to data policy, were merged. Duplicates Radiometer (SBUV) instruments on NASA Co-authors future reanalyses. First, the feasibility were removed by comparing the and NOAA spacecraft provide a long- Y Brugnara (Oeschger Centre for Climate of merging the EOS-MLS and OMPS- observations in each individual year of term record of total-column ozone and Change Research, University of Bern), LP instruments to provide a long-term each series with the data of the stations deep-layer partial columns since about S Brönnimann (Oeschger Centre for record that extends beyond the potential Climate Change Research, University located within a 200 km radius. 1980. These data have been carefully processed to extract long-term trends lifetime of EOS-MLS. of Bern) Moreover, an automatic quality control and offer a valuable resource for ozone If feasible, this would allow for long- algorithm was applied to all series. EUSTACE is a EU Horizon 2020 project monitoring. Studies assimilating limb- term monitoring of ozone recovery in a We also carried out an homogeneity whose goal is to produce daily estimates sounding observations in the Goddard three-dimensional reanalysis context. assessment, by using four different of surface air temperature since 1850 Earth Observing System (GEOS) data Second, the skill of the GEOS DAS in breakpoint detection algorithms (three across the globe for the first time, by assimilation system (DAS) demonstrate ingesting historical data types will be relative tests and one absolute test), combining surface and satellite data that vertical ozone gradients in the upper investigated. Because these do not and provide breakpoint locations for using novel statistical techniques. As troposphere and lower stratosphere overlap with EOS-MLS, use will be made each series. The final result is a quality- part of this, tens of thousands of in-situ (UTLS) are much better represented than of system statistics and evaluation using controlled dataset of ca. 750 million data series were collected from various with the deep-layer SBUV observations. independent datasets. Impacts of using unique observations over the period providers. a complete ozone chemistry module will 1850-2015 that will be assimilated into This is exemplified by the use of retrieved also be considered. Surface in-situ observations are affected other EUSTACE products. ozone from the EOS Microwave Limb by several problems, in particular by Sounder (EOS-MLS) instrument in the inconsistencies in space and time in the The dataset will be publicly available in MERRA-2 reanalysis, for the period measurement procedures, and by the NetCDF format, with the exception of after 2004. This study examines the lack of information concerning these a small fraction of the data (due to the potential for extending the use of procedures. Moreover, human errors policy of data providers); nonetheless limb-sounding observations at earlier often contaminate the quality of the the information derived from this fraction times and into the future, so that future data in different ways. The absence (e.g., for the homogeneity tests) will be reanalyses may be more applicable to of an official global repository for public. the study of long-term ozone changes. meteorological observations means Historical data are available from NASA that often data undergo numerous Towards a Representation of instruments: the Limb Infrared Monitor of modifications by different users and the Stratosphere (LIMS: 1978-1979); the Vertically Resolved Ozone Upper Atmospheric Research Satellite Changes in Reanalyses

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 71 an upgraded system are presented. It with independent observations and other Section 3 – Methods is based on the most recent version An ocean reanalysis system reanalysis products such as SODA, of COSMO and incorporates model ECCO, GODAS. for reanalyses Author Changxiang Yan error and uncertainty in the lateral boundary conditions additionally to Affiliation Institute of Atmospheric Accounting for uncertainty in observation error. While the latter is Physics, Chinese Assimilation of HF radar ocean regional reanalyses – employing anymore accounted for using ensemble Academy of Sciences current data into NEMO-Nordic probabilistic verification for nudging as data assimilation technique, Co-authors using 4D EnVar model error is considered by employing C. Yan (Institute of Atmospheric Physics, identifying an enhanced Author Lars Axell stochastic perturbation of physical Chinese Academy of Sciences), J. Zhu configuration of the reanalysis Affiliation SMHI system for COSMO-EN-REA12 tendencies (SPPT). (Institute of Atmospheric Physics, Chinese Academy of Sciences), J. Xie Co-authors Further, a global ensemble of the new Author Lilo Bach (Institute of Atmospheric Physics, L. Axell (SMHI) German ICON model at a horizontal Affiliation Deutscher Wetterdienst Chinese Academy of Sciences) grid spacing of 40 km serves as Baroclinic eddies in the ocean are at Co-authors perturbed lateral boundary conditions. An ocean reanalysis system is developed least one order of magnitude smaller than Lilo Bach (Deutscher Wetterdienst), We show an extensive verification based on the hybrid coordinate ocean their atmospheric counterpart, being of Christoph Schraff (Deutscher of case studies against independent model (HYCOM). The ensemble optimal the order of ten km rather than hundreds Wetterdienst), Andreas Hense observations. Thereby, special focus is interpolation which estimates the of km. One consequence of this is that (University of Bonn) set to the research question of how an background error covariance matrix ocean current magnitudes and directions enhanced probabilistic representation by the season-dependent ensemble are often difficult to forecast, unless an In the framework of the FP-7 funded of the essential climate variables composed of the long-term model observation network of extremely high project Uncertainties in Regional of precipitation and screen-level ouputs is used. For in-situ ocean density is used. In practice, for currents Reanalyses (UERRA), a probabilistic temperature can be achieved. Initially, observations, the layer thickness, instead this can be accomplished using coastally regional reanalysis system based on we compare the uncertainty estimation of temperature and salinity profiles, is based High-Frequency radars measuring COSMO at a horizontal grid spacing reachable by accounting either for assimilated. the radial components of the sea surface of 12 km has been developed for the observation error, model error or LBC currents. European CORDEX-EUR11 domain (Bach uncertainty to obtain an estimate of their For the HYCOM, the model bias lead et. al, 2016). In the basic configuration, relative importance. to the inconsistency between the This poster presents results from the ensemble measures the reanalysis assimilation of in-situ observations and assimilation experiments using an uncertainty with respect to observation Then, choosing the production the assimilation of altimetry observations. ensemble-based variational data errors based on (ensemble) nudging as configuration of the system as Therefore, a new mean dynamical assimilation method, 4D EnVar. It is data assimilation scheme (Schraff, 1996). verificational reference, we demonstrate topography required by the altimetry shown that assimilation of HF radar the added value of combining as many data assimilation is obtained by the data greatly improves the surface Currently, a short test data set uncertainty sources as possible which assimilation of Argo into the HYCOM. currents in the model NEMO-Nordic comprising the years 2006 to 2010 and is preferable for probabilistic reanalysis in the Skagerrak, off the west coast of 21 ensemble members is produced The reanalysis experiment is carried out systems. Sweden. In it’s 3-D form, this assimilation which will be accessible from the in the Indian and Pacific oceans during method has earlier been used at SMHI ECMWF-Mars archive in the near future. 1993-2015. The resultant reanalysis for assimilation of SST, salinity and Here, the probabilistic capabilities of product is validated by the comparisons temperature profiles as well as sea ice, in

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 72 Section 3 both reanalysis work and for operational retrieval in capturing more accurate system. Experiments subsampling forecasts. This is the first time it is and complete vortex circulations in the Assimilation using large scale modern day observations to emulate applied on HF radar data. inner-core region of TC is believed to EOF error covariances historical data distributions are used to be the primary reason for its superior compare the performance of the EOF DA performance over direct assimilation of Author Daniel Lea to a more standard DA using a shorter Assimilation of Radar T-TREC- Vr data; for the latter, the data coverage Affiliation Met Office length scale Gaussian error covariance retrieved Winds with a New is much smaller when the TC is far away Co-authors model. Proposed Dynamic Constrainted and the cross-beam wind component is DJ Lea (Met Office), MJ Martin The EOF DA method is shown to difficult to analyze accurately with 3DVAR Hybrid En3DVar scheme for the (Met Office) work efficiently in a 1/4 degree global Short-term Tropical Cyclone method. In modern ocean data assimilation (DA) configuration and does a good job of Forecasting Near Landfall In order to improve the coupling and systems it is common to use relatively filling in the large data gaps. The system balance among wind and thermodynamic also allows a hybrid of the EOF and Author Yuan Wang isotropic and small length scale error state variables for TC system, especially standard covariance models. This has Affiliation Nanjing University covariance structures. The Met Office when only radar wind field is directly FOAM system, for example, produces the potential to allow us to formulate a Co-authors observed, a dynamic constraint based a global 1/4 degree analysis using the DA system which works well both in the Yuan Wang (School of Atmospheric on the steady momentum equations NEMOVAR variational DA system with historical and in the modern period. An Sciences and Key Laboratory of is incorporated into the WRF hybrid Gaussian error covariances with two initial assessment of the hybrid approach Mesoscale Severe Weather of Ministry ensemble-three-dimensional variational length scales: one shorter length scale, will be presented. of Education, Nanjing University, (En3DVar) DA system as a weak the first baroclinic Rossby radius, and Nanjing, China) constraint. one longer length scale of 400 km. Challenges in ERA5 data An extended Tracking Radar Echo by The flow-dependent ensemble These error covariances perform well assimilation state-of-the-art Correlation (TREC) technique, called covariance used in En3DVar helps with the modern ocean data distribution. system in the early satellite to update unobserved pressure and T-TREC technique, has been developed Such error covariance models are, period to retrieve horizontal circulations within temperature fields in a dynamically more however, inadequate for DA in historical tropical cyclones (TCs) from single consistent way compared to the static ocean and coupled reanalyses. Due Author Cornel Soci covariance; and the added dynamic Doppler radar reflectivity and radial to the historically inhomogeneous Affiliation ECMWF velocity (Vr) data. This study explores the constraint further produces more distribution of ocean observations, using accurate pressure within the typhoon. Co-authors assimilation of T-TREC-retrieved winds these small scale error covariances leads C. Soci (ECMWF), H. Hersbach (ECMWF), for two landfalling typhoons, Meranti With the help of both flow dependent to large areas of the ocean not being A. Horanyi (ECMWF), C. Peubey (2010) and Chanthu (2010), comparing covariance and the dynamic constraint, corrected and any analysis produced is (ECMWF), D. Schepers (ECMWF), to the direct assimilation of radar radial the new assimilation scheme produces not likely to be a globally realistic and A. Simmons (ECMWF) velocity. the best intensity forecast for the consistent one. ECMWF is currently producing the Assimilating T-TREC winds results in typhoon, in terms of the minimum sea We present an enhancement to ERA5 atmospheric reanalysis under the better TC structure and intensity analysis, level pressure and maximum surface NEMOVAR to use Empirical Orthogonal framework of the EU-funded Copernicus as well as the subsequent forecasts wind speed. Function (EOF) error covariances. Using Climate Change Service (C3S). ERA5 will for the track, intensity, structure and EOFs allows the DA to respect the global span the period from 1950 to near-real precipitation. The ability of the T-TREC scale teleconnections in the climate time and will replace ERA-Interim. ERA5

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 73 Section 3 employs a hybrid data assimilation system, correlation length scale become longer a coarse resolution ocean reanalyses The Oceanography Division of the Naval namely a 10-member ensemble4D-Var and vertical correlations broader. We and Earth system simulations, the Research Laboratory has performed two data assimilation (EDA), at 62km horizontal also present results showing that in the methodology proves able to shape the ocean reanalyses, a 17-year (1999-2015) resolution which generates a flow- 1980s, the quality control of the buoy global ocean heat content tendencies coupled ocean-sea ice reanalysis forced dependent background error covariance network in the southern hemisphere has according to the TOA estimates, without by NCEP CFS reanalysis fluxes and, in matrix (hereafter the background term) an important impact on improving the compromising the accuracy of the conjunction with the Marine Meteorology to be used in a deterministic 4D-Var data reanalysis quality. reanalysis itself. Division, a 7-year (2009-2016) coupled assimilation system at higher horizontal atmosphere-ocean-sea ice reanalysis. Spurious variability and under- (over-) resolution (31km). Constraining the global ocean estimation present in experiments with The reanalyses are built upon the The background term is a combination heat content through the use in-situ (no) data assimilation disappear current Global Ocean Forecast System of a climatological part and a flow- of CERES derived TOA Energy when EEI data are assimilated. Similarly, using the HYbrid Coordinate Ocean dependent one. The climatological part the surface warming hiatus present Model (HYCOM) and the Los Alamos of the background term depends on the Imbalance estimates without EEI data is significantly mitigated, Community Ice CodE (CICE). The ocean observation density, geographical area Author Andrea Storto inducing ocean warming at depths below model has 41 layers and an equatorial and model resolution. The ERA5 data 1500 m and slightly larger in the Southern resolution of 0.08° (8.8 km) on a tri-polar Affiliation CMCC assimilation system utilises the ECMWF Hemisphere, in qualitative accordance grid with the sea ice model on the same Integrated Forecasting System that was Co-authors with many other recent studies. grid that reduces to ~3.5 km at the North the operational model version in 2016 A Storto (CMCC), C Yang (CNR-ISAC), Pole. (though at lower resolution). S Masina (CMCC and INGV) Coupled high-resolution ocean- Sea surface temperature (SST), sea This version has been optimized to Clouds and the Earth’s Radiant Energy ice and ocean-atmosphere-ice surface height (SSH) and temperature- System (CERES) sensors onboard best use data provided by the current reanalyses at the Naval salinity profile data are assimilated into observing system. In particular, the TERRA and AQUA Earth Observation the ocean using the Navy Coupled climatological part of the background satellites in combination with other Research Laboratory Ocean Data Assimilation 3D Var system term has been generated based on space-borne sensors measure the Author James Richman (NCODA) every day. The SSH anomalies the recent data rich period. For the reflected shortwave radiation and are converted into synthetic profiles Affiliation Florida State University early satellite period (1979/1980s) over outgoing longwave radiation at the top of temperature and salinity prior to the southern hemisphere, however, it of the atmosphere (TOA). The TOA net Co-authors assimilation. appears challenging to obtain optimal radiation budget (also referred to as the J G Richman (Center for Oceanic Incremental analysis updating of reanalysis results. Although the EDA Earth’s energy imbalance, EEI) is stored Atmosphere Prediction Studies, Florida geostrophically balanced increments provides flow-dependent information, the in the oceans for the largest part. State University, Tallahassee, FL USA)E. is performed over a 6-hour insertion required changes in the background term J Metzger (Naval Research Laboratory, In this study, we propose a procedure window. For the coupled atmosphere- due to the sparser observing system are Stennis Space Center, MS USA)P J to assimilate global TOA radiation ocean-sea ice reanalysis, the same too large to be represented by errors of Hogan (Naval Research Laboratory, imbalance estimates from CERES in ocean-sea ice model configuration is the day alone. Stennis Space Center, MS USA)O M a coarse-resolution ocean reanalysis Smedstat (QinetiQ-North America, used. However, the prescribed CFS This presentation describes the system (2000-2014), based on a Stennis Space Center, MS USA) fluxes are replaced by coupling to the practical solution of recomputing the variational data assimilation scheme. climatological part of the background As a proof-of-concept in constraining term suited for this period. Horizontal the global ocean heat budget for use in

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 74 Section 3

NAVy Global Environmental Model while integrating for prediction. MRI- (NAVGEM) with 50 levels and T359 (37 Effect of assimilating sparse Evaluation of a Coupled CDA1 is applied to a coupled reanalysis km) horizontal resolution. weather observations in two Atmosphere-Ocean Data experiment for the period from November 2013 to December 2015. The coupling is done hourly using different ensemble reanalyses Assimilation System Reanalysis COARE 4.0 bulk fluxes on the ocean Author Philip Brohan in JMA/MRI Comparison of the reanalysis result with exchange grid. Following the lead of Japanese 55-year Reanalysis (JRA-55) Affiliation Met Office Hadley Centre Author Chiaki Kobayashi the Ocean Reanalysis Intercomparison indicates that the overestimation of the Project (ORA-IP), the monthly mean Co-authros Affiliation Meteorological Research sea surface latent heat flux found in upper ocean heat and salt content Philip Brohan (Met Office Hadley Centre) Institute JRA-55 disappears in the reanalysis of from the surface to 300 m, 700m and Co-authors MRI-CDA1. The system also effectively The Twentieth Century Reanalysis (20CR) 1500 m, the mixed layer depth, the Y Fujii (Meteorological Research suppresses the excess rainfall in the and the CERA-20C coupled climate depth of the 20°C isotherm, the steric Institute), C Kobayashi (Meteorological tropics in JRA-55, particularly in the reanalysis are both ensemble products sea surface height and the Atlantic Research Institute), T Ishibashi Intertropical Convergence Zone (ITCZ) in assimilating only surface observations. Meridional Overturning Circulation for (Meteorological Research Institute), Y the Pacific. They assimilate almost the same set of the two NRL reanalyses and the Simple Takaya (Meteorological Research atmospheric observations, but CERA These improvements of MRI-CDA1 over Ocean Data Assimilation (SODA 3.3.1) Institute), Y Takeuchi (Meteorological uses more information from each JRA-55 mostly stems from improvements eddy-permitting reanalysis have been Research Institute) observation, assimilating marine winds in of atmospheric physical schemes in the compared on a global uniform 0.5° grid. addition to the surface pressures used by JMA/MRI has developed a weakly- coupled model. We are also conducting The differences between the NRL 20CR. coupled Data Assimilation (DA) system, the uncoupled reanalysis using the MRI- coupled and uncoupled ocean CDA1. In the reanalysis, observational Comparison of the two ensembles, in MRI-CDA1, based on JMA’s operational reanalyses for the 7-year overlap period SST data are given instead of passing a time and place where observations systems. MRI-CDA1 is composed of are small. The differences in heat and oceanic data from the ocean to the coverage is sparse, demonstrates the global atmosphere 4-Dimensional salt content increase with increasing atmosphere in the coupled model. the relationship between individual Variational (4D-Var) system for numerical integration depth and salt content observations and analysis precision, weather predictions, NAPEX, the Although the difference of the coupled differences are largest in the Southern and shows the effect of the different global ocean 3-Dimensional Variational reanalysis from the uncoupled one Ocean. The differences increase when assimilation choices. (3D-Var) system for seasonal predictions, becomes much smaller than the either NRL reanalysis is compared to MOVE-G2, and the coupled atmosphere- difference from JRA-55, averaged error SODA. ocean model for seasonal predictions, and root mean square error against an In addition, large differences in the JMA/MRI-CGCM2. observation-based precipitation dataset equatorial circulation are found The coupled atmosphere-ocean model (CMAP) are still reduced in a large part comparing SODA to either NRL is adopted as the outer model of the of the tropics and subtropics. We also reanalysis. In the Indian Ocean, the atmospheric 4D-Var routine, although the found that the consideration of the ocean Equatorial Counter Current extends to uncoupled atmospheric model is used as surface currents in the estimation of the far to the east and the subsurface flow in the inner model. The analysis increments momentum fluxes across the sea surface the thermocline is too weak in both NRL of ocean temperature and salinity in the coupled system affects oceanic reanalyses. estimated by oceanic 3D-Var routine are circulation and near-surface wind fields. adopted to the outer (coupled) model

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 75 Section 3

0.25°x0.25° latitude/longitude grid using surrounding area with a gird spacing of 5 Evaluation of SST/SIC Boundary in-situ observations as well as satellite Is the regional reanalysis an km and the eastern part of the Asia with Conditions for the Next observations. alternative to the dynamical a gird spacing of 25 km, respectively. Japanese Reanalysis: JRA-3Q Use of the latter high-resolution SST/ downscaling to reproduce the The assimilated data are limited to the Author Masashi Harada SIC is expected to improve quality of past meso-scale atmospheric observations with the systems operated the reanalysis by better representing for more than about 60 years such as the Affiliation Japan Meteorological fields? influences of oceanic eddies on surface observations at the observatories Agency atmosphere aloft and by improving the Author Shin Fukui and the upper air observations with Co-authors accuracy of radiative transfer calculations Affiliation Tohoku University radiosondes, maintaining the long-term Masashi Harada (Japan Meteorological in satellite radiance data assimilation, Co-authors consistency of the analysis quality. This Agency) although MGDSST is not available before Shin Fukui (Tohoku University, experiment covers August 2014. The 1981 due to the lack of input satellite regional reanalysis is compared with Sea surface temperature (SST) and sea Meteorological Research Institute), data. In this study, we will present results two types of dynamical downscalings: ice concentration (SIC) are important Toshiki Iwasaki (Tohoku University), of preliminary evaluation of SST/SIC from one with time-integration uninterrupted input data in a reanalysis since they Kazuo Saito (Meteorological Research COBE-SST2 and MGDSST, focusing on over long-term and the other with are used as lower boundary conditions Institute, Japan Agency for Marine-Earth comparison with other widely used SST/ time-integrations over short-term and (BCs) for the atmospheric model and Science and Technology), Hiromu Seko SIC products. reinitializations without assimilation. data assimilation system. In the past (Japan Agency for Marine-Earth Science two Japanese reanalysis projects, i.e., The topics to be presented include long- and Technology, Meteorological The former type of dynamical JRA-25 (Onogi et al. 2007) and JRA-55 term trends and variabilities of global/ Research Institute), Masaru Kunii (Japan downscaling often fails to reproduce (Kobayashi et al. 2015), the used SST regional SST and polar SIC, as well as Meteorological Agency) synoptic-scale fields due to the and SIC BCs were derived from COBE- spatial distribution of their climatology. We investigate the potential of the internal variability. Assimilating only the SST (Ishii et al. 2005), which is a global In addition, we will also show results of regional reanalysis assimilating only conventional observations in addition to century-long objective analysis dataset preliminary experiments using the current the conventional observations as an the forcing from the lateral boundaries produced from only in-situ observations. version of JMA’s data assimilation system alternative to the dynamical downscaling successfully prevents the degradation, as a prototype for the JRA-3Q system which is more apparent in the lower In the next Japanese reanalysis JRA- to reproduce the past 3-dimensional to investigate the impacts of different fields. The latter type of dynamical 3Q (Japanese Reanalysis for Three high-resolution atmospheric fields for SST/SIC BCs on analyzed atmospheric downscaling underestimates the Quarters of a Century), we are currently the studies of the local responses to the conditions. Based on these results, we precipitation due to insufficient spin-up planning to utilize two SST/SIC products climate change and various meso-scale will discuss an appropriate period to accompanied by the reinitializations, by the Japan Meteorological Agency extreme events. combine two SST/SIC BCs for JRA-3Q although it captures the synoptic patterns (JMA): COBE-SST2 (Hirahara et al. production. A preliminary experiment of regional appropriately. 2014) for the period up to the 1980s and reanalysis is conducted with the NHM- MGDSST (Kurihara et al. 2006) for the LETKF, which consists of the Japan The regional reanalysis, where the period thereafter. COBE-SST2, which Meteorological Agency’s non hydrostatic simulated fields in the previous cycles is an improved version of COBE-SST, is model and the local ensemble transform are inherited as first-guess, reduces the produced on a 1°x1° latitude/longitude Kalman filter, applying the one-way underestimation of precipitation. The grid using basically in-situ observations double nesting to JRA-55. The inner configurations of this system are also only, whereas MGDSST is produced on a and outer domains cover Japan and its discussed from the perspective on long- term regional reanalysis.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 76 Section 3

The use of these meteorological at sites without historical records. The Modeling process chain of reanalysis datasets may solve uncertainty Post-treatment of the Climate Stochastic Model Output Statistical ECMWF reanalysis data to of data. In addition, phenomena such as Forecast System Reanalysis (SMOS) approach combined with meta- monitor rainfall evolution rainfall evolution require the analysis of (CFSR) daily precipitations Gaussian spatio-temporal (MGST) time series of ECMWF meteorological across the Great Lakes region random fields were used to this aim. Author HAJALALAINA Aimé reanalysis datasets and the development The SMOS approach used CFSR Richard of automated and reusable processing (Canada) precipitation as covariate and is Affiliation EMIT University of chains for monitoring rainfall evolution. Author Dikra Khedhaouiria based on two regression models, the Fianarantsoa We propose to formalize these Affiliation INRS-ETE logistic regression to deal with rainfall processing chains from modeling an Co-authors occurrence and the vector generalized abstract and concrete models based Co-authors Aimé Richard Hajalalaina (de Management linear model in a Gamma distribution on existing standards in terms of DK Khedhaouiria(Institut national de la et d’Innovation Technologique, Université framework for the intensity. Two skill interoperability (International Standard recherche scientifique, Centre Eau de Fianarantsoa, Madagascar), Angelo scores (Brier and continuous ranked Organization ISO and OGC Open TerreEnvironnement), AM Mailhot (Institut Raherinirina (Ecole Normale Supérieure, probability skill scores) showed that Geospatial Consortium). The use of these national de la recherche scientifique, Université de Fianarantsoa, Madagascar), estimated SMOS distributions had standards solves uncertainty of process. Centre Eau TerreEnvironnement), ACF Adolphe Ratiarison (4Laboratoire de la a better predictive power than the These processing chains modeled Favre(Univ. Grenobles Alpes, CNRS, IRD, Dynamique de l’Atmosphère, du Climat et climatology for both precipitation will be capitalized, and diffusible in IGE, Grenoble INP) de l’Océan, Université d’Antananarivo, occurrence and intensity. Madagascar), Thérèse Libourel (Université operational environments. Our modeling The most important challenge that many de Montpellier, Montpellier, France) approach uses work-context concepts. countries faces, including Canada, is Post-treated daily rainfall fields were These concepts need organization of to characterize historical precipitation then generated from SMOS daily In this paper, we propose a models of human resources, data, and process considering the low station density distributions with the use of the MGST process chain and knowledge-based of in order to establish a knowledge- in many of their regions. Reanalysis, random fields to ensure persistence meteorological reanalysis datasets that based connecting the two latter. This generated by Numerical Weather and spatial consistency in the series. help scientists, working in the field of knowledge-based will be used to solve Prediction methods assimilating past Selected climate indicators (e.g., annual climate and in particular of the rainfall uncertainty of meteorological reanalysis observations, are an attractive alternative cumulative wet day or spatial correlation) evolution, to solve uncertainty of spatial datasets resources for monitoring rainfall as they provide coherent, spatially and were estimated for post-treated, resources (data, process) to monitor evolution. temporally continuous meteorological observed and CFSR precipitation series. the rainfall evolution in an area. Indeed, fields for a specific period and domain. Comparisons between these indicators rainfall evolution mobilizes all research, However, reanalysis precipitations cannot helped identify the advantages of using various methods of meteorological be directly used as local estimates post-treated CFSR instead of CFSR, and reanalysis datasets processing are without post-treatments to correct bias highlighted which aspects of the daily proposed. The ECMWF (European Centre and other errors. post-treated sequences still need further for Medium-Range Weather Forecasts) investigations. meteorological reanalysis datasets The main objective of this study was available at present are voluminous and to post-treat the CFSR gridded daily heterogeneous in terms of spatial and precipitation over the Great Lakes region temporal resolutions (ERA-15, ERA-40, in Canada to provide spatially-coherent ERA-Interim and ERA-20C reanalysis). local estimates of precipitation series

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 77 Section 3

physics parameterizations to include than 50000 surface meteorological Preparing the NASA GEOS aerosol awareness in the microphysics Progress of CMA Land Data observation stations to produce surface model for future integrated and convection. Assimilation System (CLDAS) air temperature, surface pressure, surface humidity and surface wind Earth system reanalyses During the development cycle of Author Chunxiang Shi forcing data; As for shortwave radiation GEOS for future reanalyses we have Author William Putman Affiliation National Meteorological forcing data, we develop a new method supplemented the development/ Affiliation NASA/GMAO Information Center based on DISORT method, rewrite code reanalysis cycle with a ‘downscaling’ with parallel technology, use numerical Co-authors phase, running a higher resolution Co-authors forecast product and reanalysis data W Putman (NASA), M Suarez (USRA), development version of the model. Chunxiang Shi(National Meteorological to replace climatic background field; L Takacs (SSAI) Most of the production cost and a big Information Center),Zhiwei Jiang we also use three land surface models fraction of the development cost of a new (National Meteorological Information The NASA MERRA-2 reanalysis was (CLM3.5, CoLM and Noah-MP1-4) to gain reanalysis involves work on the data and Center), Xiao Liang(National executed at 50km resolution with a more steady and accurate land surface analysis system. For most systems the Meteorological Information Center), Tao a hydrostatic version of the GEOS simulation using assemble method. computing resources required to do a full Zhang(National Meteorological atmospheric model. This GEOS model (2) In high performance computing reanalysis are several times that required Information Center), Lipeng was built around the FV3 dynamical environment of China Meteorological to run the same period with a single Jiang(National Meteorological Information core co-developed at NASA and GFDL. Administration, we successfully develop instance of the free-running model. Center), Bin Xu (National Meteorological The physics in this version of the Information Center),Shuai Han (National CLDAS-V2.0 operation system with GEOS model underwent substantial We illustrate this global-downscaling Meteorological Information Center), Zhi the standard of China Integrated improvements from MERRA to begin approach and show its economic Zhu (National Meteorological Information Meteorological Information Sharing to address the issue of resolution feasibility with a 15-year experimental Center) System (CIMISS). Using EC-Flow awareness in the model physics from downscaling of the 50 km resolution software, we build Land Surface Forcing 200km down to 25km. MERRA-2 reanalysis using a 12 km CMA Land Data Assimilation System Data Fusion Sub-system, Land Surface resolution updated version of the GEOS (CLDAS) is founded by Multi-source Data Assemble Simulation Sub-system, As we look toward future reanalyses model. The technique, which we refer Fusion Team in National Meteorological Product Service and Distribution Sub- at the GMAO it is clear that computing to as “replay”, is similar to common Information Center, China Meteorological system, Product Evaluation Sub-system, capabilities will soon permit long nudging methods, but is particularly Administration. In May 2017, second and Product Monitor Sub-system. complete reanalyses at resolutions below suited for downscaling a global analysis version of CLDAS (CLDAS-V2.0) has 25km. In preparation for these systems In the end, we build the first operational that used incremental analysis updates. been put into operation In CLDAS-V2.0, and beyond the GEOS model is being land data assimilation system in China, It is shown that rather than tracking the we have three important progresses: adapted to provide a seamless scale- which has complete data acquisition, trajectory of the original reanalysis down (1)Through import and digestion, we aware modeling system from 200km to product production, product evaluation, to its shortest resolved scales, the most realize key technologies of land surface 2km. These updates include the latest product monitoring, product archiving, realistic results are obtained when only multi-source data fusion and analysis, nonhydrostatic FV3 dynamical core product distribution ability.(3) Based scales longer than ~600km are closely and transform these technologies from from NOAA/GFDL, updated topography on comprehensive consideration of reproduced, and the model is left to research to operation. and variance calculations, improved feedback from different research and generate the mesoscale. resolution awareness in the moist physics Based on previous survey, we choose operation users, we widen spatial that lead to convergence in model cloud STMAS developed by Xie as our coverage of our product and develop and radiative properties, and advanced method to fuse numerical forecast more land surface products including product and observations from more soil moisture, soil temperature, surface

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 78 Section 3 skin temperature, relative moisture of are assimilated into Common Land system for GRAPES_Meso model is time especially over 300hPa. Overall, the soil, surface air temperature, surface Model (CoLM) to estimate the soil established using the extended control the hybrid data assimilation has some pressure, surface humidity, surface wind, moisture in different layers. variable technique to implement a advantage over 3DVAR data assimilation. surface shortwave radiation, and surface hybrid background error covariance that A proposed forecast error inflation and precipitation. combines the climatological covariance water balance constraint are adopted in and ensemble-estimated covariance. The application of variational Our assessment shows that indexes the Ensemble Transform Kalman Filter data assimilation method on 2D of CLDAS-V2.0 products are better to reduce the analysis error and water Aiming at the problems of Ensemble- tides model for Malacca Strait than any other similar product in China. budget residuals. The assimilation results based data assimilation part of the It is encouraging that CLDAS-V2.0 indicate that the analysis error is reduced system include the degree of geostrophic Author Evie Hadrijantie Sudjono products has been used operationally in and the water imbalance is mitigated with balance between variables is reduced, Affiliation Marine Geological monitoring and forecasting of regional this approach. the analysis increment is not smooth Institute drought in Inner Mongolia, drought and the analysis increment is obviously Co-authors monitoring in Qinghai, and numerical smaller than the 3DVAR data assimilation, Evie H. Sudjono(1), Agus prediction research in Beijing. A new Study on the GRAPES Regional corresponding measures are taken to Setiawan(2)1Marine Geological Institute, land data assimilation system is under En-3DVAR Hybrid Data optimize and ameliorate the system. Agency for R and D of Energy and construction with the ability to assimilate Assimilation System Based on this, a single pressure Mineral Resources, Ministry of Energy soil moisture observations and satellite Author Lianglv Chen observation Ensemble-based data and Mineral Resources, Indonesia. brightness temperature. We are looking assimilation experiment is conducted [email protected] forward to build the best land data Affiliation Chongqing Institute of to ensure the Ensemble-based data Research Center, Ministry of Marine assimilation system in China Meteorological Sciences, Chongqing Meteorological assimilation part of the system is correct Affairs and Fisheries, Indonesia Service and reasonable, some localization scale sensitive tests of Ensemble-based data A variational data assimilation method Soil Moisture Assimilation Based Co-authors assimilation are conducted to determine was applied in this study in order to on a Modified ETKF Lianglv Chen(Chongqing Institute of the most appropriate localization scale. improve the result of 2D tides model of Author Guocan Wu Meteorological Sciences, Chongqing Malacca Strait. Several available tidal Meteorological Service),Jing On that basis, some hybrid data Affiliation Beijing Normal University measurement data were assimilated Chen(Numerical Weather Prediction, assimilation experiments are conducted. into the tides model by applying the Co-authors CMA),Jishan Xue(Chinese Academy of Results show that: it is the most conjugate gradient least square method. Guocan Wu (Beijing Normal University) Meteorological Sciences),Yu Xia(Chengdu appropriate to set the weight factors University of Information Technology) of ensemble-estimated covariance By comparing the results of data Assimilating observations to a land to 0.8 in the experiment. Contrasting assimilation model with forward model as surface model can further improve soil Based on the GRAPES regional to the 3DVAR data assimilation, the well as independent data (measurement moisture estimation accuracy. However, ensemble prediction system and geopotential height forecast of the hybrid data that were not used in the assimilation results largely rely on the Three-Dimensional Variational data assimilation experiments improve assimilation), some improvements were forecast error and generally cannot (3DVAR) data assimilation system that very little, but the winds forecast has obtained. This method can significantly maintain a water budget balance. In this are implemented operationally at the a slight improvement at each forecast reduce the over- and under-estimate study, shallow soil moisture observations numerical weather prediction center of results obtained by forward model. Chinese meteorological administration, an En-3DVAR hybrid data assimilation

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 79 Section 3

(IGBP) emissivity and the University Universität Bonn), S. Wahl (Hans-Ertel soil, vegetation and the atmosphere in Toward Assimilation of AHI of Wisconsin at Madison (UW) High Center for Weather Research, either direction, thus representing a fully Surface-sensitive Channels over Spectral Resolution Emissivity (UW_ Meteorologisches Institut der coupled terrestrial model approach. HSRemis) databases. Rheinischen-Friedrich-Wilhelms Land – A Quantitative In order to bring the model closer Universität Bonn) Assessment of Simulation By excluding the data during daytime, to observed precipitation, rain radar Accuracy over sandy land, Tibetan Plateau, or The representation of the diurnal reflectivity is assimilated into the with steep terrains, the brightness atmospheric component with a local Author Xiaoyong Zhuge to seasonal variability of the water temperature simulations generated cycle on small scales, needed for the ensemble transform Kalman filter Affiliation Nanjing University by the Community Radiative Transfer representation of surface and sub- (LETKF). Model (CRTM) with the ECMWF LST and Co-authors surface water flow in river catchments, To assess the added value of using such CAMEL_HSRemis database compare Xiaoyong Zhuge (School of Atmospheric is not well represented by current a soil-vegetation-atmosphere-transfer- very well with the Advanced Himawari Sciences and Key Laboratory of reanalyses. However, the interest in such model in ensemble mode, we evaluate Imager (AHI) observations statistically Mesoscale Severe Weather of Ministry data sets is increasing for hydrological precipitation and soil moisture with and instantaneously. This study suggests of Education, Nanjing University, Nanjing, and agricultural applications. respect to independent measurements that the AHI surface-sensitive channels China) and compare them to existing high- over land could be effectively assimilated Recent studies on land surface resolution atmospheric regional Simulations of surface-sensitive channels and contribute to improved numerical simulations for specific river basins, reanalyses as well as a pure dynamical from geostationary imagers over land weather predictions. with a finer grid spacing and driven by require accurate land skin temperature global reanalyses, show a significant downscaling experiment with the coupled (LST) and infrared land surface emissivity improvement in the representation of soil Te r r SysMP. (LSE). Compared with ground-based Ultra-high resolution reanalysis moisture and precipitation. The next step observations, large biases are found in for a river catchment would be to allow a feedback between Using lagged covariances to the European Center for Medium range the land surface and the atmosphere Author Clarissa Figura assimilate RAPID data Weather Forecasting (ECMWF) LST to take place, in order to achieve a analyses during daytime, over sandy Affiliation University of Bonn sustainable effect on the water cycle Author Christopher Thomas land and Tibetan Plateau, and areas Co-authors within the terrestrial system as a whole. Affiliation Department of with terrain height differences between C. Figura (Meteorologisches Institut der This study focuses on an ensemble of Meteorology, University 0.25° and 1-min topography resolutions Rheinischen-Friedrich-Wilhelms retrospective analyses of a short summer of Reading outside the range from -100 to 200m. Universität Bonn), A. Hense period for a catchment in the western Co-authors (Meteorologisches Institut der part of Germany. The Combined Advanced Spaceborne Keith Haines (Department of Rheinischen-Friedrich-Wilhelms Thermal Emission and Reflection We utilize a limited area model setup Meteorology, University of Reading), Universität Bonn), J. Keller (Hans-Ertel- Radiometer (ASTER) and Moderate at horizontal resolutions of 1 km for Irene Polo (Department of Meteorology, Center for Weather Research, Deutscher Resolution Imaging Spectroradiometer the atmosphere and 500 m for the University of Reading), Jon Robson Wetterdienst), C. Simmer (MODIS) Emissivity over Land (CAMEL) land surface and soil. The simulations (Department of Meteorology, University (Meteorologisches Institut der High Spectral Resolution Emissivity are based on the Terrestrial Systems of Reading) Rheinischen-Friedrich-Wilhelms database (CAMEL_HSRemis) have the Modeling Platform (TerrSysMP) which Universität Bonn), I. Thiele-Eich highest accuracy than the International has the capability to exchange the (Meteorologisches Institut der Geosphere-Biosphere Programme relevant state vectors between the Rheinischen-Friedrich-Wilhelms

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 80 Section 3

The motivation of this work is to between biased and nearby reference assimilate the observations of the AMOC Variational bias correction of observations (which are assumed to be made by the RAPID array at 26°N in Sea Surface Temperature unbiased). the Atlantic Ocean by modifying ocean observations First, the bias correction system was densities ‘upstream’ in the Labrador Sea. tested using the Lorenz 63 model. Under Previous studies have shown that the Author Daniel Lea most parameter regimes the VarBC AMOC is robustly sensitive to anomalies Affiliation Met Office scheme with observations-of-bias in the Labrador Sea which occur at a Co-authors worked well. However, when the true time lag of several years earlier. J While (Met Office), MJ Martin (Met bias was very small VarBC methods were The RAPID data will be assimilated into Office), DJ Lea (Met Office) found to slightly degrade the analysis a high-resolution (0.25°) global NEMO- relative to doing no bias correction. Observations can contain significant CICE model. Assimilating the data using Under all circumstances the VarBC systematic error. With Sea Surface a standard variational procedure with scheme including observations-of-bias Temperature (SST) data from satellites, a multi-year time window would be outperformed a VarBC scheme without biases arise due to both measurement impractical in such a model. Instead, these observations. and processing error, with a major source the aim is to use robust covariance of bias coming from uncertainty in the Second, we show results from applying information to make earlier increments atmospheric state used in the retrieval. the VarBC scheme in a realistic setting without the need for an adjoint. If unaccounted for, SST observation using the NEMO ocean model and The covariances are used to assimilate biases will propagate through any data NEMOVAR data assimilation framework. the lagged data on top of the trajectory assimilation procedure and contaminate The system is tested both for a period produced by an initial (standard) the analysis. We have developed a where reference data are plentiful, and variational assimilation. Using earlier Variational Bias Correction scheme for a period with only sparse reference assimilation increments should give (VarBC) for estimating observation bias data. Real data from the AQUA- better continuity to the circulation and in satellite measured SST. In the VarBC AMSRE, NOAA-AVHRR and NOAA- the heat transports, making the model system, observation bias is estimated by METOP instruments are bias corrected. more useful for coupled forecasting. appending the bias state to the control Reference data were taken from vector and modifying the observation drifting buoys and the ENVISAT-AATSR We will present the lagged covariance operator to remove the bias from the instrument. methodology and show results from observations before comparing to the simulation studies of an idealised system. The system is compared to the output state. We will also show the results of the of the Met Office’s current offline bias assimilation of RAPID data. Information from the innovations is used correction scheme. In these experiments to estimate both the bias and model the bias correction was found to reduce state. A term is included in the cost SST biases in the model background function comparing the bias field to relative to the reference data. ‘observations-of-bias’. This acts as an additional constraint improving estimates of the bias. In practise, observations- of-bias come from the difference

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 81 is an international effort to produce information on smaller spatial scales The importance of reanalyses as a Section 4 – Evaluation a comprehensive global atmospheric compared to established global basis for numerous applications in and intercomparisons circulation dataset spanning the reanalyses. As the production of regional geosciences, economics and other fields twentieth century which provides the reanalyses requires a high computational has significantly grown over the last of reanalyses dataset’s time-varying quality at 6-hourly effort, the quantification of the added decade. Therefore, a comprehensive temporal and 2° spatial resolutions. value compared to global reanalyses evaluation and intercomparison of and/or regional downscaling products reanalysis data sets is essential. A Comparison of Solar Radiation The solar radiation data for the duration is of high interest. In this study we Here, we quantify the added value of Data Measured at AEDB-UNDP of two years having eight daily values is investigate global and regional reanalyses regional atmospheric reanalyses (such Hawksbay Mast and 20th analyzed to get mean daily values. For with different horizontal resolutions and as COSMO-REA6) compared to their the selected location, the annual mean Century Reanalysis Version V2c model specifications with respect to their global forcing reanalysis products (e.g., daily solar radiation from Reanalysis near surface representation of wind and ERA-Interim, MERRA-2) with respect to Author Zia ul Rehman Tahir data is 259 W/m2 for the duration of two precipitation. monitoring climate and its variability. Affiliation Univeristy of Engineering years, which is much higher than surface and Technolgy Lahore, measured data, with mean bias error Especially for the European domain, To this end, we investigate the Pakistan (MBE) of 86 W/m2 and absolute mean several regional reanalysis data sets representation of climate indices in the Co-authors bias error (AMBE) of 87 W/m2 and root are available. A comparison with reanalyses in comparison to indices Muhammad Asim (Univeristy of mean square error of 30 W/m2. A bias independent observations allows for derived from observations. The set Engineering and Technolgy Lahore, correction method is used to develop the a quantification of the added value of of climate indices in consideration Pakistan), Nasir Hayat (Univeristy of solar resource potential map of Pakistan higher resolutions and/or convection- comprises simple measures such as Engineering and Technolgy Lahore, using long-term satellite data of ten permitting model specifications. The number of summer days or frost days but Pakistan) years. analysis is conducted with respect to also aggregated indices, e.g., heating/ the representation of near surface point cooling degree days. This paper presents a comparison of the observations for precipitation and wind. solar radiation surface measured data Added value of regional In order to assess the quality of the and 20th Century Reanalysis version 2c reanalyses: Precipitation and climate representation and thereby datasets. wind Added value of regional the added value of regional data reanalyses: Representation sets, we also quantitatively verify the The solar radiation data was measured Author Sabrina Wahl of climate indices indices derived from reanalyses with at AEDB-UNDP Hawksbay Mast Affiliation Hans Ertel Center for independent observations. (Karachi) under the Pakistan Wind Energy Weather Research Author Jan Keller Program for the duration of March 2009 Co-authors Affiliation Hans-Ertel-Centre for to May 2011 at a temporal resolution Weather Research of 10 minutes. Solar radiation data for S Wahl (Hans Ertel Center for Weather duration of two years from April 2009 Research, Climate Monitoring Branch), Co-authors to March 2011 was analyzed to find JD Keller (Hans Ertel Center for Weather J. D. Keller (Hans-Ertel-Centre for mean daily values of solar radiation. The Research, Climate Monitoring Branch) Weather Reserach, Deutscher annual mean daily solar radiation for Wetterdienst), S. Wahl (Hans-Ertel-Centre Regional reanalyses are a rapidly for Weather Reserach, University of Bonn) the site is 173 W/m2. The NOAA-CIRES emerging field of research. Such data Twentieth Century Reanalysis Project sets constitute a valuable source of

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 82 Section 4

The first was to use an updated set of regions of western and northern Iran Advances in ocean subsurface past observations that had been newly An assessment of the accuracy suffer from limited representative temperature analysis by IAP and corrected for biases (e.g., in XBTs). of ERA-Interim reanalysis stations. The XBT bias was corrected by CH14 its application in historical ocean precipitation in representing Using reanalysis precipitation datasets scheme, which is recommended by the heat content estimate observed precipitation in could be one of the possible solutions to XBT community. The second was to use overcome this obstacle; knowing that the Author Lijing Cheng co-variability between values at different different climates of Iran representativeness of these datasets has places in the ocean and background Affiliation Institute of Atmospheric Author Tayeb Raziei been already proved for many different information from a number of climate Physics, Chinese Affiliation Soil Conservation and parts of the world. Based on these facts, models that included a comprehensive Academy of Sciences Watershed Management the representativeness and performance ocean model. Co-authors Research Institute of ERA-Interim in representing Lijing Cheng (International Center for The third was to extend the influence (SCWMRI), Agricult precipitation amounts at 45 Iranian Climate and Environment Sciences, of each observation over larger areas, Co-authors synoptic stations distributed across the Institute of Atmospheric Physics, Chinese recognizing the relative homogeneity of Tayeb Raziei (Soil Conservation and country is herein examined. The spatial Academy of Sciences), Kevin E. the vast open expanses of the southern Watershed Management Research resolution of ERA-Interim dataset used Trenberth ( National Center for oceans. Then the observations were Institute (SCWMRI), Agricultural in this study is 0.125x0.125 in latitude and Atmospheric Research), John Fasullo ( also used to provide finer scale detail. Research, Education and Extension longitude. National Center for Atmospheric Finally, the new analysis was carefully Organization (AREO), Tehran, Iran), For each station, the closest grid point Research), John Abraham (University of evaluated by using the knowledge of Isabella Bordi (Interuniversity Consortium of ERA-Interim to the station coordinates St. Thomas), Tim Boyer (National Oceanic recent well-observed ocean states, but for the Physics of the Atmosphere and was chosen for a statistical comparison and Atmospheric Administration, National subsampled using the sparse distribution Hydrosphere (CINFAI), Rome, Italy) analysis. To evaluate the performance of Centers for Environmental Information), of observations in the more distant the considered dataset when compared Jiang Zhu (International Center for past to show that the method produces The lack of reliable and updated to the observed precipitation records Climate and Environment Sciences, unbiased historical reconstruction. precipitation datasets is the most at the considered locations we used Institute of Atmospheric Physics, Chinese important limiting factor in studying many Furthermore, ocean heat content (OHC) R-squared, the Nash–Sutcliffe model Academy of Sciences) climatological and hydrological topics change is a fundamental indicator of including climate change and temporal efficiency coefficient (EF), RMSE, A gridded ocean temperature dataset global warming. Accurate assessment variability of precipitation in many data Bias, B slope of the regression and the with complete global ocean coverage of OHC change is a key task and a key sparse areas around the globe. standardized RMSE indicators. challenge in the climate community. is a highly valuable resource for the The performance of the dataset was also Based on the IAP ocean temperature This is particularly valid for Iran that understanding of climate change and graphically represented through scatter analysis, we provide a new OHC estimate encompasses vast deserts and unsettled climate variability, evaluating climate plots of the established regression with an unbiased mean sampling error. hyper-arid climate areas (central-eastern models and ocean re-analyses. The between ERA-Interim and observation at The reconstructed OHC variability on Iran) that hinder establishing an adequate Institute of Atmospheric Physics (IAP) the selected stations. The results of the decadal and multi-decadal timescales network of rain-gauge stations required provides a new objective analysis of statistical indicators were represented (signal) can be reliably distinguished from for climatological studies. Similarly, the historical ocean subsurface temperature through plotting the indicators over sampling error (noise) with signal-to- high elevation areas of mountainous since 1940 for the upper 2000m through the map of Iran to ease displaying noise ratios larger than 3. several innovative steps. spatial tendency of the indicators and explaining the possible geographical

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 83 Section 4 role in controlling the spatial variation of interpolation. In this paper, the merits field. In order to produce a consistent the indicators. The results indicate that An Ensemble Average and of each reanalysis model are examined ensemble of realizations, the original ERA-Interim performs well in the majority Evaluation of the Third against the ensemble average for the 30- interpolation method used in E-OBS of the studied stations with strong Generation Global Climate year climate period 1981–2010. has been overhauled. In contrast to correlation coefficient. the kriging/spline method used in Reanalysis We find that the individual reanalysis earlier versions, we have made use However, it was found that the ERA- models perform similarly, but the Author Jeffrey Auger of Generalized Additive Modelling. Interim underestimates precipitation ensemble better approximates the Topographic effects are integrated in most of the stations located in the Affiliation University of Maine observed global average. The four- through the modelling of gridded coastal areas of the Caspian Sea as well Co-authors member reanalysis ensemble can be background fields that are calculated as in some stations along the Persian J. D. Auger (Climate Change Institute, examined through the website Climate using month-by-month climatological Gulf and the Oman Sea, suggesting that University of Maine), S. D. Birkel (Climate Reanalyzer (http://cci-reanalyzer.org). averages calculated over the period ERA-Interim is somewhat inefficient in Change Institute, University of Maine), K. 1961-90. accurately forecasting precipitation in A. Maasch (Climate Change Institute, the coastal areas; very likely due to not University of Maine), P. A. Mayewski An Ensemble Version of the Daily In addition to altitude, these background properly taking into account the complex (Climate Change Institute, University of E-OBS Dataset fields also incorporate additional topography of the region in its model Maine), K. C. Schuenemann (Metropolitan Author Richard Cornes environmental factors, such as coastal parameterization or not being able to State University of Denver) proximity and slope/aspect. To assess KNMI adequately differentiate between land Affiliation the success of the new interpolation and sea characteristics for the stations A global ensemble average of monthly Co-authors method, the gridded data are compared very close to the sea. It should be noted output from the four latest-generation Richard Cornes (KNMI), Gerard van der against several high-resolution gridded that the ERA-Interim is less efficient climate reanalysis models for the years Schrier (KNMI), Else van den Besselaar datasets produced by National in accurately forecasting extreme 1979–2013 is presented here. The models (KNMI), Phil Jones (CRU/UEA) Meteorological Services (NMS) across precipitation in the Caspian Sea region. used in this study are ECMWF Reanalysis Europe. Interim (ERA-I), NCEP Climate Forecast Daily, gridded datasets formed solely Nevertheless, we found very high System Reanalysis (CFSR), JMA 55-year from station data provide an important These datasets generally contain many agreement between observations and Reanalysis (JRA-55), and NASA Modern- tool for the evaluation of reanalysis more station data and are therefore ERA-Interim in this region when some Era Retrospective Analysis for Research datasets. However, uncertainty in the expected to replicate the true daily extreme precipitation events were and Applications (MERRA). Although each gridded datasets is rarely taken into fields of temperature or precipitation excluded from the analysis. Contrarily, of these models is considered state-of- consideration in such comparisons, more accurately than E-OBS, but do the results suggest an over-estimation the-art, an ensemble average can afford a primarily because few gridded datasets so at a scale that is comparable to for most of the stations located more statistically robust climate signal by provide estimates of uncertainty. In this E-OBS. On the whole the new version in northwestern and northeastern smoothing model biases. study we describe a new version of of E-OBS has reduced error relative to mountainous areas of the country; the daily, Europe-wide E-OBS gridded these NMS datasets compared to the once again due to perhaps improper Meteorological fields within the ensemble temperature and rainfall dataset that current operational version of the dataset representation of the topography of average include 2-meter air temperature, contains a number of significant (version 14.0). these regions in the numerical weather precipitation, and 500-hPa geopotential developments over earlier releases. The new version of E-OBS is expected to prediction model. heights. The original reanalyses were translated onto a common 0.5°x0.5° Notably, uncertainty estimates are aid evaluation of global-scale reanalyses latitude-longitude grid using bilinear generated from a 100-member ensemble across Europe, but particularly of realizations of each daily gridded European-scale regional reanalyses.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 84 Section 4

ERA-Interim precipitation is larger following the guidelines of the will be discussed through an analysis An Intercomparison between than observed precipitation in most of Atmospheric Model Intercomparison of variables representing the jetstream, ERA-Interim Reanalysis and Northeast China. Project (AMIP). storm tracks, and blocking. Theory suggests an enhanced equator-to-pole Observed Precipitation in In spring, autumn, and winter, the ERA- Observations and numerous reanalyses, temperature gradient will decrease Northeast China Interim precipitation value is close to the including the Modern Era Retrospective zonal flow in the Mid-latitudes, thereby observation one, while in summer there analysis for Research and Applications – Author Jie Zhou increasing meridional flow and slowing is a large difference in Liaoning Peninsula Version 2 (MERRA-2), have demonstrated the progression synoptic systems and Affiliation Chongqing Climate and Changbai Mountain between the two that the Arctic has warmed more rapidly it will be demonstrated that this is not Center, Chongqing kinds of precipitation data. In terms of than anywhere else in the world, referred necessarily the case in M2AMIP. Meteorological Service temporal characteristics, the time series to as “Arctic Amplification”, though Co-authors of the ERA-Interim precipitation matches uncertainty still remains regarding how Analysis increments from reanalyses as Jie Zhou(Chongqing Climate well with the observed precipitation in this has impacted the Mid-latitudes. well as a comparison to a free-running Center,Chongqing Meteorological whole. In different seasons, the annual version of the model both provide While MERRA-2 indicates that the Service),Junhu Zhao(Laboratory for variation of the ERA-Interim precipitation valuable, but unique, details that can be Arctic Amplification has occurred, a Climate Studies, National Climate Center, is well correlated with that of the used to understand the climate of and ten member ensemble of the MERRA-2 China Meteorological Administration) observed precipitation. biases within the model itself.” Atmospheric Model Intercomparison Recently, the European Center for Project (M2AMIP) simulations, using Medium-Range Weather Forecasts An Intercomparison of Changes the same prescribed climate forcing, Annual and semiannual cycles (ECMWF) released a new set of Associated With Earth’s Lower including Sea Surface Temperature of midlatitude near-surface reanalysis data-ERA-Interim. We make Tropospheric Temperature Using (SST) and ice, does not. An evaluation temperature and tropospheric of the temperature tendency within the an intercomparison between ERA-Interim Traditional and AMIP-style baroclinicity: reanalysis data and precipitation and observed precipitation lower troposphere due to radiation, in Northeast China. The results show Reanalyses moisture, and dynamics as well as the AOGCM simulations that, in general, the ERA-Interim Author Allison Collow surface energy budget in MERRA-2 and Author Valerio Lembo M2AMIP will demonstrate that despite reanalysis precipitation data can describe Universities Space University of Hamburg Affiliation identical prescribed SSTs and sea ice in Affiliation the spatial and temporal characteristics Research Association of seasonal precipitation in Northeast bothversions, enhanced warming in the Co-authors China well. Co-authors Arctic and a suppressed warming in the V Lembo (University of Hamburg) I Bordi A. B. Collow (USRA and NASA GSFC), Mid-latitudes in MERRA-2 is in response (CINFAI)A Speranza (CINFAI) In terms of spatial distribution, ERA- M. G. Bosilovich (NASA GSFC) to the analysis increment tendency due Seasonal variability in near-surface air Interim precipitation is generally to temperature observations that correct “Reanalyses have become an integral temperature and baroclinicity from the consistent with the observation data in for issues related to inconsistent SST and tool for evaluating regional and global ECMWF ERA-Interim (ERAI) reanalysis is different seasons in Northeast China. ice boundary conditions, as presented by climate variations, and even more about analysed in this study. This is compared There is a larger difference in the center Cullather et al. of Northeast China than in other areas the climate and the reanalysis itself with a set of six coupled atmosphere– between the two kinds of data. The can be learned through comparison Furthermore, the implications of the ocean general circulation models to identical free-running simulations weaker equator-to-pole temperature gradient in M2AMIP on the Mid-latitudes

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 85 Section 4

(AOGCMs) participating in the Coupled in both hemispheres with larger errors moisture observation data, so soil Soil Moisture Dataset (1981-2010) (V1.0)” Model Intercomparison Project phase 3 in the estimates, denoting increased moisture reanalysis datasets, which have provided by National Meteorological and 5 (CMIP3 and CMIP5). uncertainty and some disagreement advantages of global coverage, long Information Center, we compare and among models and with ERAI. We time series and spatial and temporal analyze four soil moisture reanalysis The annual and semiannual cycles believe that better constraining the cyclic continuity, are often used as alternative datasets: CFSR, ERA-Interim, NCEP R-1 of hemispherically averaged fields response of current global atmosphere– data in land-atmosphere interaction and NCEP R-2’s applicability in China. are investigated using univariate and ocean models to the external (solar) research. bivariate spectral analysis. The aim is The results show that: (1) In the aspect forcing might be helpful for the to assess the agreement between ERAI Because each reanalysis datasets use of spatial distribution, four reanalysis improvement of seasonal forecasts. and coupled models in the reproduction different numerical prediction models datasets can basically describe the of the near-surface temperature and and assimilation methods, there are spatial distribution of soil moisture in baroclinicity annual and semiannual Applicability Analysis of Four some data quality differences, especially China, but NCEP R-1 reanalysis dataset cycles and their coherency and relative Soil Moisture Reanalysis quality inconsistency of various soil has problem in western Tibetan Plateau phase. Concerning univariate analysis, a Datasets in China moisture reanalysis datasets, so it is soil moisture simulation; (2) In the aspect statistically significant power spectrum essential to evaluate applicability of of time variation, CFSR can well describe peak is found at the annual frequency Author Zhi Zhu various soil moisture reanalysis datasets time series of soil moisture, and NCEP in the zonally averaged fields of both Affiliation National Meteorological in China, which can provide beneficial R-2 has the worst performance over four hemispheres. Information Center reference to climate and drought reanalysis datasets; (3) In the aspect research. of seasonal cycle of soil moisture, in The semiannual peak, instead, shows Co-authors surface layer, CFSR and ERA-Interim less power and in the NH seems to Zhi Zhi(National Meteorological The historical soil moisture observation are better, and NCEP R-1, NCEP R-2 have a more regional character, being Information Center),Chunxiang Shi data of China mainly originate from overestimate soil moisture in simulation; observed in the North Pacific Ocean (National Meteorological Information agricultural meteorological observation In deep layer, except for NCEP R-1, region. Bivariate analysis for such Center) stations built by China Meteorological other three reanalysis datasets can a region and the whole Southern Administration, and these data are mainly basically simulate the seasonal cycle of Hemisphere midlatitudes shows some The exchange process of water, kept in paper form, which have not been soil moisture; (4) All of four reanalysis discrepancies between ERAI and heat and momentum between land used wildly and effectively. In 2014, datasets have their problems, which still model data, as well as among models, surface and atmosphere is called land National Meteorological Information need further improvements. Key words: especially regarding the semiannual surface process. Soil moisture is an Center finished digitization and quality Soil Moisture; Reanalysis Datasets; frequency. Specifically, (i) models and important physical parameter in land control work of historical soil moisture Spatial Distribution; Time Variation ERAI agree on the coherency at the surface process research, and also an observation data, and developed the annual and semiannual frequency in important index to verify the accuracy “China Agricultural Meteorology Soil both hemispheres, and (ii) on the annual of hydrological process in land surface Moisture Dataset (1981-2010) (V1.0)”, frequency, showing a relative phase of process simulation, which receives which provides a newer and more 220±15°. extensive attention from researchers in reliable soil moisture observation data different fields. for soil moisture reanalysis datasets The latter denotes an approximately assessment. 1-month phase shift between Although soil moisture is very important temperatures and baroclinicity annual to climate and drought research, Using soil moisture observing data of cycle. At the semiannual frequency relevant researches are hindered by 150 agricultural meteorology stations model phases show a wider dispersion temporal and spatial limitation of soil from “China Agricultural Meteorology

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 86 Section 4

So, different reanalysis data namely Step wise linear regression also indicates winds in the vicinity of southern Appraise the performance of ERA-interim, NCEP/NCAR and MERRA that two meter air temperature and Geo Greenland. Comparisons are made to different reanalysis over Western were considered to check the proximity potential height as the most reliable observations from surface and upper- Himalayan Region with observed data so that in future those predictors over the study area. air stations, as well as from research data can be used reliably for any kind of aircraft flights during the Greenland Flow Author Monami Dutta further analysis and for this two meter Distortion Experiment (GFDex). Affiliation Bidhan Chandra Krishi air temperature is used as a parameter. Arctic System Reanalysis The ERA-I reanalysis has a tendency to Viswavidyalaya Monthly correlation map analysis improvements in underestimate high wind speeds and suggested that ERA-interim is superior topographically-forced winds Co-authors overestimate low wind speeds, which is to NCEP/NCAR and MERRA in almost all Monami Dutta (Bidhan Chandra Krishi near Greenland reduced in ASRv1 and nearly eliminated the months and for most of the station Viswasvidyalaya), Lalu Das (Bidhan in ASRv2. In addition, there is generally locations. Author Kent Moore Chandra Krishi Viswasvidyalaya) a systematic reduction in the root-mean- Affiliation University of Toronto Principal Component Analysis (PCA) square error between the observed Reanalysis data are the state-of-the-art also indicated that ERA-interim is closer Co-authors and the reanalysis wind speeds from archive of past meteorological variables to observation however for few station G.W.K. Moore (University of Toronto), D. ERA-I to ASRv1 to ASRv2, the exception spanning the entire atmosphere. ERA- locations NCEP/NCAR is predominating. Bromwich (Ohio State University), A. being low-level marine winds where interim which is often considered as an Some statistical analysis like RMSE, Wilson (Ohio State University), I. Renfrew the correspondence is similar in both observed data is used in the present NSE and d-index between observation (University of East Anglia), L. Bai (Ohio reanalyses. Case studies reveal that study to evaluate its performance with and three reanalysis data mentioned State University) mesoscale spatial features of the wind the observational station data over above also indicate that for two meter air field are better captured in ASRv2 as Western Himalayan. In addition this Southern Greenland is home to a number temperature, ERA-interim can be reliably compared to the ERA-I or ASRv1. These data is also used as a predictor for the of weather systems characterized by high used as a substitute of observed data results confirm that a horizontal grid purpose of downscaling and future speed low level winds that are the result followed by NCEP/NCAR reanalysis. size on the order of 15 km is needed to projection over the same study area. of topographic flow distortion. These Second part of study involves analysis characterize the impact that Greenland’s Sixteen observed station location was systems include tip jets, barrier winds the skill of different predictors from topography has on the regional wind considered which is irregularly distributed and katabatic flows. Global atmospheric ERA-interim and NCEP/NCAR for the two field and climate. However even at this over three states of northern India. reanalyses have proven to be important meter air temperature. tools in furthering our understanding of resolution, there are still features of the Like all the other tropical mountains of wind field are under-resolved. Two meter air temperature and moisture these weather systems and their role in the world, Himalaya, also responds at flux from ERA-interim and geo potential the climate system. However, there is a faster rate to climate changes with height from NECP/NCAR is selected as evidence that their mesoscale structure increase in temperature of 0.84OC for most reliable predictor over the study may be poorly resolved in these global period 1969-2009. In Western Himalaya area through the Canonical Correlation products. remote locations do not have observed Analysis (CCA) between the Principal data however, few high altitude stations Here output from the regional Arctic Component Analysis (PCA) of station have meteorological records but quality System Reanalysis (ASRv1–30 km and data and Empirical Orthogonal Function and quantity are questionable. ASRv2–15 km grid resolutions) are (EOF) of predictor field. compared to the global ERA-Interim Reanalysis (ERA-I–80 km grid resolution), focusing on their ability to represent

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 87 Section 4

In this study, we focus on the Southeast Southeast Pacific over a time period is limited by surface moisture availability Assessment of cloud geometry Pacific which hosts the largest of 16 years between 2001 and 2016. and hence sensitive to local precipitation, in ERA-Interim and ERA-20C subtropical stratocumulus deck on Earth. Furthermore, regional and seasonal the MERRA-2 LH biases are reduced over the Southeast Pacific using The associated stratocumulus clouds variabilities of cloud heights are from those in MERRA, and the direction satellite observations represent a critical but poorly understood investigated. of change is consistent with the component of the coupled climate precipitation increments from inserting Author Christoph Böhm system of the region that is characterized the observed precipitation. However, Assessment of MERRA-2 Land Affiliation University of Cologne by strong coastal upwelling and one of large positive biases remain in some the driest regions on Earth land inwards, Surface Energy Flux Estimates regions where LH is not moisture-limited. Co-authors i.e. the Atacama desert. Christoph Böhm (Institute of Geophysics Author Rolf Reichle The globally averaged anomaly and Meteorology, University of Cologne, Within the German Science Foundation Affiliation NASA/GSFC correlations (Ranom) with reference data Germany), Susanne Crewell (Institute of funded Collaborative Research Center Co-authors were improved from MERRA toMERRA-2, Geophysics and Meteorology, University “Earth at its dry limit” our overarching C. S. Draper (NASA/GSFC and NOAA for both LH (from 0.40 to 0.50 vs. of Cologne, Germany), Ulrich Löhnert goal is to understand the moisture supply ESRL/CIRES), R. H. Reichle (NASA/ GLEAM data) and the daily maximum (Institute of Geophysics and Meteorology, to the Atacama desert and its variability GSFC), and R. D. Koster (NASA/GSFC) T2m in Boreal summer (from 0.64 to University of Cologne, Germany), which is to a large degree affected by 0.70, vs. CRU data). There is a strong Johannes Quaas (Institute for stratocumulus clouds moving inland. In NASA’s Modern-Era Retrospective correspondence between regions of the Meteorology, University of Leipzig, Reanalyses such as ERA-Interim and analysis for Research and Applications, greatest improvement in the MERRA-2 Germany), Odran Sourdeval (Institute for ERA-20C are well suited to study trends version 2 (MERRA-2) reanalysis the T2m Ranom, and regions where the Meteorology, University of Leipzig, and variability in cloud geometry with land is forced by replacing the model- MERRA-2 T2m is most sensitive to Germany), Johannes Mülmenstädt respect to interannual and interdecadal generated precipitation with observed the inserted observed precipitation, (Institute for Meteorology, University of patterns such as El Niño Southern precipitation before it reaches the suggesting that the observed precipitation Leipzig, Germany) Oscillation or Pacific Decadal Oscillation. surface. We assess the MERRA-2land did in fact lead to improved T2m. surface energy fluxes and 2 m air In order to further assess the quality The representation of clouds in temperatures (T2m) and investigate of the reanalyses, a comparison to climate models is still subject to large whether the inserted precipitation satellite retrievals from Multi-angle uncertainties. In particular this holds observations result in the expected Imaging SpectroRadiometer (MISR) true for marine boundary layer clouds. improvements to these fields. Averaged on Terra is carried out. In addition, As the Earth’s radiation budget is over global land, MERRA-2 overestimates to the more traditional parameters strongly influenced by clouds, these the latent heat (LH) and incoming cloud fraction and cloud top height a uncertainties introduce a wide spread shortwave radiation (by 5-10 W/m2) novel approach enables us to derive among simulations of future temperature and underestimates (in magnitude) CBHs with a horizontal resolution of increase. Important parameters which the incoming and outgoing longwave 0.25°x0.25°. Previous research shows a affect the net radiative effect of clouds radiation (by 10-15 W/m2), while the good agreement of these observations are cloud cover along with cloud top and sensible heat biases are unclear. cloud base height (CBH). with ceilometer measurements within a continental region of the USA. Here, The global average biases differ only this new approach is applied to an area slightly from those in NASA’s previous within the stratocumulus region of the reanalysis, MERRA. In regions where LH

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 88 Section 4

and numerical high-resolution CORDEX circulation and the main differences are Assessment of reanalysis simulations in reproducing precipitation Assessment of summer seen in surface temperature anomalies, precipitation extremes over Italy extreme events over Italy. monsoon features derived from especially by CFSR pattern. from global reanalysis products, In particular, the Med-CORDEX three reanalysis datasets over Further, we show that the mechanisms high-resolution simulations and simulations driven by ERA-Interim will Southern Hemisphere linked to regional monsoon trigger be taken into account. The observation increase/reduction of the precipitation historical observations Author Vanucia Schumacher series was retrieved from the national over different areas in the Southern Author Emanuela Piervitali system of climate data SCIA and covers Affiliation University of Viçosa Hemisphere. The monsoon patterns Affiliation Istituto Superiore per la almost uniformly the country. The Co-authors related by reanalyses are very similar, Protezione e la Ricerca series were selected in order to meet V. Schumacher (Federal University but they differ in terms of its magnitude Ambientale (ISPRA) severe completeness and continuity of Viçosa), F. Justino (Federal University and variability, in which JRA-55 is more Co-authors requirements. Potentially inhomogeneous of Vicosa), A. Silva (Federal University of similar to the ERA-interim than to CFSR G Fioravanti (ISPRA), A Dell’Aquila records at yearly level were discarded. Vicosa), N. Leonardo(Federal University patterns. (ENEA), S Calmanti (ENEA), F Desiato First, a number of contiguous subregions of Vicosa), A. Comin (FederalUniversity (ISPRA), E Piervitali (ISPRA) were identified using hierarchical cluster of Vicosa) analysis based on daily observations of Assessment of ten ocean Reanalysis gridded datasets are a precipitations. The present study focuses on ability of reanalyses in the polar regions valuable source of information for the three reanalyses, namely: Interim Author Dorotea Iovino monitoring climate variability and Then the spatial and temporal ECMWF Reanalysis (ERA-Interim), change and assessing the evolution occurrence of moderate extreme rainfall Japanese 55-year Reanalysis (JRA- Affiliation CMCC of climate extremes, which can have events in each cluster was investigated 55) and the Climate Forecast System Co-authors severe impacts on the society and the through the calculation of a subset of Reanalysis (CFSR) to explore the Doroteaciro Iovino (Centro Euro- environment. Nonetheless, systematic indices from the Expert Team on Climate main characteristics associated with Mediterraneo sui Cambiamenti Climatici, biases and uncertainties can affect the Change Detection and Indices (ETCCDI). regional summer monsoon in Southern Italy), Petteri Uotila (Finnish ability of reanalysis system in describing Summary statistics from the observed Hemisphere, based on circulation indices Meteorological Institute), Marika Marnela the true state of climate, specially at the records and the gridpoint series from from 1981-2010 period. (Finnish Meteorological Institute), Meri low-resolution reanalysis products and local scale. Results show that the three reanalyses Korhonen (Finnish Meteorological corresponding high-resolution dynamical Institute), Antoine Barthélemy (Université The Italian Peninsula with its complex datasets can reproduce the spatial downscaling were compared over the catholique de Louvain), Hugues Goosse topography can be regarded as an variability of the zonal wind more reliable period from 1979 to the last decade. (Université catholique de Louvain), interesting test for assessing reanalysis as compared to precipitation in each François Massonnet (Université representation of climatic extremes. We monsoon domain: southern Africa, South catholique de Louvain, Belgium and took advantage of the availability of a America and Australia. The ERA-interim Barcelona Supercomputing Centre, new dataset of high-quality, land-based and JRA-55 have better skills than CFSR Spain), James Carton (University of precipitation records of observations to in all monsoon domains. Based on three Maryland), Keith Haines (University of compare and evaluate the capability of reanalyses datasets the large scale Reading, UK), Davi Mignac Carneiro low-resolution global reanalysis products monsoonal patterns show that common features among tropical monsoons (University of Reading, UK), Frank Kauker are characterized by low-level cyclonic (Alfred Wegener Institute, Germany), Matthieu Chevallier (Centre National de

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 89 Section 4

Recherches Météorologiques, Météo polar physics, such as sea ice, have been and between the mixed layer depth, lossof accuracy in regions where the France/CNRS UMR3589, France), Marie updated where necessary and collected oceanic convection, the upper ocean conventional observation network is Drevillon (Mercator Ocean, France), Gilles in a public database. hydrography and sea ice. weak such as the Southern Hemisphere Garric (Mercator Ocean, France), and above the tropopause. In addition to model output, available We will also present other diagnostic Clement Bricaud (Mercator Ocean, observational polar climatologies are results which provide closely related This initial assessment focuses on the France), Neven Fuc˘kar (Barcelona collected and used in the assessments. information for those interested in monthly up to the decadal variability for a Supercomputing Centre, Spain), Vidar Due to the extensive variety of products, enhancing model predictive skill over a set of surface and tropospheric variables. Lien (Institute of Marine Research, this database should become a range of time scales, including seasonal The results are compared with other Norway), Jiping Xie (Nansen valuable resource outside the PORA- to decadal. available reanalyses (R1, CFSR, JRA55c, Environmental and Remote Sensing IP community. For a comprehensive ERAI and MERRA2). Center, Norway), K Andrew Peterson (Met evaluation of the ten ORA products Office, UK), Steffen Tietsche (the (CGLORSv5, ECDA3.1, GECCO , Assessment of the Conventional European Centre for Medium-Range 2 Glorys2v4, GloSea5_GO , MOVEG2i, Observation Reanalysis (CORe) Benchmarking Northern Weather Forecasts), Li Shi (the Bureau of 5 ORAP5, SODA3.3.1, TOPAZ4 and Hemisphere midlatitude Meteorology, Australia), Zhaoru Zhang Author Li Zhang UR025.4) in the Arctic and Southern atmospheric synoptic variability (Shanghai Jiao Tong University), Remon INNOVIM/CPC/NOAA Oceans several specific diagnostics are Affiliation Sadikhi (University of Hamburg) in centennial reanalysis and assessed. Co-authors numerical simulations Li Zhang (Innovim), Arun Kumar (CPC/ Ocean reanalysis (ORA) combines The PORA-IP diagnostics target the NCEP/NOAA), Jeffrey Whitaker (PSD/ Alessandro Dell’Aquila observations either statistically or with Author following topics: hydrography; heat, NOAA), Jack Woollen (IMSG), Wesley a hydrodynamical model, to reconstruct Affiliation ENEA salinity and freshwater content; ocean Ebisuzaki (CPC/NCEP/NOAA), Hyun-Chul historical changes in the ocean. Co-authors transports and surface currents; mixed Lee (EMC/NOAA) Global and regional ORA products are layer depth; sea-ice concentration and Alessandro Dell’Aquila (ENEA), Susanna increasingly used in polar research, but thickness; and snow thickness over sea The Conventional Observation data Corti (ISAC-CNR) , Antje Weisheimer their quality remains to be systematically ice. Based on these diagnostics, ORA based EnKF (Ensemble Kalman Filter) (ECMWF, Uni. Oxford) , Hans Hersbach assessed. To address this, the Polar ORA product biases against observed data atmospheric reanalysis (CORe) was (ECMWF), Carol Peubey (ECMWF), Intercomparison Project (PORA-IP) has and their mutual spread are quantified, recently completed at the National Paul Poli (ECMWF, MeteoFrance), Paul been established following on from the and possible reasons for discrepancies Centers for Environmental Prediction Berrisford (ECMWF) , Dick Dee (ECMWF), ORA-IP project (Balmaseda et al. 2015, discussed. (NCEP), for the period of 1950 to 2010. Adrian Simmons (ECMWF) with other papers in a special issue of The observations assimilated include So far, we have identified product outliers The representation of midlatitude winter Climate Dynamics). surface station data, radiosondes and and evaluated the multi-model mean. atmospheric synoptic variability in pibals, profilers, aircraft data, and satellite The PORA-IP is constituted under the We have identified the importance of the centennial reanalysis products, which winds. The EnKF system is based on the COST EOS initiative with plans to review atmospheric forcing, air-ocean coupling assimilate surface observations only, latest Semi-Lagrangian Global Forecast reanalyses products in both the Arctic protocol and sea-ice data assimilation and atmospheric model simulations System (GFS) T254 L64 model. and Antarctic, and is endorsed by YOPP for the product performance. Moreover, constrained by observation-based – the Year of Polar Prediction project. we are investigating co-variability By not assimilating satellite radiances, datasets is assessed. Midlatitude waves Currently, the PORA-IP team consists between the Arctic Ocean heat content CORe avoids the spurious climate activity in twentieth century reanalyses of 23 researchers from 16 institutes and and the North Atlantic heat transport, shifts caused by introduction of new (20CR, ERA-20C) and atmospheric universities. The ORA-IP products with satellites. However, one expects a larger model simulations (AMIP ERA-CLIM) are

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 90 Section 4 compared with those estimated from possible model bias, lack of observations There are, however, many spurious observationally-complete reanalysis Biases in the 20th Century in this region at this time, and nonlinear changes and discontinuities in the products. Reanalysis Version 2c interactions with the data assimilation raw radiosonde records resulting from system. Many of these issues are being changes in instruments, observational All reanalyses are in good agreement Author Laura Slivinski addressed in the new 20CR version 3 practice, processing procedures, station regarding the representation of the Affiliation Univ. of Colorado’s system currently in development. relocations, and other issues. Recently, synoptic variability during the last Cooperative Institute for the daily humidity records radiosonde decades of the twentieth century. This Research in derived from about 130 Chinese stations suggests that the assimilation of surface Environmental Sciences Changes of atmospheric were homogenized using a new approach observations can generate high-quality Co-authors precipitable water in developed by Dai et al. (2011). extratropical upper-air fields. In the observations and reanalysis over first decades of the twentieth century LC Slivinski (CIRES/NOAA), GP Compo It is shown that the homogenization a suppression of high frequency (CIRES/NOAA), JS Whitaker (NOAA), China removes the large shifts in the original PD Sardeshmukh (CIRES/NOAA) variability is apparent in the centennial Author Tianbao Zhao records of humidity resulting from sonde reanalysis products. changes in recent years in China, and it The NOAA-CIRES Twentieth Century Affiliation Institute of Atmospheric improves correlation of the precipitable This behaviour does not have a Reanalysis version 2c (20CRv2c) was Physics (IAP), Chinese water (PW) with precipitation and the counterpart in the atmospheric model publicly released in 2015, and included Academy of Sciences spatial coherence of the PW trend during integrations. Since the latter differ from many improvements over the previous (CAS) recent 40 years. The PW variations one of the reanalysis products considered version 2 system. However, several Co-authors and changes are highly correlated with here (ERA-20C) only in the assimilation of biases and issues in version 2c remain. Jingpeng Zhang (Key Laboratory of those in lower–midtropospheric mean surface observations, it seems reasonable First, version 2c used a digital filter in Regional Climate-Environment Research temperature (r = 0.83), with a dPW/dT to attribute the high frequency variability its 6 hour first guess fields to damp for East Asia, Institute of Atmospheric slope of ~7.6% K−1, which is slightly suppression to the poor coverage of the gravity waves that can cause numerical Physics, Chinese Academy of Sciences, higher than the 7% K−1 implied by observations assimilated. instabilities. This filter generated artificial China), Tianbao Zhao (Key Laboratory of trends in precipitation that can be seen Clausius–Clapeyron equation with a Regional Climate-Environment Research constant relative humidity (RH). in the forecast fields: the hour 3-6 for East Asia, Institute of Atmospheric precipitation forecasts are consistently Physics, Chinese Academy of Sciences, The radiosonde data show only and significantly larger than the hour China) small variations and weak trends in 0-3 forecasts. Second, version 2c did tropospheric RH over China. Using these not include bias correction to marine Radiosonde humidity data provide the homogenized observations, the PW from observations. longest record for assessing changes in the NCEP/NCAR, NCEP/DOE, MERRA, atmospheric water vapor, but they often In the 19th century, these observations JRA-55, JRA-25, ERA-Interim, ERA-40, contain large discontinuities because were strongly biased, and have been CFSR and 20CR reanalyses is evaluated of changes in instrumentation and shown to significantly impact the global for the period from 1979-2012 (1970-2001 observational practices. sea level pressure in this time period. for ERA-40). Finally, 20CRv2c has an apparent high- In this study, the variations and trends Results suggest that the PW biases in pressure bias over the high Southern in tropospheric humidity (up to 300 the reanalyses are within ~20% for most latitudes in the early-to-mid 20th century. hPa) over China are analyzed using a of northern and eastern China, but the Potential reasons for this include a newly homogenized radiosonde dataset.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 91 Section 4 reanalyses underestimate the observed during the southwest monsoon season PW by 20%–40% over western China, Characterization of Air-Sea (JJAS) in the Bay of Bengal. Results CHOCO-JEX: A Research and by ~60% over the southwestern Fluxes from Reanalysis Products show that TropFlux and (to a slightly Programme Focused on the Tibetan Plateau. The newer-generation over the Bay of Bengal during lesser extent) ERA-I perform best, with CHOCO Low-level Jet over the reanalyses (e.g., JRA25, JRA55, CFSR the Southwest Monsoon the highest correlations and smallest Far Eastern Pacific and Western and ERA-Interim) have smaller root- biases when compared to the observed mean-square error (RMSE) than the Author Alejandra Sanchez-Franks meteorological parameters and the Colombia – Reanalysis older-generation ones (NCEP/NCAR Affiliation National Oceanography associated fluxes from the RAMA array. Evaluation NCEP/DOE and ERA-40). Most of the Centre In contrast, MERRA2, CFSR and JRA-55 Author Johanna Yepes reanalyses reproduce well the observed Co-authors have lower correlations and much higher Affiliation Universidad Nacional de PW climatology and interannual A. Sanchez-Franks (1National biases when compared to the observed Colombia variations over China. Oceanography Centre, Southampton, data. In general, however, all products Co-authors However, few reanalyses capture the UK), E. C. Kent (1National Oceanography struggle to capture shortwave radiation Johanna Yepes (Departamento de observed long-term PW changes, Centre, Southampton, UK), A. J. flux (SWR) and latent heat flux (LHF), with Geociencias y Medio Ambiente, primarily because they show spurious Matthews (Centre for Ocean and non-negligible biases ranging from -6 W/ Universidad Nacional de Colombia, Sede wet biases before about 2002. This Atmospheric Sciences, School of m2 to 75 W/m2. Further analysis of the Medellín, Facultad de Minas, Medellín, deficiency results mainly from the Environmental Sciences and School of flux variables showed SWR and LHF to Colombia), Germán Poveda discontinuities contained in reanalysis Mathematics, University of East Anglia, be the largest drivers of the observed (Departamento de Geociencias y Medio RH fields in the mid-lower troposphere Norwich, UK), B. G. M. Webber (Centre net heat flux variability, thus highlighting Ambiente, Universidad Nacional de due to the wet bias in older radiosonde for Ocean and Atmospheric Sciences, the importance of the results from the Colombia, Sede Medellín, Facultad de records that are assimilated into the School of Environmental Sciences and reanalysis product comparison to the Minas, Medellín, Colombia), John F. Mejía reanalyses. Thus, more efforts are School of Mathematics, University of East RAMA buoy. (Desert Research Institute, Reno, NV, needed to remove spurious changes Anglia, Norwich, UK), S. C. Peatman It was also found that mean fields were United States), Leswis Cabeza (Centro de in input data for future long-term (National Centre for Atmospheric Science, consistent with the findings at the buoy Investigaciones Oceanográficas e reanlayses. Climate and Department of Meteorology, location, indicating confidence in the Hidrográficas del Pacífico, Tumaco, University of Reading, UK), P. N. representation of variability across the Colombia), Carolina Rueda (Subdirección Vinayachandran (Centre for Atmospheric basin. Finally, the representation of the de Meteorología, Fuerza Aérea and Oceanic Sciences, Indian Institute of intraseasonal variability was investigated Colombiana, Bogotá, Colombia) Science, Bangalore, India). through the boreal summer intraseasonal The Choco Low-Level Jet (Choco Jet) oscillation and it was shown that Meteorological variables and surface flux has been related to the formation of large TropFlux and ERA-I perform best at variables from five reanalysis products and frequent Mesoscale Convective capturing intraseasonal climate variability are compared and evaluated against in- Systems over the far eastern Pacific during the southwest monsoon season. situ data from the RAMA moored array. Ocean and inland over the world-record The reanalysis products, ERA-Interim rainy region of western Colombia. The (ERA-I), TropFlux, MERRA2, JRA-55 structure and dynamic of the Choco and CFSR are specifically assessed for Jet have been studied using reanalysis their characterisation of air-sea fluxes products, but no permanent upper-air

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 92 Section 4 soundings have been put in place on of the CHOCO-JEX IOPs was carried While in the winter and summer seasons the region neither for improving the out in the city of Quibdó (5°41′32″N, Comparative evaluation of the these distinctions have a significant understanding of the Choco Jet nor 76°39′29″W) during June and October changes of the temperature in difference both in magnitude and sign. for evaluating the reanalysis skills to 2016. Results and data sets gathered the troposphere and There is also a non-linear character of capture and display regional and local during the four IOPs allowed us to stratosphere of the Northern the investigated period differences in air atmospheric circulations. contrast diverse reanalysis products temperature. This particularly evident such as Era-Interim, MERRA-2, NCEP/ Hemisphere according to in the Middle troposphere, where at the The CHOCO-JEX experiment is an NCAR and CFSR. Preliminary results reanalyses NCEP and ERA- beginning of the period the difference on-going international and inter- show striking cold and wet mid- Interim grows to a value of 0.8°C. Further, since institutional research program developed troposphere biases in the reanalysis over the second half of the 1980s and until by Universidad Nacional de Colombia Author Vladimir Guryanov both ocean and land. the beginning of the 21 century, the at Medellín, the General Maritime Affiliation Kazan Federal University difference goes to zero, and then grows Directorate of the Colombian Navy, the This effect is likely related with colder Co-authors again. Colombian Air Force, and the Desert radiative effect of smoothed terrain V.V. Guryanov (Kazan Federal Research Institute at Reno, Nevada, US. constrained to the reanalysis resolution At the end of the period the temperature University);K.M. Shantalinskiy (Kazan and dispersion of these errors over the difference, submitted by reanalyses R1 The main objective of CHOCO-JEX is Federal University);Yu.P. Perevedentsev regional ocean by the predominant mid- and R3, reaching values of 0.4°C. Non- to expand our understanding of the (Kazan Federal University) tropospheric easterly flow. However, linear course of temperature difference tropospheric flow characteristics of some noisier but warmer and drier is also reflected in the respective the Choco Jet through observations, According to the three reanalyses NCEP- biases are observed during organized coefficients of linear temperature trends. assimilation and reanalysis. To that end, NCAR1, NCEP-DOE2 and ERA-Interim convective activity episodes. Such In the same time sign of linear trend four 8-day Intensive Observation Periods (next, respectively, R1, R2 and R3) disturbed convective environments coefficient does not change. In General, (IPO) have taken place, two over land evaluated differences in air temperature appear to be unresolved by all reanalysis in the troposphere according to all and two over the Pacific off the coast in the free atmosphere averaged on products, even by those assimilating reanalyses holds temperature rise. Unlike of Colombia, including the deployment the Northern Hemisphere. The nature satellite data. Although there are not the troposphere, in the tropopause region of upper-air soundings to monitor the of the impact of these differences significant differences regarding the and lower stratosphere temperature trend predominant diurnal cycles patterns on the assessment of changes of air different reanalysis, NCEP/NCAR (the reversal is observed. (4 times per day) and the seasonal temperature during the period 1979- coarser reanalysis) shows the largest variability. The maritime IOPs took place 2013 is defined. Found that reanalysis According to the R1 and R2 on the biases, overestimating temperature during January and November 2016 on R2 and R3 are more equal temperatures surfaces of 200 and 100 hPa temperature around 5°C at mid-to-upper levels. board of the ARC Gorgona vessel. compared to R1. decreases, but according to R3 temperature changes are not statistically Such campaigns were constrained by The studies were identified differences in significant. In the middle stratosphere (30 the availability of the research vessel, dependence of reanalysis from the ocean and 10 hPa) according to all reanalyses whose schedule was tied to the near and land. In the lower troposphere over temperature decreases. yearly reconnaissance marine campaigns the oceans R3 gives lower values of air aiming to monitoring El Niño/Southern temperature compared to R2 and more The calculation of the coefficients of the Oscillation (ENSO) over the Colombian so with R1 (average for the year to 1.2°C). linear correlation between the time series coastal waters making part of the Estudio Over land temperature difference is not of temperature according to the R1, R2 Regional del Fenómeno de El Niño significant. and R3 showed that in the troposphere, (ERFEN). The continental component

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 93 Section 4 the correlation is great (more than 0.9). events as knowledge on the variability the atmospheric circulation as the main In the stratosphere the temperature time on different time-scales is of high Comparison of ten global predictor, with additional predictors series relationship R1 and R2 with R3 importance due to their damage-related reanalysis datasets for based on moisture, air temperature, and considerably less, especially over the impact. precipitation prediction with a vertical velocity. Many different reanalysis oceans. So, on the 100 hPa in January products are available nowadays that To achieve this, cyclone and windstorm statistical downscaling method over the oceans the correlation is close differ in terms of assimilation technique, time series are low-pass filtered with to zero. Author Pascal Horton assimilated data, atmospheric model, a cut-off frequency of 1/31 years and archive length, and spatial and temporal high frequency variability is assessed Affiliation University of Bern resolution. Comparison of Extra-tropical by calculating the remainder between Co-authors Cyclones and Windstorms in original and low-pass filtered time Pascal Horton (Oeschger Centre for The context of the application of ERA-20C and NOAA-20CR series. The results suggest partly large Climate Change Research, Institute of analogue methods might drive the choice differences w.r.t. long-term trends of both Geography, University of Bern, Bern, of an appropriate dataset, for example Reanalyses extra-tropical cyclones and windstorms, Switzerland), Rolf Weingartner (Oeschger when the archive length is a leading Author Daniel Befort most pronounced during the early 20th Centre for Climate Change Research, criterion. However, in many studies, a century. Interestingly, a better agreement Institute of Geography, University of reanalysis dataset is subjectively chosen, Affiliation University of Birmingham is found for high-frequency variability, Bern, Bern, Switzerland), Stefan according to the user’s preferences or Co-authors especially over the Northern Hemisphere. Brönnimann (Oeschger Centre for the ease of access. The impact of this D.J. Befort (University of Birmingham, The outcome of this study suggests that Climate Change Research, Institute of choice on the results of the downscaling School of Geography, Earth and it is difficult to draw reliable information Geography, University of Bern, Bern, procedure is rarely considered and no Environmental Sciences, Birmingham, about long-term variability of extra- Switzerland), Charles Obled (Laboratoire comprehensive comparison has been United Kingdom), S. Wild (University of tropical cyclone and windstorm events d’étude des Transferts en Hydrologie et undertaken so far. In order to assess Birmingham, School of Geography, Earth during the past century from these two Environnement, LTHE, Université de the impact of the archive’s quality in the and Environmental Sciences, reanalysis datasets. In contrast, studies Grenoble-Alpes, Grenoble, France) analogue method, ten global reanalysis Birmingham, United Kingdom), T. focusing on short-term variability of these datasets were compared in seven Kruschke (GEOMAR Helmholtz Centre for events might be useful if long-term trends The analogue method allows predicting versions of the analogue method, over Ocean Research Kiel, Germany), U. are taken into account. precipitation by means of a statistical 300 precipitation stations in Switzerland. Ulbrich (Institute of Meteorology,Freie downscaling of synoptic predictors. To Universität Berlin, Germany), G.C. predict the precipitation for a target day Despite the fact that all reanalysis Leckebusch (University of Birmingham, of interest, analogue days are sought datasets might be considered accurate School of Geography, Earth and in long archives of synoptic predictors, for central Europe, differences in terms of Environmental Sciences, Birmingham, typically from reanalysis datasets. prediction performance were identified. United Kingdom) Satellite-based products generally A certain number of analogue days are showed higher skills. There were no Extra-tropical cyclones and windstorms then extracted and their corresponding overall winner amongst these, but over both hemispheres are analysed observed precipitation is used to some datasets were found to perform for the 20th century in two reanalysis establish a conditional empirical better for different methods. MERRA-2 datasets, ERA-20C and NOAA-20CR (v2) distribution, which is the statistical provides SLP data particularly skillful (Befort et al., 2016). Analyses focus on prediction for the target day. Most of in the analogue method. Geopotential long and short-term variability of these the recent analogue methods rely on heights from CFSR show slightly higher

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 94 Section 4 skills, as well as the vertical velocity Their data assimilation systems approach is that uncertainty is generated from JRA-55. Increasing the complexity range from nudging of conventional COSMO ensemble reanalysis throughout the model simulation. of the analogue method was relevant observations (DWD), optimal interpolation system for Europe: diagnostics Therefore, the system can be utilized only for certain datasets, while it led to for surface observations (MeteoFrance), of quality of data assimilation with a deterministic forcing at the lateral a decrease of performance for others. 3D-Var for the full observing system and uncertainty estimates boundaries. This work can thus help choosing an (SMHI) to 4D-Var for UKMO. Here Here, the system is used for the appropriate dataset for the analogue we investigate how the results differ, Author Maarit Lockhoff production of a 21 member ensemble method considered, or raise awareness with special focus on wind fields. The Affiliation University of Bonn for an initial 5 year time period. In this of the consequences of using a certain 10m-windspeed and also wind speed Co-authors presentation, we focus on the evaluation dataset. for several model heights up to 100m M. Lockhoff (University of Bonn), of the quality of the data set using basic are compared with station and mast M. Borsche (Deutscher Wetterdienst), diagnostics for observations and data observations. ERA-Interim is added in the L. Bach (Deutscher Wetterdienst), assimilation monitoring as well as on the Comparison of wind fields from comparison as a benchmark. European regional reanalyses C. Schraff (Deutscher Wetterdienst), probabilistic evaluation using standard from the UERRA project and Mean square error, bias, correlation K. Stephan (Deutscher Wetterdienst), measures for ensemble reliability and/or and other skill scores are investigated J. Keller (Deutscher Wetterdienst) resolution, e.g. spread-skill relation, rank COSMO-REA6 to quantify the differences in the four histograms, Brier/CRPS scores. reanalyses depending on local and The objective of the FP-7 funded Author Deborah Niermann The provided uncertainties are also temporal scale. In general, the synoptic project Uncertainties in Ensembles of Affiliation Deutscher Wetterdienst evaluated by comparison against other patterns are captured well by all regional Regional Reanalyses (UERRA) is to ensemble reanalyses produced within Co-authors reanalysis productions. There are produce ensembles of European regional UERRA. Andrea K. Kaiser-Weiss (Deutscher examples for each regional reanalysis atmospheric reanalyses of Essential Wetterdienst), Michael Borsche outperforming the other ones at certain Climate Variables thereby providing (Deutscher Wetterdienst), Frank Kaspar locations. estimates for the associated uncertainties Customizing the Weather (deutscher Wetterdienst) in the data sets. One of these data For special case studies, the comparison sets is the high resolution probabilistic Research and Forecasting Model Within the FP7 project UERRA with independent or dependent wind COSMO-EN-REA12 reanalysis (Bach for west Spitsbergen fjords (Uncertainties in Ensembles of Regional observations could hint on abilities and et al. 2016) which is based on the non- – wind hindcast ReAnalyses) several new large data sets limitations of each reanalysis system, hydrostatic limited-area model COSMO Author Szymon Kosecki are produced, mainly for the European which has to be investigated further. (COnsortium for Small-scale MOdeling). CORDEX domain. At their boundary, Here we give a first assessment of It is produced at 12-km grid spacing Affiliation Rok these regional reanalyses are driven uncertainties in UERRA’s regional and with hourly resolution covering the Co-authors similarly by ERA-Interim (and ERA-40 for reanalyses with the intention to guide CORDEX-EUR11 domain. The applied S.K. Szymon Kosecki Centre for Polar years before 1979). The various regional potential users. ensemble data assimilation method Studies, K.S.A. Kjetil Schanke Aas reanalyses employ different regional is an ensemble nudging scheme. In University of Oslo, J.J. Jaromir Jakacki, models: UM by UKMO, HARMONIE by this scheme, an ensemble of different L.D.G. Lidia Dzierzbicka-Głowacka SMHI, MESCAN by MeteoFrance and deterministic nudging realizations is COSMO by DWD. generated by perturbing the observations with perturbations reflecting the observation errors. A major benefit of this

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 95 Section 4

The state-of-the-art Weather Research Therefore the dedicated To this end, we use a 5-member set and Forecasting Model has been parameterizations have been applied. of 7-month reforecasts made over the Energy budgets and transports: applied for the West Spitsbergen fjords: The presentation points up the period 1981-2014, and compare with global evolution and spatial Hornsund and Kongsfjorden. problem of lack of topographic data the Japanese 55-year Reanalysis (JRA- patterns during the twentieth for Arctic regions and unreliability of 55) dataset. Strong and weak vortex Parameters such as: surface pressure, century as estimated in two existing ones. The simulations were events are classified into short (less relative humidity, 2-m air temperature and performed for January 2010. The chosen than 10 days) and long (no less than AMIP‐like experiments 10-m wind speed have been simulated parameterizations will be applied for long 20 days) events, and each category is for the purpose of further implementation Author Valerio Lembo term 2010-2015 hindcast. composited. in fjord –ocean water circulation, Affiliation University of Hamburg hydrodynamic model. Special emphasis In particular, we examine how the Co-authors was put on obtaining proper wind Duration and Decay of Extreme characteristics of each category (i.e. D Folini (ETH Zürich), M Wild (ETH conditions. Vortex Events in the Polar frequency of occurrence, anomalous Zürich), P Lionello (Università del Salento) winds and E-P fluxes) are represented Results from simulations with different Stratosphere: Comparison of in the forecast model in comparison to The 20th century evolution and spatial reanalysis data sets used for the the ECMWF Seasonal Forecast the reanalyses. Obviously, long WVEs patterns of the Top-of-Atmosphere boundary condition: ECMWF – Era Model with Reanalyses (SVEs) tend to be accompanied by longer (TOA), atmospheric, and surface energy Interim and NCEP – Climate Forecast enhancement (suppression) of upward- budgets (EB) are investigated in this System Reanalysis (CFSR) have been Author Yvan Orsolini propagating planetary wave than their work. Total, atmospheric and oceanic compared. The results have been NILU – Norwegian Affiliation short counterparts. Both types begin in meridional energy transports are also validated against observations performed Institute for Air Research the same fashion with a barotropic zonal computed from the EBs. in the Polish Polar Station in Hornsund Co-authors wind anomaly extending from 1 hPa to and measurements conducted in the Two AMIP-like ensemble simulations Yvan Orsolini (NILU), Kazuaki Nishii (Mie the lower stratosphere, but in the latter Bayelva/Ny-Ålesund in Norwegian are considered: Integrated Forecast University), Hisashi Nakamura (University case, sustained wave forcing from the synoptic station. Preliminary results System (IFS) simulations of the ERA- of Tokyo) upper-troposphere allows for persistence show good agreement with 2-m 20CM experiment, and ECHAM5-HAM and further downward propagation of the temperature, relative humidity, surface We investigate extreme stratospheric model simulations. With the latter, wind anomalies. pressure. However results show high bias polar vortex events in the operational additional sensitivity experiments are associated with higher wind speeds. seasonal forecast model (System 4) of However, short WVEs uniquely show an carried out by constraining either Sea- the European Centre for Medium-Range E-P flux divergence anomaly dominated Surface Temperatures (SST) and Sea-Ice For the sake of large wind impact on Forecasting (ECMWF) in comparison by its meridional component in their Cover (SIC) or aerosol concentrations to the water circulation in fjord, especially to re-analysis data during the Northern ending phase, which suggests that climatological values. due to the phenomena of “topography Hemisphere winter. While previous barotropic instability abruptly terminates tunnelling” along the fjord axis, further The recent decades estimates of the studies have documented both weak these events. The characteristics studies have been performed considering EB are in reasonable agreement in the vortex events (WVE) and strong vortex of precursory upper-tropospheric specially attention on the wind field. two models, while they are not for what events (SVE) in models or re-analyses, disturbances are also examined for each The problem has been diagnosed as concerns the global scale evolution. there has been little focus on the category, in both the seasonal forecast a bad representation of subgrid-scale Particularly, in the 1970s ERA-20CM duration of these events and their decay model and the reanalyses. orographic effects. shows a fast transition from negative to processes. positive EBs at Top of Atmosphere (TOA) that is not found in ECHAM5-HAM.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 96 Section 4

The impact of aerosols, as evidenced five radiosonde data sets and seven data sets is very small and shows the (1981–2010), and a good representation by the sensitivity experiments with reanalysis products beginning in 1989. trend in better agreement with each other of sub-decadal variability. However, ECHAM5-HAM, sets up an inter- The results show that the magnitude in the troposphere. the representation of pre-1950 inter- hemispheric gradient in the TOA and of warming or cooling depends on the decadal snowvariability is questionable, surface budget after 1960, increasing data sources, atmospheric heights, and since reanalysis products diverttowards the total poleward transport in the geophysical latitudes. Over low-middle Eurasian snow depth in long- different base states. Northern Hemisphere and decreasing latitudes, the cooling varies from -2.6 K/ term climate reanalyses Limited availability of indepen-dent it in the Southern Hemisphere. This decade in NCEP-DOE to -0.8 K/decade Author Martin Wegmann long-term snow data makes it difficult to feature is not found in ERA-20CM, in HADAT2 in the lower stratosphere. University of Grenoble assess the exactcause for this bifurcation suggesting a substantial difference in the The warming weakly changes from 0.2 Affiliation in snow states, but initial investiga- representation of the aerosol forcing in through 0.4 K/decade in the middle Co-authors tions point towards representation of the two experiments. troposphere. Martin Wegmann (University of Grenoble), Yvan Orsolini (NILU), Olga the atmosphere rather than differences SST variations do not seem to induce Over Antarctica, there is a pronounced Bulygina (7All-Russian Research Institute in assimilated data or snow schemes. long-term variations in the patterns of warming in the low-middle troposphere of Hydrometeorological Information – Thisstudy demonstrates the ability of TOA budget and related total meridional in the three NCEP reanalyses and the World Data Centre), Alexander Sterin long-term reanalysis to re-produce snow transport. On the contrary most of RATPAC radiosonde data sets, and (7All-Russian Research Institute of variability accordingly. the surface and atmospheric budget cooling in the other eight products. Over Hydrometeorological Information – World and transport inter-annual variability the Arctic, the warming is observed Data Centre), Stefan Brönnimann is attributable to the evolution of SST, from the lower troposphere to the lower (University of Bern) and much more agreement is observed stratosphere in all twelve data sets. among the two models in this respect. Significant cooling is identified over the Snow cover variability has significant middle stratosphere (above 50 hPa) in all effects onlocal and global climate five radiosondes. evolution. By changing surface en-ergy Ensemble Spread and Its fluxes and hydrological conditions, For global mean temperature, the trend Implication for the Evaluation changes in snowcover can alter is approximately 0.2 K/decade in the of Temperature Trends from atmospheric circulation and lead to troposphere and −0.8 K/decade in the remoteclimate effects. To document such Multiple Radiosondes and stratosphere. The spread increases multi-scale climate ef-fects, atmospheric Regional Reanalyses Products significantly with atmospheric height reanalysis and derived products offer from approximately 0.1 K/decade at Author Jianjun Xu theopportunity to analyze snow variability 850hPa to 0.8 K/decade at 30hPa. The Guangdong Ocean in great detail farback to the early 20th Affiliation spread in the reanalyses data sets is University century. much larger than in the radiosondes in Co-authors the stratosphere. In contrast, the spread So far only little is know abouttheir J. Xu (Guangdong Ocean University) in both the reanalyses and radiosondes quality. Comparing snow depth in four long-term re-analysis datasets with Based on the ensemble spread, a Russian in situ snow depth data, wefind methodology of measuring uncertainty in a moderately high daily correlation weather forecasts, the temperature trend (around 0.6–0.7), which is comparable and spread have been estimated using to correlations for the recent era

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 97 Section 4

spectra. The brightness temperature differences seen in the comparison of models and GCM informed statistically Evaluate reanalysis with (BT) differences between AIRS and the reanalysis data, ARM sounding profiles downscaled models for a data scare simultaneous in-situ and satellite synthetic spectra based on the ARM- and AIRS-L2 physical retrievals. But such region of Nepal’s Karnali basin. SGP are used to establish observation radiance comparisons clearly disclose observations: bracketing the We tested the performances of CORDEX uncertainties. MERRA-2 and ERA-interim the biases in the middle and upper observational uncertainties South Asia data and downscaled at data at the same 51 occasions are also troposphere and avoid any uncertainties the station scale using the SDSM 5.2 Author Xianglei Huang used generate synthetic AIRS spectra. associated with level-2 retrievals. (Decision Centric) by providing the GCM Affiliation The University of For AIRS channels in the CO2 band informed climate scenarios. We validated Michigan sensitive to the temperature from Evaluating Dynamically and the CORDEX data performances with the Co-authors surface to 800hPa but not to water Statistically Downscaled Climate APHRODITE 0.05 degree climate surfaces Xiuhong Chen (the Univ. of Michigan), vapor, both reanalyses show negative Model for Monsoon Rainfall available since 1961 and the SDSM5.2 Xianglei Huang (the Univ. of Michigan), differences from the AIRS observation model’s performances with the observed Norman G. Loeb (NASA/Langley), Xiquan and such differences are much larger Extreme: A Case from Data rainfall monitoring data available since Dong (Univ. of Arizona), Baike Xi (Univ. than the observation uncertainties (OU) Scarce Region in Western Nepal 1981. of North Dakota), Erica Dolinar (Univ. established above. For channels sensitive Author Jeeban Panthi of North Dakota), Michael Bosilovich to temperature from 400-200hPa, The Small Earth Nepal (NASA/GSFC), Seiji Kato (NASA/Langley), the MERRA-AIRS difference is much Affiliation Evaluating global radiation of (SEN) Paul Stackhouse(NASA/Langley), William smaller than the OC while the ERA-AIRS regional reanalyses over Europe Smith Jr. (NASA/Langley) difference is comparable to the OU. Co-author against the satellite-derived Jeeban Panthi (The Small Earth Nepal) SARAH dataset Every observation has its own For channels sensitive to temperature uncertainty. This naturally leads to a between 800 and 400 hPa, reanalysis It is well agreed that the climatic extremes Author Michael Borsche and AIRS difference is smaller than question in the evaluation of reanalysis events are increasing in last few decades Affiliation Deutscher Wetterdienst against observations: how good is good or comparable to the OU. The BT and many climatic models have predicted Co-authors enough? Here we answer this question differences between both reanalyses that those events will increase in future. M. Borsche (Deutscher Wetterdienst), A. by using two independent observations and AIRS are negative and significantly There are is an agreement among the K. Kaiser-Weiss (Deutscher Wetterdienst), to bracket observation uncertainties, larger than the OU for the channels in climate models on the future increase in F. Kaspar (Deutscher Wetterdienst) and then using such uncertainties in the H2O band. Such differences cannot temperature, however in case of rainfall, be explained by temperature difference the evaluation of MERRA-2 and ERA- there is a high uncertainty. The global Within the European Framework alone. The only possible explanation is interim reanalysis. Using cloud radar climate models are downscaled either Programme 7 project UERRA that both reanalyses have positive biases observations, we have identified 51 by using the local topography (dynamic) (Uncertainties in Ensembles of Regional for the water vapor from 800 to 200 hPa. occasions from 2004 to 2013 when AIRS or by establishing a relationship of local Reanalyses) several regional reanalyses on NASA Aqua flied over the ARM SGP Similar positive humidity biases can weather with the large scale atmospheric are produced. The grid size resolution of site with no cloud in a 30km-by-30km be seen for the comparisons between phenomenon (statistical). the reanalyses is comparable to the one proximity. reanalyses and AIRS over the 30-40N In this paper we attempt to analyze the of the satellite-derived solar radiation Using the ARM SGP soundings, we then zone, indicating that it is a systematic monsoon rainfall extreme events with the estimate SARAH v002 produced by CM computed synthetic AIRS spectra and bias instead of any coincidence over the dynamically downscaled regional climate SAF (Satellite Application Facility on compared them with observed AIRS ARM site. We further show that such Climate Monitoring). differences in BT are consistent with the

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 98 Section 4

In this study we compare solar radiation balance and the related hydraulic works surface forecast for soil moisture at four ensemble means of all reanalyses suffer of all regional reanalyses of that project for water supply, it is crucial to correlate levels (0-7; 7-28; 28-100; and 100-289 cm from a non-physical reduction of the (from the National Meteorological quantitatively climate trends, precipitation from the ground level, respectively). number of degrees of freedom originating Services of Sweden (SMHI), Great and groundwater behaviour. In this paper, from the large spread of the ensemble The ultimate goal of this research is Britain (UKMO), France (Météo France), the use of global atmospheric datasets members. to check whether the global datasets and Germany (DWD)) with the satellite as a reliable tool for water resources – specifically the behaviour of the soil On the contrary, ensemble members estimate on instantaneous to multi- management is further explored. moisture volumetric content – may allow of different datasets show significant decadal time scales within the period In fact, in a previous paper (Cerlini et estimating the available groundwater shits of the dynamical proxies over time. 1982 to 2014. In order to estimate the al., 2017), ERA-Interim reanalysis of resources at a regional scale. These shifts are however not coherent added value of the regional reanalyses meteorological observations made by among different reanalyses datasets. compared to existing global reanalyses, the European Centre for Medium-Range A comparison with large ensemble the global radiation of ERA-Interim is Weather Forecasts (ECMWF) have Evaluating the coherence of of climate models is also presented. included into this study. been compared to the local water table reanalyses’ North Atlantic The effects of the seasonal cycle are measurements given by the monitoring atmospheric circulation using analysed. Evaluating groundwater network managed by the Regional dynamical proxies Agency for Environmental Protection resources by means of global Author Davide Faranda Evaluating the Discrepancy in datasets of the Umbria Region (ARPA Umbria Italy). The pointed out good correlation Affiliation CNRS (LSCE CEA- Gridded Rainfall Datasets over Author Paolina Bongioannini between the trend of soil moisture Saclay) Eastern Africa for Assessing Cerlini – the result of precipitation over all Co-authors Model Performance and Affiliation Centre for Climate and meteorological space-time scales – and D Faranda (LSCE-CNRS CEA Saclay, Understanding Climate Change Climate Change, local water table data of unconfined France), MC Alvarez-Castro (LSCE-CNRS Hussen Seid Endris University of Perugia aquifers authorises further in-depth CEA Saclay, France), D Rodriguez Author analyses. Affiliation IGAD Climate Prediction Co-authors (LSCE-CNRS​ CEA Saclay, France), G and Applications Centre P. Bongioannini Cerlini (Centre for In the line with such promising results, in Messori (MISU Stockolm, Sweden), P (ICPAC) Climate and Climate Change, University this paper meteorological observations Yiou (LSCE-CNRS CEA Saclay, France) Co-authors of Perugia), S. Meniconi (Centre for from ERA-Interim and ERA5 reanalyses We evaluate the coherence of the Climate and Climate Change, University are compared with the aim of evaluating: HS ENDRIS (IGAD Climate Prediction dynamical properties of atmospheric and Applications Centre – ICPAC) of Perugia), B. Brunone (Centre for i) the effect of the different models circulation over the North Atlantic for Climate and Climate Change, University and procedures used to obtain global several reanalyses datasets (20CR, Reliable observed rainfall dataset of Perugia) datasets, and ii) the role played by ERA20CM, CERA20C, NCEP-NCAR). is crucial for evaluating the model the characteristics of data on which performance and assessing and Climate change influences the reanalyses are based (e.g., their temporal We measure the instantaneous metrics understanding climate change. In many hydrological cycle with direct effects and spatial resolution). Attention is defined in Faranda et al. (Scientific parts of the world, however, observed on groundwater resources, one of focused on the behaviour of water fluxes Reports, 2017), namely the number of rainfall records are often scarce, the most important supply source for towards water table as a preliminary degrees of freedom and the persistence human consumption and irrigation. phase of the water budget assessment. of daily averaged sea-level pressure In the framework of assessing water In fact, reanalyses produce the land fields. We find that, before 1948, the

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 99 Section 4 discontinuous and contain discrepancies. SAT analyses, and two dynamically Version 2) and MERRA2 (the second This is particularly true for many areas/ Evaluation of atmosphere- downscaled reanalyses (Reeves Eyre and Modern-Era Retrospective analysis for regions in Eastern Africa. (ocean, land, glacier) surface Zeng 2017). Research and Applications) over this steep terrain region. The lack of spatially and temporally interactions in reanalysis Finally, we used direct covariance latent continuous rain-gauge datasets over products heat and sensible heat fluxes and inertial- The stations vary from 520m to 2900m in the region makes difficult for evaluating dissipation wind stresses measured the altitudes, providing comprehensive Author Xubin Zeng climate model simulations and from twelve cruises over the tropics observations in the basin and in the understanding climate change. Affiliation University of Arizona and mid- and high latitudes to evaluate highland. The root mean-square errors Co-authors ocean surface turbulent fluxes from six (RMSE) of relative humidity, meridional In this study, the discrepancy between reanalyses, four satellite-derived flux wind, zonal wind show general similarity various gridded observational datasets Patrick Broxton (University of Arizona), products, and two combined products between observations and the three over the Eastern Africa has been Michael Brunke (University of Arizona), (Brunke et al. 2011). global datasets. assessed. Six gridded rainfall datasets Jack Reeves Eyre (University of Arizona) (namely CRU, GPCC, GPCP, UDEL, In terms of relative humidity, the RMSE Atmosphere-ocean-land-glacier interface ERA-INTERIM and NCEP) are analyzed is about 10%-20% below 400hPa, and processes strongly affect weather and Evaluation of CFSv2, ERA- and compared against high-resolution raises to 30% at higher levels. The RMSE climate prediction and the energy/water/ Interim and MERRA2 datasets (5km) “home-generated” gridded data of wind is 1.0-4.5m/s. The temperature carbon cycles. Throughout the years, with intensive radiosonde data in (i.e ICPAC-CHIRPS), which is available observations of three sites show a good we have done comprehensive evaluations at 1981 to present. Different statistical the lee of the Tibetan plateau consistent against CFSv2, ERA-Interim, of these interface processes in various performance measures (such as spatial except for the 2165m high site Jinchuan, reanalysis products. In this presentation, Author Zhiwei HENG and temporal correlation, bias, root mean which shows a peak RMSE about 8k at we will summarize our recent work in Affiliation Institute of Plateau square error and standard deviation) 200hPa level. this area. Meteorology, China applied to quantify the uncertainty Meteorological The RMSE between temperature in gridded observational datasets. First, we have developed a new and Administration, Chengdu observation and MERRA2 is about 4k The analysis indicated that large innovative method to obtain daily 4 than those of CFSv2 and ERA-Interim. discrepancies exit among the different km snow water equivalent and snow Co-authors It is also found that, the observations of observational datasets. It is also found depth data from 1981 to present over Z.W. HENG (Institute of Plateau the lower altitude sites are relatively more that the performance largely depend on continental United States. Using this Meteorology, CMA) similar than higher sites. dataset, we have found large snow water the season, sub-region and metrics used. The intensive Southwest China vortex equivalent and snow depth errors from This analysis very useful to highlight observation experiment is conducted reanalysis and land data assimilation the differences in spatial and temporal in Sichuan province (in the lee of the systems, and identified the primary rainfall estimates and also provide Tibetan Plateau), from 21 June to 31 July reasons (Broxton et al. 2016). guidance to the choice of gridded in recent years. This study collects about rainfall data for assessing the model Second, we used extensive in-situ 2-m 1900 high-quality radiosonde data from 4 performance and understanding climate air temperature measurements (~1400 of the meteorological stations, from 2014 change over the region. station-years) over Greenland to assess to 2016, to evaluate the quality of the monthly mean temperature from seven commonly used global datasets ERA- global reanalysis datasets, four gridded Interim (interim ECMWF Re-Analysis), CFSv2 (NCEP Climate Forecast System

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 100 Section 4

Such classifications define a few to extract the tidal components and an Evaluation of circulation type distinguished circulation types (CTs), Evaluation of diurnal tidal activity effort is made to validate the MERRA classifications in five global to which daily patterns are classified in the MERRA reanalysis winds reanalysis tidal fields using 3-hourly reanalyses over selected Euro- according to a similarity measure. So using radiosonde observations radiosonde observations. Under Tropical Atlantic and South-American far, no study has aimed at comparing over a tropical station Tropopause Dynamics (TTD) Experiment- classifications (e.g., CT occurrence CAWSES-India programme, we have domains in winter frequencies) in multiple reanalyses, Author Subrahmanyam Kandula conducted intense observations for three Author Jan Stryhal and, in general, the effect of reanalysis Affiliation ISRO consecutive days in each month using selection on results has been rather 3-hourly radiosonde launches during Affiliation Charles University Co-authors marginalized. The present research December 2010 to November, 2013 from K.V. Subrahmanyam (Space Physics Co-authors focuses on quantifying the differences in Trivandrum (8.5, 76.9E). Laboratory,VSSC, ISRO, Trivandrum), Jan Stryhal (Department of Physical CT frequencies in five global reanalyses Karanam Kishore Kumar (Space Physics In the present study, we have Geography and Geoecology, Faculty of (ERA-40, NCEP-1, JRA-55, ERA-20C, Laboratory,VSSC, ISRO, Trivandrum), comprehensively evaluated the MERRA Science, Charles University, Prague, 20CRv2) during 1961–2000 winters. Czech Republic; Institute of Atmospheric S.V.Sunilkumar (Space Physics reanalysis tidal fields in zonal and Physics, Academy of Sciences of the We focus on two spatial domains,– Laboratory,VSSC, ISRO, Trivandrum), meridional winds using radiosondes Czech Republic, Prague, Czech Euro-Atlantic and South-American–, Geetha Ramkumar(Space Physics derived winds over Trivandrum. The Republic), Radan Huth (Department of each represented by several smaller Laboratory,VSSC, ISRO, Trivandrum) regression analysis between radiosonde Physical Geography and Geoecology, subdomains covering regions with derived tidal winds with MERRA reanalysis Atmospheric reanalysis produces various Faculty of Science, Charles University, various climates and numbers of form surface to 25 km height with an physical parameters for estimation of Prague, Czech Republic; Institute of observations assimilated by reanalysis interval of 1 km is performed to quantify the state of the Earth’s atmosphere Atmospheric Physics, Academy of models. Furthermore, for selected the degree of correlation between the and for a better understanding of the Sciences of the Czech Republic, Prague, subdomains, it will be shown how two datasets. The results show that underlying dynamical processes. Modern Czech Republic) the choice of the reference reanalysis the temporal variations of zonal wind affects validation of models by ranking Era Retrospective Analysis for Research represented very well in MERRA, while Atmospheric reanalyses have been 32 CMIP5 GCMs according to their and Applications (MERRA) provides meridional wind shows some discrepancies widely used in synoptic-climatology to skill to simulate the winter CTs. A total assimilated data with 3-houlry intervals as compared to radiosondes. study large-scale atmospheric circulation of eight classification methods will be which can be effectively used to analyse After systematic evaluation of MERRA and its links to local weather and used in parallel to minimize the effect of the atmospheric processes on a diurnal wind fields, we have extracted the climate, including the role that changes subjective, unavoidable methodological scales, such as atmospheric tides. monthly mean diurnal tide amplitudes in circulation play in trends of climatic choices on results. These tides are one of the most of zonal and meridional wind using variables, and to evaluate outputs of prominent features observed in most of climate models. In this kind of research, MERRA, which also showed a good the geophysical parameters and they play correspondence with radiosonde automated classifications of daily mean a vital role in the dynamics and energetics sea level pressure or geopotential height observations. It was interesting to note of the atmosphere. However, longitudinal that in the lower atmosphere the peak patterns represent one of the most wind observations are needed to distinct prominent approaches. diurnal amplitude occurs during June- the migrating and non-migrating tidal July-August months with secondary components. In the Present study peak during winter at 15 km altitude. MERRA 3-hourly wind fields are used Though, the above results did not

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 101 Section 4 differentiate between migrating and In this study performance of ERA-Interim To investigate the sensitivity of the assimilates only conventional surface non-migrating diurnal tides, the peak (Dee et al., 2011) and CCMP (Atlas et wave model to the wind field, several and upper air observations, with no use amplitudes of diurnal tides observed al., 2011) wind fields were evaluated for wave simulations in the period of of satellite observations, using the same in the lower atmosphere during Indian wave simulation in the Persian Gulf. One 1/10/2009-7/7/2010 were carried out data assimilation system as the JRA-55. summer monsoon months could be of the shortcomings in the Persian Gulf using WAVEWATCH III model forced The project, which name is “JRA- attributed to the non-migrating tides as region is the lack of sufficient measured with ERA-Interm and CCMP wind 55 Conventional (JRA-55C)”, aims to this is dominated by large amount of overwater wind data as well as results fields. Application of CCMP wind field produce a more homogeneous dataset latent heat release over the East Asian of atmospheric numerical models which compared to ERA-I wind field sometimes over a long period, unaffected by region. Over all, the tidal fields derived specifically calibrated for this region. results in larger wave height and changes in historical satellite observing from MERRA and radiosonde show very sometimes vice versa. To evaluate the Therefore, it is common that the forcing systems. In addition, JRA-55AMIP, good agreement. The significance of performance of applied wind fields, the wind data for wave models are derived which is the AGCM experiment, is the present study lies in evaluating the simulated and measured significant wave from the global wind resources such as also conducted. In the experiment, the MERRA reanalysis diurnal tidal fields in height (Hs) and peak spectral period ECMWF (European Center for Medium same model and the same boundary the troposphere and lower stratosphere (Tp) were compared and error indices range Weather Forecasting). To do so, such as the observed SST and sea-ice, using radiosonde observations. were calculated. Results indicated that wind rose from measurements, ERA- greenhouse gases, ozone and aerosols application of ERA-I and CCMP led to an Interim and CCMP wind were compared as in the JRA-55 and JRA-55C, are average underestimation of 30% for Hs in Lavan and Siri islands stations located prepared. Evaluation of ERA-Interim and and 10% for Tp in both stations. in the northern Persian Gulf in the period CCMP wind fields for wave We evaluated JRA-55C by comparing of 1/10/2009-7/7/2010. simulation in the Persian Gulf these three datasets, JRA-55, JRA-55C The measured wind data are collected Evaluation of JRA-55C, an and JRA-55AMIP. The main results are Author Mohammad Hossein from synoptic stations located on islands Atmospheric Reanalysis as follows. On the basis of forecast skill, Kazeminezhad and may affected by the land. Therefore, Assimilating Conventional the quality of the JRA-55C is inferior to Affiliation Iranian National Institute the recorded wind speeds may be smaller Observations Only that of the JRA-55, but the JRA-55C has for Oceanography and than those occurred overwater. The most better temporal homogeneity than the Atmospheric Science frequently occurring wind speed in both Author Chiaki Kobayashi JRA-55. The climatological properties Co-authors stations was in the range of 2.5-5.0 m/s. Affiliation Meteorological Research of the JRA-55C are similar to those of Mohammad Hossein Kazeminezhad As can be seen, almost in all wind speed Institute the JRA-55 in the troposphere and lower (Ocean Engineering and Technology ranges, there is a better agreement Co-authors stratosphere, except for high southern Research Center, Iranian National between the frequency of occurrence of C Kobayashi (Meteorological Research latitudes. QBO is properly represented Institute for Oceanography and CCMP and measured wind speeds. For Institute), H Endo (Meteorological in JRA-55C, which is not appeared in Atmospheric Science, Etemad Zadeh St., wind speed above 10 m/s, occurrence Research Institute), H Kamahori JR A55AMIP. Fatemi Ave., Tehran 14155-4781, Iran. frequency of ERA-I and CCMP winds (Meteorological Research Institute) The pattern correlation of spatial Tel: +98 21- 66944873, are much less than that of the measured precipitation anomaly of JRA-55C Fax: +98 21- 66944869 winds, such that, there is no wind speed As a subset of the Japanese 55- shows temporal homogeneity through e-mail: [email protected]) above 12.5 m/s from ERA-I and CCMP year Reanalysis (JRA-55) project, the the reanalysis period. The radiation datasets in the Lavan station. Meteorological Research Institute of the Japan Meteorological Agency conducted balance of JRA-55 and JRA-55C has a global atmospheric reanalysis that characteristics similar to those of JRA-55

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 102 Section 4

AMIP (model). Therefore, improvement Project (ORA-IP) for, among other things, re-analyses, as well as downscaling of the radiation balance of the model is establishing a protocol for the next Evaluation of precipitation in procedures based on these re-analyses, reflected directly in the balance of the intercomparison exercise, discusssing UERRA regional re-analysis are calculated for the past 30-50 years. reanalysis field. strategies for the near real-time extension datasets for complex terrain With respect to precipitation, regional of the current reanalyses and identifying regions re-analyses are expected to better recommendations and good practices for represent high threshold events than Evaluation of Ocean Syntheses: the reanalysis production. Author Cristian Lussana global re-analysis. The aim of the present a COST Action to improve our Affiliation the Norwegian knowledge about ocean EOS intends to provide a uniform study is to evaluate daily precipitation protocol for the evaluation of ocean Meteorological Institute data from the new regional re-analyses of syntheses and reanalyses syntheses, and seek adhesion to this Co-authors UERRA in two topographically complex Author Aida Alvera Azcarate protocol from scientists working on C. Lussana (Norwegian Meteorological sub-regions of Europe, namely the ocean reanalyses worldwide. This work Institute, Oslo, Norway), F. Isotta (Federal European Alps and Fennoscandia. Affiliation University of Liege builds-up on previous efforts made within Office of Meteorology and Climatology Our focus is on aspects of re-analysis Co-authors the GODAE and ORA-IP initiatives for MeteoSwiss, Zurich, Switzerland), B. uncertainty that may be relevant for A.Alvera-Azcárate (University of Liege, intercomparisons. The metrics proposed Casati (Meteorological Research Division, hydrological applications, notably Belgium), M. Drevillon (MERCATOR need to facilitate the assessment Environment and Climate Change the dependence on spatial scale. In Ocean, France), K. Haines (University of of progress in the quality of ocean Canada, Dorval (QC), Canada), C. Frei comparison with verification of numerical Reading, UK), S. Masina (CMCC, Italy), reanalyses. Detailed metrics are needed (Federal Office of Meteorology and weather predictions, the evaluation of K.A. Peterson (Metoffice, UK), A. Storto also for regional ocean reanalyses and Climatology MeteoSwiss, Zurich, reanalysis data must focus more on (CMCC, Italy) for process-based intercomparisons. Switzerland), O. E. Tveito (Norwegian assessing the spatial smoothing and Meteorological Institute, Oslo, Norway) The COST Action “Evaluation of Ocean This protocol, still under development, filtering properties of the atmospheric and L. Cantarello (Norwegian Syntheses” (EOS) was initiated in 2014 will be presented at the conference in model considered, while the forecast Meteorological Institute, Oslo, Norway)(2) in order to establish and consolidate a order to foster discussion and obtain error is less relevant because it is Federal Office of Meteorology and network of European scientists working feedback from reanalysis experts. The expected to be rather small due to the Climatology MeteoSwiss, Zurich, on the generation and evaluation of main achievements of the EOS network frequent data assimilation cycles. Switzerland, (3) ocean syntheses and reanalyses. The and a brief presentation of the activities The evaluation is based on a comparison main goals of EOS are to improve the organised in the following months will be Re-analysis aims at providing long- against conventional climatological coordination of the European efforts in also presented. term, high-resolution, dynamically datasets derived from spatial analyses the evaluation of ocean syntheses, to consistent climate datasets useful for optimize their use and value, to ease their of high-resolution rain-gauge networks. environmental applications. Usually, The Alpine rain-gauge dataset covers access, to promote their improvement these datasets cover a time period of and to raise confidence in their quality. territories of seven countries and several decades and they assimilate encompasses more than 5300 daily Through the activities organised by high-quality and detailed observations rain-gauge observations on average. the network, regional intercomparison into the atmospheric analysis. In UERRA, In Fennoscandia, we focus on Norway, initiatives of ocean reanalyses have been a FP7 research project of the EU, several Sweden and Finland where a dataset started (polar regions, Atlantic Ocean). regional deterministic and ensemble of approximately 2000 daily rain-gauge EOS is also co-organising future plans observations is available. of the Ocean Reanalysis Comparison

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 103 Section 4

Our evaluation strategy combines temporal changes from a combined “standard” verification measures of Evaluation of representation of Evaluation of steric sea level use of ocean observing systems and systematic errors (such as the bias and atmospheric circulation and from the CMEMS ensemble of numerical model techniques. root mean squared deviations) with climate variability in the JRA-55 ocean reanalysis In this analysis we will present results spatial verification methods, which reanalysis on the evaluation of global and regional account for the presence of features and Author Andrea Storto ocean steric sea level under the Ocean for the coherent spatial structure inherent Author Yayoi Harada Affiliation CMCC State Report activity from a multi- in precipitation fields, and provide Affiliation Meteorological Research Co-authors reanalysis approach based on an enhanced diagnostics (e.g. scale- Institute/Japan Andrea Storto (CMCC), Karina von ensemble product of the Copernicus separation approaches inform on the meteorological Agency Schuckman (Mercator-Ocean), Marine Service. scale-structure and scale-dependence of Co-authors Magdalena Balmaseda (ECMWF), the error). In addition, consistency checks through Y. Harada (Meteorological Research Clement Bricaud (Mercator-Ocean), physical budget constraints with the Scale dependence of the uncertainty/ Institute/ Japan meteorological Agency) Charles Desportes (Mercator-Ocean), combined use of climate observing accuracy is examined in our analyses Marie Drevillion (Mercator-Ocean), Yann systems and reanalyses are performed by considering (nested) hydrological This study investigates the quality of Drillet (Mercator-Ocean), Clotilde Dubois as they have a large potential to deliver catchments of variable size and by the Japanese 55-year Reanalysis (JRA- (Mercator-Ocean), Gilles Garric a robust uncertainty assessment decomposing precipitation fields into 55, Kobayashi et al. 2015), which is the (Mercator-Ocean), Laura Jackson (UK and to shed new light on unresolved (orthogonal) wavelets of variable scale. second global reanalysis constructed by MetOffice), Matt Martin (UK MetOffice), climate science issues. In particular, A difficulty for an unbiased evaluation the Japan Meteorological Agency (JMA), Simona Masina (CMCC), Sandrine Mulet complementary information coming of re-analyses is that reference comparing with other reanalyses and (CLS), Coralie Perruche (Mercator- from altimetry and gravimetry satellite datasets themselves are subject to observational datasets. Improvements Ocean), Isabelle Pujol (CLS), Drew missions is helpful for qualifying the uncertainties, the magnitude of which were found in the representation of Peterson (UK MetOffice), Patricia de reanalysis datasets. For this purpose, may be significant at the resolution of atmospheric circulation on the isentropic Rosnay (ECMWF), Richard Wood (UK the sea level budget has been applied, modern re-analyses and, hence, could surface and in the consistency of MetOffice), Hao Zuo (ECMWF) allowing an assessment of the multi- affect a scale-dependent evaluation. momentum budget based on the mass- Thermal expansion of seawater is a major reanalysis approach and the reliability of This difficulty is addressed in the Alpine weighted isentropic zonal mean (MIM) driver of global mean sea level change. the ensemble mean. section of our analysis by introducing method. Quantifying the effect of the seawater a new probabilistic rain-gauge dataset The representation of climate variability density changes on sea level variability is which explicitly quantifies uncertainties in several regions was also examined. of crucial importance for climate change by ensembles. The results indicate that JRA-55 studies, as the cumulative sea level generally improved the representation rise can be regarded as an important of phenomena on a wide range of climate change indicator, as well as space–time scales, such as equatorial being of direct societal importance. waves, compared with JRA-25 during the Ocean reanalysis systems are critical for satellite era, and improved the temporal the evaluation of this ocean monitoring consistency compared with the older indicator as they deliver a 3-D view reanalyses throughout the reanalysis on the interior of our oceans and its period, although some issues in JRA-55 were also identified.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 104 Section 4

For comparison purposes, we perform streams does lead to a discontinuity in Evaluation of the ensemble the analyses on the 56 members and the assimilated ozone fields in MERRA-2, Evaluation of TIGGE ensemble reanalysis ability to reproduce the ensemble mean of the 20CRv2c making it not useful for studies in decadal precipitation forecast over iran reanalysis, as well as for another (secular) trends in ozone, this choice mechanisms leading European Author Saleh Aminyavari temperature extremes reanalyses products, ERA-20C and was made to prioritize demonstrating the NCEP, in order to properly estimate and value NASA’s high-quality research data Affiliation Islamic azad university of Author M. Carmen Alvarez- discuss the uncertainties and be capable in the reanalysis context. chaloos Castro to assess the ability of reanalyses to The MERRA-2 ozone is compared with Co-authors reproduce the mechanisms that lead to Affiliation Laboratoire des Sciences independent satellite and ozonesonde 1Saleh Aminyavari,2Bahram Saghafian, European temperature extremes. du Climat et de data, focusing on the representation of 3Majid Delavar 1 Department of l’Environnement (LSCE/ the spatial and temporal variability of Technical and Engineering, Chaloos IPSL/CEA-CNRS) Evaluation of the Ozone Fields in stratospheric and upper-tropospheric Branch, Islamic Azad University, Chaloos, Iran 2 Department of Technical Co-authors NASA’s MERRA-2 Reanalysis ozone. The comparisons show M. C. Alvarez-Castro, D. Faranda, P. agreement within 10% (standard and Engineering, Science and Research Yiou. (LSCE/IPSL, France) Author Steven Pawson deviation of the difference) between Branch, Islamic Azad University, Tehran, Iran 3Department of Water Resources Affiliation NASA GSFC MERRA-2 profiles and independent The atmospheric circulation is an satellite data in most of the stratosphere. Engineering, Tarbiat Modares University, important driver of temperature Co-authors Tehran, Iran K Wargan (NASA GSFC), G Labow (NASA The agreement improves after 2004, variability. Weather regimes are typical when EOS Aura data are assimilated. atmospheric circulation patterns GSFC), S Frith (NASA GSFC), N Livesey Nowadays, meteorological forecasts (NASA JPL), G Partyka (NASA GSFC) The standard deviation of the differences are produced using numerical models. obtained using a cluster analysis. Climate between the lower-stratospheric and decadal variability can induce changes Precipitation is one of the widely- The assimilated ozone product from the upper-tropospheric MERRA-2 ozone demanded meteorological factors in those frequencies. We investigate how Modern-Era Retrospective Analysis for and ozonesondes is 11.2% and 24.5%, the atmospheric circulation might have and Improvement on Quantitative Research and Applications, Version 2 respectively, with correlations of 0.8 Precipitation Forecasts (QPFs) is the evolved in the past century, focusing (MERRA-2), produced at NASA’s Global and above. This is indicative of a specifically on the weather regimes main objective of predication centers and Modeling and Assimilation Office (GMAO) realistic representation of the UTLS a major challenge for the meteorological associated with temperature extremes in is summarized. The reanalysis begins ozone variability in MERRA-2. After Western-Europe. research communities. In this study, in 1980 with the use of retrieved partial- 2004, the upper tropospheric ozone in numerical precipitation forecasts in The 20CR is the longest reanalysis column ozone concentrations from a MERRA-2 shows a low bias compared TIGGE database were evaluated using available that assimilates only surface series of Solar Backscatter Ultraviolet to the sondes, but the covariance with deterministic, dichotomous (yes/no) and pressure observations since 1851 Radiometer (SBUV) instruments on NASA independent observations is improved probabilistic techniques over Iran, period using an Ensemble Kalman Filter data and NOAA spacecraft. compared to earlier years. Case studies 2008-2016. demonstrate the integrity of MERRA-2 assimilation method, producing an Beginning in October 2004, retrieved analyses in representing important Inverse Distance Weighting (IDW) were ensemble of 56 members of reanalysis ozone profiles from the Microwave Limb fields. Therefore, the differences among features such as tropopause folds. adopted for interpolation of prediction Sounder (MLS) and total column ozone values, downscaled to the stations, at the 56 members provide an estimate of from the Ozone Monitoring Instrument the uncertainty for the reanalysis. lead times of 1 to 5 days. To enhance (OMI) on NASA’s EOS Aura satellite are the forecast quality, NWP values were assimilated. While this change in data post-processed by Bayesian Model

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 105 Section 4

Averaging (BMA) and constituted a grand Connecticut, Storrs, CT, USA), Emmanouil all products, incorporates differences in have tried to recognize a front given ensemble prediction. The results showed N. Anagnostou (Department of Civil and forcing, model space/time resolutions horizontally gridded variables on a that ECMWF, in most stations, had better Environmental Engineering, University of and assimilation procedures used in each specific pressure level through an scores. Furthermore, the evaluation of the Connecticut, Storrs, CT, USA) WRR product. automated computer algorithm. Then, results after the post-processing showed we have applied our approach to state- Thus, evaluation of the ensemble output that the quality of post-processed Availability of multiple global water of-the-art reanalyses; ERA-Interim, CFS, with respect to available long-term predictions was better than those of resources reanalysis (WRR) products and MERRA. We have analyzed the result hydrologic observations for rainfall, the raw predictions. In conclusion, the has provided a unique opportunity to from front recognition to get statistics streamflow and groundwater levels accuracy of the predictions made by advance understanding of terrestrial of front frequencies and front intensities allows us to assess the accuracy of the selected centers could be ranked as hydrologic processes at regions (defined by precipitation rate, upward current WRR products and the range of medium over Iran while post-processing where in situ information is sparse or wind, horizontal temperature gradient, associated uncertainty due to differences of predictions is recommended to nonexistent. Africa is a continent where convective instability and so on) and in forcing and model structure. Bias improve the quality. this aspect is particularly emphasized compared it across the reanalyses. We and uncertainty characteristics are because it is generally characterized will try to elaborate possible explanation presented as function of hydrologic by sparse hydrologic observations to a reason why the differences among variables and temporal scale (monthly, Evaluation of water cycle while at the same time there is need for the reanalyses exist. components in the Upper Blue efficiently managing water resources seasonal and annual). Results from this Nile basin based on an ensemble to enhance food and water security in analysis highlight the current strengths and limitations of available WRR datasets Global evaluation of ERA-Interim of water resources reanalysis the area. Managing water resources in a sustainable manner requires at the for analyzing the hydrological cycle and other global rainfall products. very least an adequate characterization and dynamics of East Africa region and estimates over land without Author Marika Koukoula of hydrological fluxes (precipitation, provide unprecedented information for both developers and end users in similar ground-based observations by Affiliation University of Connecticut streamflow, evapotranspiration, groundwater) and states (soil moisture) hydroclimatic regimes. using Triple Collocation Analysis Co-authors at monthly, seasonal and annual scale. Author Christian Massari Marika Koukoula (Department of Civil and In this work we present a comprehensive Environmental Engineering, University of Front statistics in modern Affiliation CNR evaluation of water cycle components Connecticut, Storrs, CT, USA), Efthymios for the Upper Blue Nile basin in Ethiopia reanalyses using an automated Co-authors I. Nikolopoulos (Department of Civil and Christian Massari (IRPI-CNR, Perugia, estimated from four state-of-the-art WRR front recognition over East Asia Environmental Engineering, University of Italy), Wade Crow (USDA – Hydrology products. Connecticut, Storrs, CT, USA), Zoi Dokou Author Eunho Choi and Remote Sensing Laboratory, (Department of Civil and Environmental Specifically, evaluation is carried out Affiliation Seoul National University Beltsville, Maryland), Luca Brocca Engineering, University of Connecticut, for two datasets produced through Co-authors (IRPI-CNR, Perugia, Italy) Storrs, CT, USA), Semu Moges NASA’s Land Data Assimilation System E Choi (Seoul National University), (Department of Civil and Environmental (LDAS) at global (GLDAS v2) and regional GH Lim (Seoul National University) Precipitation is a fundamental physical Engineering, University of Connecticut, (FLDAS) scale and two versions (tier process of the global hydrological Storrs, CT, USA), Amvrossios C. 1&2) of the global WRR product of the A front is one of most important part cycle, and its temporal and spatial Bagtzoglou (Department of Civil and EU Earth2observe project. Each product of weather and climate over East Asia, distribution has a significant impact Environmental Engineering, University of includes a multi-model ensemble output. bringing severe weather events such on many land applications. Acquiring The final ensemble output, considering as heavy rain, damaging winds. We accurate and real-time precipitation data

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 106 Section 4 is essential to researching the global Recently, Brocca et al. (2014) developed In Portugal, due to the extensive human hydrological cycle, mitigating worldwide a method for estimating rainfall from use of coastal areas, the natural and built Historical Southern Annular drought and flooding, simulating land satellite soil moisture observations coastal environments have been amongst Mode index derived from 20th surface hydrological processes, and based on the principle that the soil can the most affected. The analysis of the Century reanalysis and ERA 20 understanding global climate change. be treated as a “natural raingauge”. North Atlantic cyclone characteristics, C: an overview In contrast with classical satellite namely track, cyclogenesis, deepening Despite this importance, ground- precipitation products, this new bottom- rate and cyclolysis – based on the Author Mariana Barrucand based estimates of rainfall over land up approach attempts to measure rainfall cyclone detecting and tracking algorithm are scarce within Africa, Central Asia Affiliation Conicet/University of by calculating the difference between developed for the Euro-Atlantic region and South America hence, relying on Buenos Aires two successive SM measurements (Trigo, 2006) – as well as impacts, have these estimates for studying processes Co-authors derived from a satellite sensor. been extensively evaluated for case at large scales is often impossible. M. Barrucand (Departamento de Ciencias studies occurring during recent winters Satellite and reanalysis rainfall products de la Atmósfera y los Océanos, Facultad (e.g. Liberato et al. 2011; 2012; 2014). offer a valid alternative to ground based de Ciencias Exactas y Naturales, Historical high-impact winter Nevertheless a consistent catalogue observations but are subjected to some Universidad de Buenos Aires – Consejo storms in Portugal: consistent of historical high-impact winter storms limitations that depend on the type of Nacional de Investigaciones Científicas y catalogues and dependency on for Portugal is still missing. Here the precipitation, topography and type of the Técnicas CONICET, Buenos Aires, objective algorithm, which identifies background surface (Ebert et al. 2007) reanalyses Argentina), M E Zitto (Facultad de and follows individual lows, is applied thus, an evaluation of these products is Ingeniería, Universidad de Buenos Aires, Author Margarida L. R. Liberato to 6-hourly geopotential data at 1000- strongly needed before to use them in Buenos Aires, Argentina), R Piotrkowski Affiliation Universidade de Trás-os- hPa from the ensemble members of the applications. (Facultad de Ingeniería, Universidad de Montes e Alto Douro Twentieth Century Reanalysis (20CRv2) Buenos Aires, Buenos Aires, Argentina. Classical validation of satellite and and to ERA-Interim Reanalysis datasets Co-authors Escuela de Ciencia y Tecnología, reanalysis products still relies on the for the Euro-Atlantic sector and resulting Margarida L. R. Liberato ((1) Instituto Universidad Nacional de San Martín, San use ground networks of rain gauges cyclones datasets are compared. Dom Luiz, Faculdade de Ciências, Martín, Prov. de Buenos Aires, hence the problem of investigating the Universidade de Lisboa, 1749-016 Additionally both reanalysis allow the Argentina),P. Canziani (Unidad de satellite and reanalysis performances in Lisboa, Portugal and (2) Escola de assessment of the synoptic evolution, Investigación y Desarrollo de las data-scarce regions in not eliminated. Ciências e Tecnologia, Universidade de dynamical characteristics and the Ingenierías, Facultad Regional Buenos Given three collocated datasets (a triplet) Trás-os-Montes e Alto Douro, UTAD, Vila main impacts of the top-20 storms Aires, Universidad Tecnológica Nacional, of precipitation, Triple Collocation (TC) Real, Portugal. [email protected]) that provoked extreme impacts and Consejo Nacional de Investigaciones offers a valid alternative to characterize considerable economical losses over Científicas y Técnicas CONICET, Buenos rainfall product errors without relying on Extra-tropical cyclones dominate Portugal. Acknowledgements: This Aires, Argentina) ground-based observations, but TC is autumn and winter weather over western work is supported by FCT – project UID/ subject to several assumptions such as Europe and particularly over the Iberian GEO/50019/2013 – Instituto Dom Luiz. With the aim of understanding climate the existence of an uncorrelated error Peninsula. Intense, high-impact storms processes while managing large between the products of the triplet – a are one of the major weather risks in the datasets and model outputs for climate requirement that is hardly satisfied within mid-latitudes. High winds and extreme variability and change studies, it is often global non-gauge based precipitation precipitation from extra-tropical cyclones convenient to define climate indices. estimates. can result in windstorm damage, flooding These are based on physical principles and coastal storm surges, having large socio-economic impacts.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 107 Section 4 and statistical methods and they can and SAMERA20M respectively) with the Since the beginning of the 20th century, warming of the mid-twentieth century, be derived from observations or from aim to perform a comparison with the the rise of global surface temperature the subsequent cooling and modern reanalysis products. observational index. according to instrumental observations warming. was not monotonous and was One climate index of special interest at A SAM index derived with other It is revealed that temperature changes characterized by two global warming Southern Hemisphere is the Southern methodology (EOF) was also taken into for the current warming period are periods – warming of the mid-20th Annular Mode (SAM), the principal account (AAO 0). All these indices were generally in a good agreement between 2 century and modern warming, separated mode of variability of the atmospheric analyzed and compared on a range of all reanalyses and compare well with by a period of global temperatures circulation in the SH extratropics. This timescales by spatial patterns analysis, empirical data, whereas for the preceding decline. Different reanalysis datasets index has been derived from different correlation analysis, wavelet transform periods, significant differences in the – global gridded data on atmospheric reanalysis, but it was affected by bias and wavelet coherence. The period spatial structure of climatic trends and characteristics obtained with the of pressure values at high southern considered was 1905-2005. We found a their magnitude are found in different atmospheric models with assimilation of latitudes. Due to these reasons, SAM good agreement among all indices and a regions of the Northern Hemisphere, various empirical data – are increasingly index derived by Marshall (based see-saw pattern adequately captured by being most pronounced at high latitudes. used for the analysis of the climate on appropriately located station both reanalyses after 1957. Before 1957, a change. In particular, the temperature evolution in observations) is considered in many weaker see-saw pattern was reflected at NOAA-CIRES 20th Century Reanalysis climate studies, but it is only available both reanalyses, slight better represented Reanalyses are usually available from represents almost a monotonical since 1957. In order to understand how with 20CR. The results provide valuable the second half of the 20th century. But increase in the course of the entire 20th decadal to interdecadal hemispheric information for climate studies linked to in the last decade there have appeared century, whereas ECMWF ERA 20C and regional processes have evolved middle and high latitudes of the Southern reanalyses, covering the entire 20th and CERA 20C reanalyses capture the over time, long time climate indices are Hemisphere. century. Due to the significantly lower two climatic warming periods with a needed, but the limitations originated quantity and quality of observational cooling in between, but overestimate and by the lack of data in the first part of data in the first half of the 20th century, underestimate the magnitudes on the 20th Century must be taken into account. How reliable three 20th century the ability of reanalyses to reproduce early 20th century warming, respectively, ​​ 20th Century Reanalysis (NOAA-CIRES) reanalyses in representing the mid-century warming requires in comparison to the observational data. and ERA 20 C (ECMWF) provide datasets surface air temperature quantitative assessment. spanning the entire twentieth century. evolution in the early 20th Here we analyze evolution of the In this work, these datasets were century period? surface air temperature (SAT) in the considered in order to construct Author Daria Bokuchava Northern Hemisphere according to three “Historical” SAM indices using sea reanalyses covering the entire 20th Institute of Geography level pressure (SLP) values of 20CR Affiliation century: NOAA-CIRES 20th Century Russian Academy of (SAM20) and ERA20C (SAMERA20) Reanalysis and ECMWF ERA20C and Sciences according to Gong and Wang definition CERA20C and compare them to GISS/ (normalized differences of SLP between Co-authors NASA GISTEMP grid dataset based 45°S and 60°S). Likewise, other indices D.D.Bokuchava (Institute of Geography on station observations. The spatial were constructed, only considering the RAS) V.A.Semenov (A.M. Obukhov structure of temperature variation for grid points in the vicinity of the surface Institute of Atmospheric Physics RAS), three climatic periods was analyzed – the stations used by Marshall (SAM20M (Institute of Geography RAS)

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 108 Section 4

ERA-Interim, NCEP-R2, MERRA-2, The relationship between springtime mid- How well the CMIP5 simulations Impact of uncertainties from 7 CFSR/CFSv2, JRA-55 and CGRF. The latitude cyclones and background ozone can reproduce rainfallpatterns atmospheric reanalysis surface pan-Arctic configuration is based on at two rural monitoring sites on the west over Central Africa? conditions on Arctic Ocean the latest version 3.6 of the NEMO coast of Europe – Mace Head, Ireland freshwater budget platform at 1/4° resolution and 75 z-levels. and Monte Velho, Portugal – is explored Author Denis Sonkoué A first assessment of the impact of using a combination of observations and Affiliation University of Yaounde 1 Author Clement Bricaud atmospheric forcing uncertainties on the three reanalyses: 1) the European Centre Co-authors Affiliation Mercator Ocean simulated sea ice extent and thickness, for Medium-Range Weather Forecasts’ on the surface temperature and on the (ECMWF) ERA-Interim reanalysis, 2) the Derbetini Appolinaire Vondou, Co-authors temperature and salinity of water masses Monitoring Atmospheric Composition (University of Yaounde 1) C Bricaud (Mercator Océan), is performed. These assessments are and Climate (MACC) reanalysis and O Hernandez (Mercator Océan), G Garric In this study, we have investigated spatial made with in situ measurements available 3) NASA’s Modern-Era Retrospective (Mercator Océan), J Chanut (Mercator and temporal distribution of rain-fall on the period. Atmospheric sources Analysis for Research and Applications Océan), G Ruggiero (Mercator Océan), over Central Africa (CA) Region (5-35° E, uncertainties of the Arctic FW budget is Version-2 (MERRA-2) reanalysis. CE Testut (Mercator Océan) 15° S-15° N). We used historical simu- finally given in terms of FW storage and The ERA-Interim cyclone tracks are lations of this period 1980–2005 from The Arctic freshwater (FW) has been of solid and liquid FW transports through used here to establish the long-term the Coupled Model Inter-comparison the focus of many modeling studies, Arctic gateways. relationship between cyclones and ozone Projectphase five (CMIP5). We made a due to the potential impact of Arctic observations (since 1988). comparison between 34 CMIP5 and 6 FW on the deep water formation in the The MACC reanalysis data set, which observationaldatasets. Influence of mid-latitude North Atlantic. Similarly, previous and covers the period 2003–2012, is numerous studies have already shown cyclones on European Base on Taylor diagram and Willmott’s background surface ozone produced with the ECMWF integrated refined index of agreement, the se- that atmospheric forcing fields essentially forecast system (IFS) model two-way lection of high performing models is drive the results of Arctic sea ice investigated in observations and coupled to a chemistry transport model made. We realized that, many CMIP5 simulations or are at least as important multiple reanalyses (CTM). Since the MACC reanalysis uses modelsoverestimated/underestimated as the details of the sea ice model itself. a similar atmospheric model to ERA- Given the relative errors found in state Author Katherine Emma the rainfall intensity over CA by up to 8 Knowland Interim, MACC is used to explore the mm.day−1. We also found that a good of the art atmospheric reanalysis in the mechanisms within case study cyclones Affiliation Universities Space reproduction of annual cycle and spatial Arctic Ocean (Lindsay, et al., 2014), we that can influence surface ozone Research Association features of obser-vations depend on the propose here to estimate error bars of concentrations at Mace Head and Monte (USRA) choice of climatic subregion and season the last decade Arctic FW budget related Velho. for models’ skill. to uncertainties errors in state-of-the-art Co-authors atmospheric forcing. KE Knowland (USRA/GESTAR; NASA/ The MERRA-2 reanalysis also provides It is reported that, for assessing future Global Modeling and Assimilation Office 3D distributions of ozone, although change in rainfall or impact studies, MPI- To address this question, we have built less ideal for analysis of surface ozone an ensemble of pan-Arctic experiments (GMAO)), RM Doherty (School of ESM-MR can be used in the northern Geosciences, University of Edinburgh, concentrations since MERRA-2 ozone part of CA, CMCC-CMS in the Equatorial driven at the surface by all the following under represents ozone variability in the global atmospheric reanalysis available Edinburgh, UK), KI Hodges (Department CA andEC-EARTH in the southern part of Meteorology, University of Reading, lower troposphere as MERRA-2 has a of CA. on the 2007-2015 periods: IFS (Integrated Forecasting System from ECMWF), Reading, UK), LE Ott (NASA/GMAO)

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 109 Section 4 less detailed chemistry and emissions Based on quality controlled (RAW) and from four reanalysis is high and JRA-55 Precipitation Analysis (TMPA 3B42RT) in scheme for the troposphere compared to homogenized (ADJ) radiosonde data were relative similar with radiosonde the period 2007-2012. We found that that the MACC reanalysis. from 118 stations in China and monthly with dryer humidity than other three ERA-Interim dataset performs relatively mean specific humidity and relative reanalysis. well in the Northern Hemisphere while However, the MERRA-2 reanalysis has humidity from four reanalysis datasets have some limitations in Africa and South the potential to identify more features The correlation and standard deviation (REA) which included ERA-Interim, America. within the cyclones as the resolution is ratio of specific humidity and relative JRA55, MERRA and CFSR, a preliminary higher than the MACC reanalysis, and humidity demonstrated the higher Satellite based products perform comparison of upper air specific humidity therefore is used in conjunction with the consistence of annual variability and reasonably well within tropical forests and relative humidity over China between MACC reanalysis to provide a measure of dispersion in the lower troposphere and Eastern Asia and North America radiosonde and the third generation uncertainty to the case study analysis. between REA and ADJ, and the but are subjected to errors at northern reanalysis was undertaken. dispersion of REA were obviously higher latitudes. SM2RAINasc performs better We found the main source of high The relative difference, correlation, than ADJ in the middle and upper in the Southern Hemisphere in areas ozone to these two sites is from the standard deviation and linear trend troposphere. where neither ERA-Interim nor the stratosphere, which is well represented during 1979–2015 derived by RAW, ADJ satellite-based datasets provide good in both the MERRA-2 reanalysis and The linear trends of specific humidity are and REA were analyzed. results. the MACC reanalysis, and occurs either consistent between REA and ADJ with from direct injection into the cyclone The results revealed significant wetting trends in the lower troposphere or associated with aged airstreams discontinuities in the raw radiosonde while different in the middle troposphere Intercomparison of Gridded from decaying cyclones that becomes specific humidity and relative with wetting trends from ADJ and drying Observation Data Sets over entrained and descends towards the humidity time series in China and the trends from REA. The linear trends of Turkey surface within new cyclones over the homogenization of original data is relative humidity in the troposphere were region. essential for reanalysis assessment. obviously different between REA and Author Baris Onol Homogenization adjusted the RAW with ADJ with drying trends from REA while Affiliation Istanbul Technical a substantial correction before 2000s. wetting trends and more significant University Inter-comparison of upper air The average specific humidity and wetting in the middle and upper Co-authors water vapor over China between relative humidity over China from REA troposphere. The spatial distribution Baris Onol (Istanbul Technical University), Radiosonde and the third were generally wetter than those from of trends from ADJ at 118 stations and Ceyhun Ozcan (Istanbul Technical radiosonde and the differences of relative REA at the corresponding grids showed generation Reanalysis Datasets University), Baris Kelebek (Istanbul humidity were higher than specific remarkable difference over China. Technical University) Author Zhang Siqi humidity. In this contest, SM2RAIN offers an Affiliation national climat center Meanwhile the differences in the upper additional non-gauge based dataset for The purpose of this study is to analyze all Co-authors troposphere were larger than those in the properly applying TC on a global scale In gridded data sets available over Turkey Zhang siqi (National Climate Center, lower troposphere, and the differences this study, TC analysis has been applied and to reveal differences among them. Beijing 100081, China) Guo yanjun between REA and ADJ were more to the rainfall estimates derived from 1) Temporal and spatial differences of (National Climate Center, Beijing 100081, remarkable than the difference between ERA-Interim, 2) SM2RAIN via inversion gridded data sets have been analyzed for China),Wang guofu (National Climate REA and RAW. The differences in spring of Advanced SCATterometer (ASCAT), temperature and precipitation. Center, Beijing 100081, China) and autumn were more significant than SM2RAINasc, 3) the NOAA Climate those in summer. The consistency of Prediction Center morphing (CMORPH) specific humidity and relative humidity and 4) the TRMM Multi-satellite

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 110 Section 4

These data sets based on observations biases than UDEL for the temperature intercomparison in the Mediterranean are the most commonly used data comparison based on the stations. In Sea, also considering global ocean Intercomparison of Upper Air for regional climate studies. Climate addition, seasonality is more apparent in reanalyses, will take place in 2017-2018. Temperature over China Research Unit (CRU), University of precipitation analysis. The comparison In this context, we show preliminary between Radiosonde and Daleware (UDEL), ENSEMBLES gridded based on the stations for GPCC and results of the evaluation of the Multiple Reanalysis Datasets data (E-OBS) and Global Historical APHRODITE presents better spatial functioning of the Mediterranean Sea Climatology Network/Climate Anomaly coverage over Turkey. However CRU and Author Yanjun GUO (water masses properties, transports Monitoring System (GHCN/CAMS) UDEL precipitation data indicate large through the Strait of Gibraltar, oceanic Affiliation National Climate Center/ data sets are used for temperature biases especially for the extreme values. deep convection) for both global China Meteorogical comparison and CRU, UDEL, E-OBS, The E-OBS precipitation data set is the (GLORYS, Ferry et al. 2012) and regional Administration Global Precipitation Climatology Center most inconsistent data set with the station (MEDRYS, Hamon et al. 2016) reanalyses. Co-authors (GPCC) and Asian Precipitation Highly observations since the number of the Global products have a too high water Yanjun Guo (National Climate Center Resolved Observational Data Integration station used by E-OBS over Turkey is the transports through the Strait of Gibraltar NCC, China Meteorological Toward Evaluation of Water Resources lowest compare to the other data sets. (both in free runs and in assimilated runs), Administration CMA), Siqi ZHANG (APHRODITE) data sets are used for leading to a negative net salt transport (NCC, CMA), Jinghui YAN (NCC, CMA), precipitation comparison. Intercomparison of regional and for the Mediterranean Sea in long-term Zhe CHEN ( National Meteorological In addition, temperature and precipitation global oceanic reanalyses in the average (opposite to what is observed), Information Center NMIC, CMA), biases of ERA-Interim Reanalysis dataset Mediterranean Sea and also to an important decrease of the and Xin RUAN (NMIC,CMA) have been calculated by using all the salinity of the surface layer (0-150m). The observational data sets after regridding Author Jonathan Beuvier intermediate layer (150-600m) is too high Based on quality controlled (RAW) and homogenized (ADJ) radiosonde same spatial resolution (approximately Affiliation Mercator Océan and too fresh in the free runs. Moreover, 80 km) over Turkey for the period of the deep layers (below 600m) display an temperatures at 10 pressure levels from Co-authors 1981-2010. The gridded data sets has unrealistic interannual variability, both 118 stations across China, and monthly J. Beuvier (Mercator Océan/Météo- been analyzed and the differences of in temperature and salinity, before year mean temperatures from 8 reanalysis France), M. Hamon (Mercator Océan), precipitation and temperature data sets 2005 and the substantial deployment of datasets (REA) including NCEP-1, C. Desportes (Mercator Océan), are highlighted over the coastal and the the Argo network in the Mediterranean. NCEP-2, ERA-40, ERA-Interim, JRA-55, M. Drévillon (Mercator Océan), high elevation regions. We have also For the deep convection, a focus is 20CR, MERRA and CFSR, a preliminary J.-M. Lellouche (Mercator Océan), compared all the data sets by using the made on winter 2013 in the Gulf of Lion, comparison of upper air temperature Y. Drillet (Mercator Océan) 187 meteorological station over Turkey. to benefit from the oceanic Special over China between radiosonde and reanalysis data was undertaken. For this analysis, the station values One of the objectives of the COST action Observation Period of the HyMeX compared with the corresponding grid “Evaluation of Ocean Syntheses” (see program (Estournel et al. 2016). The mean difference, correlation, points (nearest point) from the each of presentation by Alvera-Azcárate et al.) standard deviation and linear trend of the data set. is to foster regional ocean reanalyses upper air temperature based on original It is revealed that the mean temperature intercomparisons, which focus on the and homogenized radiosonde and for all the gridded data sets are lower evaluation of specific regional processes reanalysis temperature during 1981–2010 than the station observations. Despite and variability, in particular in ocean were analyzed. Generally, homogenized the seasonal differences, GHCN/CAMS, and climate variability “choke points” temperatures averaged over China were CRU and E-OBS indicate generally lower such as the Mediterranean Sea. An cooler than RAW, and the negative

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 111 Section 4 adjustment in the upper troposphere and few implausible circulation trend patterns This comparison can give us the clue lower stratosphere was more significant Interdecadal variation of are found in the GW mode, such as which reanalysis is better for studying than in other layers. atmospheric overturning strong increases in the tropospheric different phenomena (QBO, NAO, ENSO, temperature over the Antarctic, and etc.) and which one has some issues. Homogenization removed system error circulation in the ERA-20C decreases in atmospheric humidity in caused by radiosonde instrument change reanalysis the northern extratropics. The causes of and updates to the radiation adjustment Author Bo Dong these spurious changes in the ERA-20C Monitoring and long-term method and observation system of RAW. Affiliation University of Reading reanalysis deserve further investigation. assessment of the Hence, the correlation between REA and Mediterranean Sea physical ADJ was higher than that between REA Co-authors and RAW. The mean difference between Bo Dong Long-term trends in the state REA and ADJ was approximately 1°C Author Simona Simoncelli The phase transition of the Interdecadal stratosphere using reanalyses during 1981–2010, while REA was mostly Istituto Nazionale di Pacific Oscillation (IPO) is one possible Author Michal Kozubek Affiliation cooler than ADJ in the troposphere and Geofisica e Vulcanologia warmer in the stratosphere. Significant cause of the early 2000 global warming Affiliation Institute of atmospheric correlation demonstrated the consistency hiatus. To physically understand the physic Co-authors modulation, changes in atmospheric Simona Simoncelli (INGV), Claudia between the annual variability of REA Co-authors and ADJ. overturning circulations and the Fratianni (INGV), Emanuela Clementi associated energy transport for the IPO Michal Kozubek (IAP) (INGV), Massimiliano Drudi (INGV), The linear trends were consistent and global warming (GW) are quantified The long-term trend of different Jenny Pistoia (INGV), Alessandro Grandi between REA and ADJ, with warming and contrasted using the ERA-20C atmospheric parameters has been (INGV), Damiano Del Rosso (INGV), in the lower and middle troposphere reanalysis data. studied separately during previous Andrea Storto (CMCC) and cooling in the middle stratosphere. years in many papers. This study is Greater uncertainty was apparent Multiple linear regression analyses The near real time monitoring and long- focused on the temperature, wind (u and for the upper troposphere and lower show that both warm IPO and GW term assessment of the physical state v component), geopotential height and stratosphere. ERA-Interim, JRA55 modes feature significant weakening of the ocean are crucial for the wide watervapour trends during 1979-2016. and MERRA were generally closer to and eastward shift of the Pacific CMEMS user community providing a We present the trend for each month with homogenized radiosonde temperatures Walker circulation, and strengthening continuous and up to date overview respect to ozone turnaround during mid than the other reanalysis datasets. of the Hadley circulation, characterized of key indicators computed from by southward shift of the ITCZ and 1990s. operational analysis and reanalysis intensified deep tropical convection The different reanalyses (MERRA, datasets. with contracted meridional extent. Also, ERA-Interim, JRA-55 and NCEP-NOE) strengthening in the subtropical jet, This constitutes an operational warning are used for comparison. We analyzed system for the advanced prediction of increases in tropospheric temperature every grid point to reduce the problem and humidity are found. extreme events, stimulating the research with zonal averages indifferent pressure towards a deeper understanding of them The resemblance of the two trend modes levels. The results will show the and consequently increasing CMEMS indicates that circulation anomalies complex view on the trend in the middle products uptake. Ocean Monitoring of warm (cold) IPO phases amplify atmosphere (troposphere, stratosphere Indicators (OMIs) of some Essential (dampen) the anthropogenic warming- and lower mesosphere). Ocean Variables have been identified induced circulation trends. Besides, a and developed by the Mediterranean

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 112 Section 4

Monitoring and Forecasting Centre the mid-latitudes and in the sub-polar (MED-MFC) under the umbrella of the Multidecadal Rainfall Variability region as well as in eastern North New framework for comparative CMEMS MYPWG (Multy Year Products in Sahel Atlantic with values around R = 0.8. assessment of surface fluxes Working Group). Similarly, ERA20C reanalysis dataset from reanalyses and satellites Author Ellen Berntell exhibits multidecadal rainfall variability in These OMIs have been operationally Affiliation Department of Sahel with a dominating period of 60- Author Sergey Gulev implemented starting from the physical Meteorology, Stockholm 80 years, however largely out of phase Affiliation IORAS reanalysis products and then they have University with the observational dataset and with been applied to the operational analyses. Co-authors no correlation to the North Atlantic sea Sea surface temperature, salinity, height Co-authors Sergey K. Gulev (IORAS), Natalia Tilinina surface temperatures. as well as heat, water and momentum E Berntell (Stockholm University) (IORAS) and Konstantin Belyaev (IORAS) fluxes at the air-sea interface have been The composite analysis of low-pass The Sahel is a water vulnerable region Surface turbulent heat fluxes from operationally implemented since the filtered data showed a clear increase of which exhibits strong inter-annual rainfall modern era and first generation reanalysis system development as a real rainfall across Sahel in wet compared to variability. During the 20th century the reanalyses (NCEP-DOE, ERA-Interim, time monitoring of the data production. dry years for both the CRU observational Sahel region experienced extended dry MERRA NCEP-CFSR, JRA-25/55) as well and ERA20C reanalysis datasets. The Their consistency analysis against periods and droughts, with devastating as from satellite products (SEAFLUX, composite difference for the sea level available observational products or effects on the livelihoods of the people in IFREMER, HOAPS) were intercompared pressure and surface temperature budget values recognized in literature the region. In this study the multidecadal using probability distributions for sensible suggest that a strengthening of the guarantees the high quality of the variability of Sahel precipitation is and latent heat fluxes. thermally driven meridional pressure numerical dataset. The results of examined in the gridded observational gradient between Sahara and the Coast For approximation of probability the reanalysis validation procedures dataset CRU and in the 20th-century of Guinea in wet compared to dry distributions and estimation of extreme are yearly published in the QUality reanalysis ERA20C. years is the driving mechanism for the flux values Modified Fisher-Tippett (MFT) Information Document since 2014 Additionally, we use the Hadley sea multidecadal rainfall variability in Sahel distribution has been used. Besides available through the CMEMS catalogue surface temperature and sea level for both the observational and reanalysis mean flux values, consideration is (http://marine.copernicus.eu), together pressure datasets and the coupled dataset. given to the comparative analysis of with the yearly dataset extension. reanalysis CERA20C. Our analysis of (i) parameters of the MFT probability The strengthened gradients both New OMIs of the winter mixed layer the Sahel (10−18N, 20W -30E) July- density functions (scale and location), (ii) increase the moisture in the region depth and the heat content will be September rainfall using CRU shows extreme flux values corresponding high through increased moisture flux and presented, in particular we will analyze a clear multidecadal variability with a order percentiles of fluxes (e.g. 99th and intensifies the monsoon system through their time evolution and trends starting dominating period of 60-80 years and a higher) and (iii) fractional contribution of strengthened monsoon winds, resulting from 1987. Consistency analysis between high correlation to the North Atlantic sea extreme surface flux events in the total in increased rainfall. The study shows OMIs computed from global, regional surface temperatures on a multidecadal surface turbulent fluxes integrated over that it is challenging to capture the reanalysis and analyses datasets will be scale. months and seasons. multidecadal Sahel rainfall variability in shown as well. At the end, the focus will Using a global field correlation and a reanalysis data. Reasons for this behavior The latter was estimated using both be on 2016 sea state and circulation of single value decomposition we could are discussed and the behaviour of the fractional distribution derived from the Mediterranean Sea and its anomaly see that the highest correlation between Sahel precipitation is also analyzed for MFT and empirical estimates based with respect to the climatological fields to low-pass filtered Sahel rainfall and sea CERA20C. upon occurrence histograms. The detect the 2016 peculiarities. surface temperatures was located in strongest differences in the parameters

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 113 Section 4 of probability distributions of surface long record of low-frequency climate In the context of the EU-funded ERA- 20C surface fields, which in return fluxes and extreme surface flux values variability using a consistent set of CLIM2 project, ECMWF produced a ten- result from changes in the atmospheric between different reanalyses are found in observations. member ensemble of 20th century Ocean observing system. the western boundary current extension ReAnalyses called ORA-20C. ORA-20C To account for errors in the observational The influence of the temperature regions and in high latitudes, while the assimilates temperature and salinity record as well as model error, CERA- assimilation increments on the heat highest differences in the fractional profiles and is forced by the ECMWF 20C provides a 10-member ensemble budget is growing with time. Increments contributions of surface fluxes may 20th century atmospheric reanalysis of reanalyses. Regarding observation control the most recent ocean heat occur in mid ocean regions being closely (ERA-20C) over the 1900-2010 period. data, surface pressure and marine uptake signals, highlighting imbalances in associated with atmospheric synoptic This study attempts to identify robust wind observations as well as ocean forced reanalysis systems as well in the dynamics. Generally, satellite surface flux signals of ocean heat content change in temperature and salinity profiles are ocean as in the atmosphere. products demonstrate relatively stronger ORA-20C and detect contamination by assimilated in the CERA-20C assimilation extreme fluxes compared to reanalyses, model errors, initial condition uncertainty, system. even in the Northern Hemisphere surface fluxes and observing system On the selection of suitable midlatitudes where data assimilation input These observation data, as well as changes. predictors from NCEP/NCAR in reanalyses is quite dense compared to model departures before and after It is shown that ORA-20C trends and reanalysis datasets over the the Southern Ocean regions. assimilation and usage flags, are stored variability in the first part of the century in observation feedback archive files. Western Himalayas result from the surface fluxes and model These files can be used to improve our drift towards warmer mean state and Author Jitendra Kumar Meher Observation feedback understanding of the climate as they weak meridional overturning circulation. Affiliation Bidhan Chandra Krishi information of the ECMWF confront observations with model in a The impact of the observing system in Viswavidyalaya coupled climate reanalysis consistent and systematic way. correcting the mean state causes the Co-authors Author Yuki Kosaka This presentation will describe deceleration of the warming trend and Jitendra Kumar Meher (Department of Affiliation JMA/ECMWF assessment results of CERA-20C such alters the long-term climate signal. The Agricultural Meteorology and as trends of the analysis field and quality ensemble spread reflects the long-lasting Co-authors Physics,Bidhan Chandra Krishi of the observations. memory of the initial conditions and the Yuki Kosaka (JMA/ECMWF), Patrick Viswavidyalaya, Mohanpur-741252, convergence of the system to a solution Laloyaux (ECMWF), Eric de Boisseson Nadia, West Bengal, India), Lalu Das compatible with surface fluxes, ocean (ECMWF), Per Dahlgren (ECMWF), (Department of Agricultural Meteorology Ocean heat content variability model and observational constraint. Dinand Schepers (ECMWF) and Physics, Bidhan Chandra Krishi in an ensemble of 20th century Viswavidyalaya, Mohanpur-741252, ocean reanalyses Observations constrain the ocean heat The European Centre for Medium- uptake trend of the last decades of Nadia, West Bengal, India), Rasmus E. Range Weather Forecasts (ECMWF) Author Eric de Boisseson the 20th century, which is similar to Benestad (The Norwegian Meteorological has developed a coupled assimilation institute, PO Box 43 Blindern, NO-0313 Affiliation ECMWF estimations from the post-satellite era. system that ingests simultaneously An ocean heat budget analysis attributes Oslo, Norway), Abdelkader Mezghani Co-authors ocean and atmospheric observations in ORA-20C heat content changes to (The Norwegian Meteorological institute, E de Boisseson (ECMWF), M. Balmaeda a coupled ocean-atmospheric model. surface fluxes in the first part of the PO Box 43 Blindern, NO-0313 Oslo, (ECMWF) and M. Mayer (University of This approach has been used to produce century. The heat flux variability reflects Norway) Vienna/ECMWF) a new coupled 20th-century reanalysis, spurious signals stemming from ERA- called CERA-20C, which provides a

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 114 Section 4

Present study provides a proper in different domains showed that, Simulation experiments spanning eight University planetary boundary layer guideline for selecting suitable predictors geopotential height at 850 hPa, relative (8) months (from April to November) was schemes is not suitable for seasonal from NCEP/NCAR reanalysis datasets humidity at 500 & 1000 hPa, divergence performed for two different years, a dry precipitation forecast over Ghana due to in simulating observed annual and at 500 hPa and sea level pressure were (2001) and a wet (2008) using the ERA- their abysmal performance. seasonal rainfall of Western Himalayan independent of the method and season Interim reanalysis data as the large-scale Region (WHR) through considering of predictor selection as their ranks have forcing data. A double nested approach three different sizes of domains namely less standard deviation than the other was used with the outer domain at Performance evaluation of Western Himalayas, India and South predictors. 50 km resolution covering the whole CMIP5‘s characterisation of Asia. Multi-types statistical measures of West Africa and the inner domain circulation over Southern Africa like spatial and temporal correlations, covering Ghana (the study area) at 10 km Optimal physics and its adjacent oceans using stepwise regression coefficients (R2) resolution. reanalyses. were used to evaluate the skills of the parameterization scheme The WRF scheme combinations predictors. combination of the Weather Author Teboho Nchaba overestimated generally the observed University of Cape Town It is found that, predictors have shown Research and Forecasting (WRF) precipitation data up to a mean value Affiliation stronger positive or negative spatial model for seasonal precipitation between 3% – 64% for both dry and Co-authors correlations in annual and monsoon forecast over Ghana. wet years across the country. Most TD Nchaba (Climate System Analysis season compared to winter season. In scheme combinations overestimated Group, University of Cape Town),C Author Richard Agyeman all the selected domain, the mean of the (underestimated) the observed data over Lennard (Climate System Analysis Group, R2 values obtained for all the predictors Affiliation Ghana Meteorological the Coastal (Northern) zones of Ghana University of Cape Town), were higher during monsoon than annual Agency for both years and near 0% bias over the The third generation reanalyses, the and winter season. Co-authors forest and transitional zones. 1. Richard Yao Agyeman (Ghana CFSR, MERRA-2, and ERA-Interim, It is found that the first EOFs of most However, no single scheme combination Meteorological Agency) are used in this study to evaluate the of the predictors were consistently well was able to simulate best the observed performance of the Coupled Model correlated (RE) with the predictand in To help mitigate against effects of data across all the four agro-ecological Intercomparison Project Phase 5 annual and monsoon time scale over all drought and floods on agriculture, zones for both wet and dry years. On (CMIP5) historical runs in characterizing the selected domain, whereas, in winter hydropower generation, water the whole, combination of WRF Single- atmospheric circulation over Southern season, none of the EOFs shown such management, disaster control etc, Moment 6-class (WSM6) microphysics Africa and its adjacent oceans. The consistent results. In general it is found seasonal to annual predictions are key scheme, Grell-Devenyi (GD) ensemble evaluation is performed for austral that, during the monsoon season the for any effective planning. Towards cumulus parameterization scheme and summers during the satellite era between predictors were having higher RE values a seamless seasonal forecasting for Asymmetric Convective Model (ACM2) 1980 and 2004. Reanalyses show than the winter and annual time scale. Ghana, this work seeks to obtain the best planetary boundary layer scheme decreases in near surface wind speeds, simulated best temporal pattern, at 850 hPa and 10-m above ground level, Predictors like relative humidity at 500 combination of physical parameterization temporal variability with least relative bias over the South East Atlantic and west hPa, specific humidity at 500 hPa, schemes of the Weather Research and for both years across the country. coast of Southern Africa over the study geopotential height at 1000 hPa and Forecasting (WRF) model that can be use period. precipitation rate were well simulated for seasonal precipitation forecast over These scheme combination is therefore by observed precipitation over different Ghana. recommended for seasonal precipitation predictor domains. Sensitivity analysis of forecast over Ghana. On the contrary, ranks obtained by each of the predictors combination of WSM6, GD and Yonsei

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 115 Section 4

These changes in speeds are associated We evaluated the performance of aim at investigating the performance with changes in the intensity of and a objective analysis datasets over the Planetary boundary layer of various hindcasts with respect to poleward migration of the South Atlantic Pacific Arctic Ocean, the Chukuchi and depicted by most recent regional the representation of the planetary Anticyclone, the midlatitude westerlies, Bering Seas based on meteorological reanalyses boundary layer (PBL), i.e. how well the the storm tracks and the descending limb observations during the R/V Mirai Arctic thermo- and hydrodynamic state of the of the Hardly Cell. cruises in the summer of 2013, 2014 and Author Ronny Petrik PBL is captured by the models. Our 2015. Affiliation Helmholtz Centre study involves, on the one side, regional The Southern Annular Mode indices Geesthacht Institute for hindcasts utilizing state-of-the-art/superb extracted from the reanalyses also The radiosonde and marine weather Coastal Research data assimilation to force the model to show an inclination towards their observations captured detailed time observations. Thanks to the UERRA positive polarity, indicative of antarctic variations and vertical structures Co-authors project most recently reanalyses were ozone depletion and Green House of temperature, wind and humidity Petrik (Helmholtz-Zentrum Geesthacht, performed over Europe and provided Gases induced warming of sea surface associated with the Beaufort High, Institute for Coastal Research) , Beate by various European meteorological temperatures. All these kinematic synoptic-scale cyclone, polar low and Geyer (Helmholtz-Zentrum Geesthacht, services (for instance the COSMO- properties of circulation elements seasonal change. Institute for Coastal Research), Burkhardt REA6 product by the DWD). On the observed in the reanalyses are used Rockel (Helmholtz-Zentrum Geesthacht, While 4 atmospheric reanalyses (ERA- other side, our study involves regional as a benchmark to evaluate the CMIP5 Institute for Coastal Research) Interim, CFSv2, MERRA, JRA-25) and hindcasts based on downscaling global models’ performance in reproducing initial values of the forecast from 8 “Within the framework of the project reanalyses (as done for example at the them. Evaluating the performance of weather centers around the world from openFRED feed in power within complex Helmholz-Zentrum in Geesthacht).In the the historical runs of the CMIP5 models the TIGGE (THORPEX Interactive Grand electricity grids are simulated with energy presentation we address the problem of allows for models’ selection and provides Global Ensemble), roughly reproduced system models over a couple of years. finding evaluation data independent in a baseline for analysing their projections. the above characteristics, there were The energy system models require to the sense of a data assimilation process. some differences. have input data for the energy production The evaluation of the daily cycle of the of each single renewable power plant. PBL is shown as well as the performance Performance of objective Compared to the observation, the large One of the possibilities is to rely on the with respect to the timing of specific analysis data over the Pacific differences were seen in the temperature data from regional hindcasts, because lower-tropospheric weather events. Arctic Ocean in summer based near the boundary layer and tropopause, they allow to get a detailed picture of Moreover, it is discussed whether and wind speed in the whole troposphere and on meteorological observations the atmospheric processes during the how far the reanalysis products are water vapor in the lower troposphere. during the R/V “Mirai” Arctic last decades. This details can still not superior over the “simple” downscaling cruises The spread among the datasets were be provided by the global reanalysis products.” also large for those variables. It is products as ERA, NCEP or MERRA. Author Kazuhiro Oshima likely that the discrepancies are due However, the main question arises how Affiliation Japan Agency for to different treatments of snow/ice suitable are the regional hindcasts for Marine-Earth Science processes and of vertical resolution the application with energy system and Technology among the models using for the datasets. modelling. Co-authors Our main focus is on the simulation K. Oshima (JAMSTEC), M. E. Hori of feedin power with respect to solar (JAMSTEC), Y. Kawai (JAMSTEC), plants, wind turbines and hydroelectric K. Sato (NIPR), J. Inoue (NIPR) power stations. As a first step, we

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 116 Section 4

for instance shows that, The low Bering Strait and the Barents Sea Precipitation over monsoon Asia: Reanalysis Wind field validation resolution (0.5 degrees) model, cannot Opening) have become available through a comparison of reanalyses and over Egypt capture the true behaviour of the wind the ARCGATE project (“Maximizing the observations field down to station scale. potential of the Arctic Ocean Gateway Author Ahmed Shalaby array”). Author Andrea Toreti Affiliation Egyptian Meteorological The ARCGATE estimates (currently Affiliation European Commission, Authority Reanalysis-based volume-, available October 2004 to May 2010) are Joint Research Centre Co-authors temperature- and freshwater transports through arctic derived from mooring data in the four Co-authors Z Salah (Egyptian Meteorological straits under the constraint of mass-, A. Toreti (European Commission Joint Authority), A Shalaby (Egyptian gateways vs. mooring-derived and salinity conservation and include Research Centre), A. Ceglar (European Meteorological Authority), A Sidhom estimates realistic assumptions about freshwater Commission Joint Research Centre), (Egyptian Meteorological Authority) Author Sebastian Stichelberger input. We compare these new and G. Balsamo (European Centre for Reanalyis data is considered a necessary largely independent flux estimates (i.e. Medium-Range Weather Forecasts), Affiliation University of Vienna dataset to analysis the 3D dynamics most ARCGATE observations have not S. Kobayashi (Japan Meteorological Co-authors of the atmosphere. In addition, the been assimilated in the reanalysis) to Agency) S. Stichelberger (University of Vienna, Reanalsysis data provides the lateral data of the Centro Euro-Mediterraneo Department of Meteorology and boundary conditions for regional climate sui Cambiamenti Climatici Global Reanalyses represent an essential source Geophysics, Vienna, Austria ), model and as initial condition for regional Ocean Reanalysis System “C-GLORS, of information for impact modelling M. Pietschnig (University of Vienna, weather forecast models. Nevertheless, Version 5” and the latest ECMWF and monitoring in areas of the world Department of Meteorology and the regional validation and station Ocean Reanalysis System “ORAS5”. We characterised by sparse observational Geophysics, Vienna, Austria ), M. Mayer scale validation of the Reanalysis are investigate the differences between the network and/or limited data access. This (University of Vienna, Department of necessary to rely on as a tool to analyze datasets by preparing Hovmoeller plots study focuses on Monsoon Asia, a key Meteorology and Geophysics, Vienna, the true state of the atmosphere. We of volume-, temperature- and freshwater agricultural region of the world. Austria ), T. Tsubouchi (Alfred Wegener have found a severe discrepancies transports. Four reanalyses (ERA-Interim, ERA- Institute, Climate Sciences – Physical between the ERA_Interim and FNL Generally, the patterns agree qualitatively Interim Land, AgMerra and JRA-55) are Oceanography of the Polar Seas, datasets with coastal and inland ground at most locations. An exception are analysed and compared with two gridded Bremerhaven, Germany), A. Storto stations in Egypt. discrepancies in Davis Strait transports observational datasets: Aphrodite and (Centro Euro-Mediterraneo sui at the West Greenland slope region, Chirps. Seasonality, extremes and The reanalysis wind (direction and speed) Cambiamenti Climatici, Ocean Modeling where upper-ocean volume transports distributional differences are assessed by climatologies show more than 75% and Data Assimilation Division, Bologna, are northward in ARCGATE throughout using a combination of recently proposed error. In this work we have validated the Italy ), H. Zuo (ECMWF, Reading, United the year whereas they are northward only statistical methods. The main results reanalysis data with respect to many Kingdom), L. Haimberger (University of during the spring season in C-GLORS show the good performance of the surface stations in Egypt for more than Vienna, Department of Meteorology and and during the spring and summer bias-corrected reanalysis AgMerra, the 30 years. Temperature and mean sea Geophysics, Vienna, Austria ) season in ORAS5. temporal homogeneity of JRA-55 and the level pressure show a good agreement Recently, new estimates of volume-, good spatial representation provided by with surface observation, while Wind Comparing time series of total volume-, temperature and freshwater transports ERA-Interim Land. speed and wind direction suffer from a temperature- and freshwater transports into the Arctic Ocean through the four severe bias. The comparison of regional through each strait from ARCGATE climate simulation forced by ERA_Interim major gateways (Davis-, Fram-, and

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 117 Section 4 against the C-GLORS and ORAS5 data Air pollution has become a serious year 2006. Wind over India and Pakistan A sensitivity assessment performed we find good quantitative agreement challenge for developing countries like is found to be the major meteorological through realistic perturbation of the for both reanalyses only in Fram Strait Pakistan. Very scarce information is parameter that determines the main sources of uncertainty in ocean volume-, and in Bering Strait temperature available regarding pollution levels in this transboundary aerosol transport. reanalyses highlights that bias- transports. geographic region. This study presents correction and pre-processing of in- the first modelling work to simulate situ observations represent the most Considerable disagreement is found for the spatial distribution and temporal Sensitivity of ocean heat crucial component of the reanalysis, the other straits and transport types, variation of aerosol concentrations over content from reanalyses to the whose perturbation accounts for up to which must be investigated further. The Pakistan by using the Weather Research atmospheric reanalysis forcing: 60% of the ocean heat content anomaly net export of volume out of the Arctic and Forecasting Model coupled with variability in the pre-Argo period. Ocean derived from ARCGATE is – 0.15 a comparative study chemistry (WRF-Chem). ± 0.06 Sv. This value is matched by Author Andrea Storto These results reveal useful information ORAS5 very well (- 0.14 ± 0.18 Sv), while Simulated aerosols species include for the ocean observation community Affiliation CMCC C-GLORS net volume export is only sulfate, nitrate, ammonium, organic and for the optimal generation of about one third of the ARCGATE estimate carbon, black carbon, and PM2.5 Co-authors perturbations in ocean ensemble (- 0.05 ± 0.22 Sv). (particles with a diameter of 2.5 μm A Storto (CMCC), C Yang (CNR-ISAC), systems. Additional information on the or less), which are evaluated against S Masina dependence of the quality of ocean ground-based observations and satellite The global ocean heat content evolution reanalyses from atmospheric products Seasonal variations of aerosols measurements. In year 2006, simulated are also presented. in Pakistan: Contributions of is a key component of the Earth’s PM2.5 concentrations averaged over energy budget and can be accurately domestic anthropogenic northeastern Pakistan (71-74.5E, 28- determined by ocean reanalyses that Severe rainstorms over India emissions and transboundary 34N) are 55, 48.5, 31.5, and 98 µg/m³ assimilate hydrographic profiles. This during the summer monsoon transport in January, April, July, and October, work investigates the impact of the respectively. atmospheric reanalysis forcing through a season as seen in NCEP/NCAR Author Muhammad Zeeshaan reanalysis Shahid The simulated highest PM2.5 multi-forcing ensemble ocean reanalysis, concentration in October results from where the ensemble members are forced King Abdullah University Author Jayashree Revadekar Affiliation the relatively low temperatures that favor by five state-of-the-art atmospheric of Science and Affiliation Indian Institute of Tropical nitrate formation as well as the lowest reanalyses during the meteorological Technology, Thuwal Meteorology precipitation that leads to the smallest satellite era (1979-2013). Saudi Arabia Co-authors wet deposition of all aerosol species. The Data assimilation leads the ensemble Co-authors simulated lowest concentration of PM2.5 Hamza Varikoden (Indian Institute of M.Z. Shahid1, H Liao1 (Institute of to converge towards robust ocean heat Tropical Meteorology, Pashan, Pune, in July can be attributed to the largest content estimates and significantly Atmosphere Physics Chinese Academy precipitation associated with the South India) of Sciences, Beijing 100029, China1), reduces the spread (1.48 +/- 0.18 W/m2, Asian summer monsoon. Severe rainstorms over India during J Li2(College of Global Change and Earth per unit area of the World Ocean); hence the summer monsoon season as seen System Science (GCESS), Beijing Normal Sensitivity studies show that the impact of the atmospheric forcing in NCEP/NCAR reanalysis Jayashree University, Beijing 100875, China2), I transboundary transport contributes appears only marginal for the global heat Revadekar and Hamza Varikoden Shahid3 (Institute of Space Technology, to PM2.5 aerosol levels in northeastern content estimates in both upper and Indian Institute of Tropical Meteorology, Islamabad, Pakistan3) Pakistan by 10-20% in January and April deeper oceans. and by 10-40% in July and October of Pashan, [email protected].

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 118 Section 4 inAbstract: During the summer monsoon the spatio-temporal patterns of rainfall the large scale seasonal distributions of comparative analysis was made from months (June through September), during severe storm situations between rainfall observed by different sources are different reanalysis datasets: ECMWF- severe rainstorms or heavy rainspells the observed and reanalysis rainfall. The simulated fairly well by the model. ERA40, ECMWF-ERA20C and NCEP- occur due to the passage of monsoon system formation and its intensification NCAR reanalysis I. However, a closer look at the time series depressions, cyclonic storms and other are well captured by the reanalysis of the simulated rainfall over smaller Anomalies of each PDO phase obtained synoptic systems across the country. but they do not propagate sufficiently regions represented by different boxes with NCEP-NCAR reanalysis I and Slow-moving and stationary cyclonic towards the land areas. over the SAARC region indicate that ERA-40 datasets showed agreement in disturbances also cause exceptionally while the model values are generally the averaged fields. The ERA-20C data heavy rainfall over some regions. Simulation of Seasonal Monsoon underestimated over Afghanistan, indicated lower agreement in the signal Almost every year, the intense rainspells rainfall over the SAARC Region Pakistan and northwestern parts of in relation to the other two analyzed associated with severe rainstorms by Dynamical Downscaling using India, the rainfalls are overestimated in sources. In general, opposite patterns lead to huge losses in terms of life and the central parts of India, Western Ghat of atmospheric circulation over the property. An understanding of the nature WRF Model mountains, Nepal, Bhutan, Bangladesh, Pacific Ocean and South America were of the severe rainstorms is essential Author Md. Mizanur Rahman Sri Lanka and Maldives. identified in the negative and positive for planning precautionary measures, phases of the PDO between 1970 and Affiliation East West University designing hydraulic structures such as 2003. During the negative (positive) dams, spillways etc. Information on the Co-authors South America climate on the phases of the PDO, positive (negative) characteristics of severe rainstorms Md. Mizanur Rahman, East West Pacific decadal oscillation scale anomalies of geopotential height at 250 offers the key to undertaking proper University. Dhaka, Bangladesh through NCEP-NCAR Reanalysis hPa were observed over the southeast of measures for disaster mitigation and Simulation of the seasonal monsoon I and ECMWF-ERA40 South America. Wind anomalies showed damage reduction. rainfall during June-July-August (JJA) opposite signs to those observed in the Author Bruna Simões Lima negative and positive phases of the PDO, Evaluation and exploitation of reanalysis is carried out for 5 year (2006-2010) Affiliation University of Sao Paulo in the central-east of South America. data sets not only helps us to obtain using WRF-ARW model over the SAARC NCEP-NCAR reanalysis I presents a more complete information related to region. The NCEP/FNL analysis data is Co-authors stronger signal than the ERA-40C data atmospheric phenomena, but also helps utilized as initial and lateral boundary Bruna Simões Lima (University of Sao over the central of South America, areas in the planning of advanced versions conditions (LBCs) at six hourly intervals. Paulo), Maria Elisa Siqueira Silva of great wind anomalies in the three PDO of longer and more complex reanalysis The model is run at 50 km horizontal (University of Sao Paulo) phases. Maximum differences in the 250 by providing useful feedback to the resolution and 27 vertical sigma levels. In this study we investigated the climatic hPa geopotential height between the two reanalysis producers. In the present 12 separated boxes are selected patterns of the dry and rainy seasons reanalysis is of the order of 50 mgp. context, an appraisal of capability of representing different geographical of the atmospheric circulation and NCEP/NCAR reanalysis data in simulating characteristics over the 8 countries precipitation over South America during The Antarctic region also present lower the heavy rainspells is very important in (Afghanistan, Pakistan, India, Nepal, the negative and positive phases of high level geopotential height values in studies of regional water resources. Bhutan, Sri Lanka and Maldives) for the Pacific Decadal Oscillation (PDO) the ERA-40 reanalysis. During the PDO negative phase, there is an intensification Therefore, the present study examines studying the monsoon rainfall. Observed between 1970 and 2003. Besides of the trade winds over the northeast the daily rainfall data of NCEP/NCAR rainfall by TRMM, GPCP, and CMAP are to the analysis of the mean climatic of South America, both in high and low reanalysis to bring out the nature of used for verifications of the simulated characteristics of each PDO phase levels, and, the intensification of the some heavy rainspells. Study reveals that rainfall. Results show that in general (1970-1976; 1977-1996; 1997-2003), northerly flow in the central region of the there are some remarkable similarities in in the annual and seasonal scales, a

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 119 Section 4 continent, these processes are more Although the three first EOF modes the low level zonal wind anomaly in the signal likely results from several factors intense during the rainy season (October obtained from the 850 hPa stream northern South America is not observed such as the albedo feedback due to to March) than in the dry season (April to function show very similar spatial in the JRA55 data. a diminishing cryosphere, enhanced September). patterns over South Pacific and South poleward atmospheric and oceanic heat This aspect in the low level zonal wind America in the three considered transport, and changes in humidity. It was possible to verify the dipole anomaly is observed both for positive reanalysis, it is possible to notice pattern in the geopotential height and negative PDO phases, constituting Surface albedo feedback is stating that some important differences among anomalies between the southeast and an important distinction since it is the additional amount of shortwave the original values. At 250 hPa, NCEP- northeast of South America from the two observed throughout the whole analysed radiation at the top of the atmosphere NCAR reanalysis I and ERA40 stream data sources. However, the strongest period. decreases with decreasing surface function 3rd EOF modes agree very well meridional wind anomalies observed albedo whereas surface air temperature while JRA55 presents great differences in the NCEP-NCAR reanalysis I is more increases with decreasing surface in relation to these other two datasets. aligned in the meridional direction if Spring snow albedo feedback in albedo. Unfortunately, there remains a While NCEP-NCAR reanalysis I and compared to the ERA-40 data. daily data over Russia. Analyzing lack of reliable observational data over ERA40 3rd EOF modes show a well in-situ data in comparison with large parts of the cryosphere. Satellite characterized mean wave train pattern, products cover large parts of the NH, based on 250 hPa stream function reanalyses South America climatic impact but have problems with large solar zenith data, over South Pacific and a center during PDO phases based on Author Martin Wegmann angles as well as over complex terrain of action on the southeastern South NCEP-NCAR reanalysis I, JRA55 Affiliation University of Grenoble (eg. Wang et al. 2014). America, JRA55 shows only reversal and ERA40 signs over South Pacific, from tropical Co-authors Our analysis focuses at the Russian M. Wegmann (Institut des Géosciences Author Maria Elisa Siqueira Silva to middle latitudes. Considering the territory where we utilize in-situ radiation original values, NCEP-NCAR reanalysis de l’Environnement, University of and snow depth measurements. We Affiliation Univerty of São Paulo I shows the strongest anomalous signs Grenoble, Grenoble, France), O. Zolina found 50 stations which measure both Co-authors in the three PDO phases for both wind (Institut des Géosciences de variables on a daily basis for the period Carlos Batista Silva and geopotential height, while JRA55 l’Environnement, University of Grenoble, 2000-2013. Since Hall (2004) found shows the weakest anomalies. Beside Grenoble, France and P.P. Shirshov that 50% of the notal NH snow albedo The South America climatic behavior Institute of Oceanology, Moscow, on reversal Pacific Decadal Oscillation, the anomaly intensity, the position of the feedback caused by global warming strongest anomalies changes accordingly Russia), H.-W. Jacobi (Institut des occurs during NH spring, we focus on PDO, phases, from 1970 to 2003, is Géosciences de l’Environnement, analyzed in this study through composite the reanalysis dataset. the transition period of March to June University of Grenoble, Grenoble, (MAMJ). Here we use custom ERA- anomaly fields and the EOF technic. We In all the three PDO phases, JRA55 zonal France), E. Dutra (Instituto Dom Luiz, Interim land configurations with different used the reanalysis I of NCEP-NCAR, wind anomalies at low levels show a Faculdade de Ciências, Universidade de vegetation settings to compare in-situ ERA40 and JRA55 reanalysis datasets. westward displacement of the strongest Lisboa, Lisbon, Portugal) data to gridded products in respect to Considering geopotential height and negative and positive sign placed at the albedo and snow depth properties on wind variables, at low and high levels, northern South America in relation to the Global warming is enhanced at high daily and seasonal scales. all the three datasets present reversal NCEP-NCAR and the ERA40 reanalysis. northern latitudes where the Arctic climatic patterns on distinct PDO phases Also, the opposite sign placed over the surface air temperature has risen at We found a very good representation of (1970-1976, 1977-1996, 1997-2003), with equatorial eastern Pacific westward of twice the rate of the global average in daily snow variability and small absolute different intensities. the strongest anomaly observed in the recent decades – a feature called Arctic errors among different reanalyses. NCEP-NCAR and ERA40 datasets of amplification. This recent Arctic warming

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 120 Section 4

However, due to vegetation parameters, which translates into younger age- air studies based on observations and Jérôme Gourrion (Coriolis), Laurent albedo in reanalyses shows substantially of-air (AoA) values modelled in the differ from the results we obtain with the Parent (Mercator Ocean), Charly Régnier lower variability than in stations. For stratosphere. Nevertheless, balloon and corresponding climate data. (Mercator Ocean), Charles Desportes this, significant improvement was satellite observations do not agree with (Mercator Ocean) We will show that biases in the mean found between stations and grass- the widespread modelled trend towards AoA values are also different for these only configurations of ERA-Interim younger age-of-air for the recent past During the MyOcean project, several datasets compared to observations. land. Finally, snow albedo feedbacks in (Engel et al., 2009; Stiller et al., 2012; high resolution (1/4° horizontal grid) In addition we have used recent stations and grass-only configurations Haenel et al. 2015). ocean reanalyses based on the NEMO experimental datasets from the ECMWF are naturally higher than in “realistic” numerical ocean model and constrained Furthermore, a few recent studies with system to identify potential causes for configurations of ERA-Interim. by satellite observations and in situ T and chemistry transport models (CTMs) the differences in AoA distribution and S profiles, were produced with different driven by ERA-Interim reanalysis (Dee trends. The validation of our model tunings and by different institutes, and Stratospheric trends: Reanalysis et al., 2011) have also shown agreement results has been performed against were evaluated jointly using common v. climate models with the observed trends and not the new revised AoA dataset based on validation guidelines (Masina et al, 2015, with those from climate models (e.g. MIPAS SF6 observations (Haenel et al., DOI: 10.1007/s00382-015-2728-5). Author Beatriz Monge-Sanz Monge-Sanz et al., 2012; Diallo et al., 2015). Affiliation ECMWF 2012; Ploeger et al., 2015). To increase The Copernicus Marine Environment our confidence in climate-chemistry Monitoring Service CMEMS (marine. Co-authors The Copernicus Marine Service copernicus.eu) now takes advantage B. M. Monge-Sanz (ECMWF), D. Dee projections, the causes for the apparent Global Reanalysis Ensemble of the diversity of ocean reanalyses (ECMWF), H. Hersbach (ECMWF), disagreement in trends of age-of-air currently developed with that same A. Simmons (ECMWF), J. A. Parodi between observations and most climate Product GREPV1: deriving NEMO model grid (ORCA025 at 1/4°) (AEMET), P. Hitchcock (NCAR), F. Haenel models need to be identified. robustness estimates for ocean to propose a multi-model ensemble (KIT), G. Stiller (KIT), M. P. Chipperfield When evaluating different reanalysis currents and transports product. Four reanalyses are used; (U. Leeds), W. Feng (U. Leeds) products it is important to know, to the Author Marie Drevillon GLORYS2V4 from Mercator Ocean (Fr), possible extent, what differences among In the framework of the SPARC Mercator Ocean ORAS5 from ECMWF, FOAM/GloSea datasets are due to the differences in the Affiliation Reanalyses Intercomparison Project from Met Office (UK), and C-GLORS underlying numerical models, and what Co-authors from CMCC (It). The four different time (SRIP), we are evaluating the main Marie Drévillon (Mercator Ocean), differences are due to the assimilated series of global ocean monthly estimates reanalysis products of the world (Fujiwara Clément Bricaud (Mercator Ocean), Yann datasets of observations. have been post-processed to create et al., 2017) with a particular focus on Drillet (Mercator Ocean), Karina von the new product called GREP (Global their ability to reproduce stratospheric That is why in this study we have carried Schuckmann (Mercator Ocean), Gilles Reanalysis Ensemble Product), covering processes. out simulations with a CTM to assess Garric (Mercator Ocean), Simona Masina the stratospheric circulation with the the recent period during which altimetry In the present study we focus on the (CMCC), Andrea Storto (CMCC), Laura ERA-Interim dataset, as well as with data observations are available: 1993-2015. Brewer-Dobson circulation (BDC), Jackson (UK Met Office), Drew Peterson produced from an equivalent climate the major circulation pattern in the (UK Met Office), Richard Wood (UK Met The ensemble mean and standard system. AoA trends from our model stratosphere. Most climate models Office), Hao Zuo (ECMWF), Magdalena deviation of the ensemble, as well as the results with ERA-Interim fields are in have predicted an intensification of the Balmaseda (ECMWF), Stéphanie four individual members for the period good agreement with the recent age-of- stratospheric circulation with the increase Guinehut (CLS), Sandrine Mulet (CLS), 1993-2015, are thus made available on in greenhouse gases concentrations, a 1°x1° grid and monthly frequency.

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The time series will be extended by one the comparison of trend magnitudes Interim, for the period 1979-2010, where could improve the performance of year each year. In this presentation, among ERA-20CM and ERA-20C. ERA- these correlations are found not to be DMs. However, the skill of DMs is rather and in a series of companion posters, 20CM is a 10-member atmospheric statistically significant. On this respect limited due to significant uncertainties the ensemble mean performance will model integration forced by 10 different it appears that ERA-20CM produces a in inputs and complexity of dust cycle. be compared to that of the individual realisations of prescribed sea surface more consistent evolution of the HC than Furthermore, DM performance varies members, with respect to satellite temperature (HadISST2.1) and sea-ice ERA-20C and data assimilation weakens region to region. Hence, this study aims and in situ observations, and with 3D cover. dynamical links that would otherwise be to examine the performance of IFS in the temperature and salinity estimates present in model simulations. prediction of dust optical depth (DOD) in It is meant to provide a statistical deduced from observations with West Asia. estimate of the climate evolution and a statistical methods. good description of the low-frequency The evaluation of MACC/CAMS In addition, we draw a comparison Surface currents, heat and mass variability of the atmosphere during the dust optical depth reanalysis between IFS with two other DMs and transports, western boundary currents 20th century without assimilating any against deterministic and five statistical (regression and machine- variability, and tropical oceans variability atmospheric observations. ERA-20C is learning based) dust models using (El Niño, Atlantic and Indian ocean a deterministic reanalysis based on the statistical counterparts MODIS Deep blue (DB) Aerosol Optical dipoles) deduced from GREP will be same atmospheric model of ERA-20CM Author seyed omid nabavi Depth (AOD) as the representative of shown in this presentation. We will and forced by the same prescribed response variable While MACC/CAMS Affiliation University of Vienna explore, following Xue et al (2017, HadISST2.1 of the first member of the reanalyses perform better than other DOI: 10.1007/s00382-017-3535-y), the ERA-20CM ensemble. Furthermore, it Co-authors DMs (Spearman Correlation Coefficient possibility to use the spread in between assimilates marine surface winds and Seyed Omid Nabavi (Department of SCC of 0.62 and RMSE of 0.26), individual members in order to highlight surface and mean sea level pressure. Meteorology and Geophysics, University statistical models have yielded more robust signals. of Vienna, Vienna, Austria), Leopold accurate predictions (0.76 < SCC < 0.84 This analysis shows that the assimilation Haimberger (Department of Meteorology and 0.14 < RMSE < 0.21). of surface fields apparently introduces and Geophysics, University of Vienna, The effect of the data some spurious trends in the HC, Vienna, Austria), Reyhaneh Abbasi In addition, findings disclose that large assimilation on Hadley enhancing its multi-decadal and long- (Acoustics Research Institute, Austrian errors in the advection of dust by DMs Circulation variability and trends term variability. Its effect is particularly Academy of Sciences, Vienna, Austria), is the main reason of dust prediction strong on Southern HC, where its errors over affected areas (western in the 20th century and Cyrus Samimi (Department of strengthening is only supported by Geography, University of Bayreuth, Iran). Results also show high errors of Author Roberta D’Agostino ERA-20C and it is inconsistent with Bayreuth, Germany) the MACC/CAMS reanalyses over main the projected weakening of the tropical dust sources in Iraq. We believe that the Affiliation Max Planck Institute Principally, deterministic models (DMs) for Meteorology circulation. Assimilating surface omission of a spatio-temporal varying pressure and winds weakens the are being used to analyse and predict dust source function in the dust scheme Co-authors dynamical link between Southern HC dust concentration and optical depth at used by IFS has caused the significant R. D’Agostino (Max Planck Institute extent and meridional temperature finer spatial and temporal resolutions. miscalculation of emitted dust over main for Meteorology), P. Lionello (University gradient and extratropical tropopause sources. of Salento and CMCC) The assimilation of satellite and height in Southern Hemisphere, rising meteorological observations by The effect of the data assimilation inconsistencies among ERA-20CM analysis/prediction systems such as on Hadley Circulation (HC) and ITCZ and ERA-20C. Further, the analysis is the Integrated Forecasting System (IFS) variability has been investigated through extended to the ECMWF reanalysis ERA- used in the MACC and CAMS programs,

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 122 Section 4

with the ground-based observations such assessments is part of the GCOS and to a large extend explained. The The evaluations of surface among the latest satellite retrievals and guidelines for the generation of data results and the answers for TCWV are incident solar radiation among reanalyses. products. summarized as follows: On global ice- free ocean scale the trend estimates reanalyses, satellite retrievals The Rs from reanalyses have larger The GEWEX Data and Assessments among long-term data records were and ESMs uncertainties, because their cloud fields Panel (GDAP) has initiated the GEWEX generally found to be significantly were based on the model’s simulations in water vapor assessment (G-VAP) which Author Ma Qian different. Maxima in standard deviation the reanalysis systems. Finally, ground- has the major purpose to quantify the among the data records are found over, Affiliation BNU based observations of Rs and CERES current state of the art in water vapour e.g., tropical rain forests. These and other Co-authors EBAF Rs have been used to evaluate products (upper tropospheric humidity, noticeable regions coincide with maxima Qian Ma (Beijing Normal University), simulations of global climate models. specific humidity and temperature in mean absolute differences among Kaicun Wang (Beijing Normal University), profiles as well as total column water trend estimates. Martin Wild (Institute for Atmospheric and vapour) being constructed for climate Climate Science) The GEWEX water vapor applications. These distinct features can be explained assessment (G-VAP) – results with break points which manifest on In order to support GDAP and the A best effort was made to collect from inter-comparisons and regional scale and which typically do general climate analysis community ground-based measurements of not appear in stability analysis relative to stability analysis G-VAP intends to answer, among others, surface incident solar radiation (Rs). ground-based observations. Results from the following questions:a) How large are However, the distribution of observations Author Karsten Fennig profile inter-comparisons will also been the differences in observed temporal is still deficient on a global scale. Affiliation Deutscher Wetterdienst shown and exhibit, among others, that Alternatively, satellite Rs retrievals, which changes in long-term data records of Co-authors the observed break points are not only a employ sophisticated atmospheric water vapour on global and regional Marc Schröder (DWD, Offenbach, function of region but also of parameter. radiative transfer models with satellite scales?b) Are the differences in observed Germany), Maarit Lockhoff (DWD, observations of cloud and aerosol temporal changes within uncertainty Offenbach, Germany), Lei Shi (NOAA/ parameters used as input, can provide limits?c) What is the degree of The importance of reanalysis NESDIS/NCEI, Asheville, USA),Karsten globally gridded values of Rs. homogeneity (break points) of each long- monitoring: the example of ERA5 Fennig (DWD, Offenbach, Germany) term data record? A general overview Two sets of satellite retrievals of Rs from of G-VAP will be given. The focus of Author Andras Horanyi CERES EBAF and GEWEX-SRB (WCRP/ A large variety of water vapour data records is available to date. Without the presentation will be on observed Affiliation ECMWF GEWEX Surface Radiation Budget), were inconsistencies among long-term data compared with Rs values from ground- proper background information and Co-authors understanding of the limitations of records (eleven TCWV data records and A. Horanyi (ECMWF), P Berrisford based observations. Furthermore, seven specific humidity and temperature two reanalyses from ERA-Interim and available data records, these data may (ECMWF), G. Biavati (ECMWF), H. be incorrectly utilised or misinterpreted. profile data records, six of which are Hersbach (ECMWF), J. Muñoz-Sabater MERRA (Modern Era Retrospective based on reanalysis). Analysis for Research and Applications) The overall goal of assessments of CDRs (ECMWF), C. Peubey (ECMWF), R. Radu were evaluated with ground-based is to conduct objective and independent The inconsistencies are observed by (ECMWF), I. Rozum (ECMWF), D. observations. It shows that the CERES evaluations and inter-comparisons in inter-comparisons, comparisons to Schepers (ECMWF), A. Simmons EBAF Rs has a better comparison order to point out strengths, differences in-situ observations and the stability (ECMWF) and C. Soci (ECMWF) and limitations and, if possible, to analysis. On basis of consistently applied provide reasons for them. The need for tools major differences in state-of-art CDRs have been identified, documented

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The ERA5 reanalysis (implemented by and values of NE, SE, CE as well as with the Copernicus Climate Change Service The link between the tropical ψN, while correlation between the total The NASA/NCCS Collaborative on behalf of the European Commission) precipitation and Hadley precipitation and ψS is weaker. Reanalysis Technical is in production at the European Centre circulation: comparing ECMWF All correlations are stronger in the boreal Environment for Medium-Range Weather Forecasts reanalysis ERA-20C and ERA- winter while in summer they become (ECMWF). The scientific validation of Author Gerald Potter not significant with bothψ N and ψS. In the particular model version used is Interim to the AMIP-like Affiliation NASA/GFSFC ERA-20C and in ERAInterim there is a followed by the routine monitoring of experiment ERA-20CM correlation between total precipitation Co-authors the production suites of the system. Author Ascanio Luigi Scambiati in the deep tropics and values of CE G.L. Potter (NASA/GSFC), L. E. M. The monitoring activity is focusing on Affiliation Università del Salento and N, whereas the correlation with Carriere (NASA/GSFC), J.A. Hertz the observation usage of the system as ψ NE and SE becomes not significant and (NASA/GSFC) compared to ERA-Interim and ECMWF Co-authors vanishes in boreal summer. Further, the operations, the observation departures A.L. Scambiati (University of Salento, In order to simplify access to correlation between CE, NE, SE and the from the first guess and the analysis CMCC), R. D’Agostino (MPI), P. Lionello multiple reanalyses, the NASA/NCCS position of the precipitation maximum and on the analysis increments and (University of Salento, CMCC) Collaborative REanalysis Technical located near the Equator and north and differences as compared to other Environment (CREATE) has repackaged This contribution investigates the south hemisphere precipitation minima, reanalysis systems at ECMWF. selected fields from the world’s major reproduction of the link between respectively are investigated. In ERA- reanalysis efforts and published 6-hour The presentation will provide a brief intensity of zonally averaged tropical 20CM the correlations are significant and monthly data in the Earth System overview of the monitoring tools used precipitation and Hadley Circulation (HC) only in the boreal winter, in ERA-20C the Grid Federation (ESGF). for ERA5 and an insight into how the width and intensity in ECMWF ERA-20C correlations remains significative only for monitoring activity is organised. Some and ERAInterim at seasonal scale. The the CE and SE and in ERAInterim only for The reanalysis data is presented in a examples will be shown focusing on reanalyses are compared to the ERA- the SE. All these outcomes suggest that similar way as the CMIP3 and CMIP5 when monitoring proved to be essential 20CM (AMIP-experiment) data. The HC data assimilation reduces a dynamical archives, using standardized Climate to detect problems and deficiencies of monthly mean mass stream function ψ link that would otherwise be present in and Forecast (CF)-compliant variable the ERA5 production suites. is computed and the HC Central Edge the atmospheric circulation model. names and consistent metadata. Along (CE), the Northern Edge (NE) and the with easy access, CREATE’s processing Southern Edge (SE) are defined as the and interface enable comparing multiple zero-crossing latitudes of ψ bulk, where reanalysis data sets with each other and ψ bulk is the average of ψ between 150 with climate and weather model output. and 700 hPa. The data is published one variable per file on the native horizontal grid and in The strength of the HC is given by the vertical pressure levels. maximum and minimum values of ψ in the Northern Hemisphere (ψN) and An ancillary project has produced a Southern Hemisphere (ψS), respectively. similar product of the temperature, In ERA-20CM results show a large salinity, and velocity fields for the major correlation between the total precipitation ocean reanalyses. In addition to the in the belt 10°N – 10°S (deep tropics) native grids, the ocean reanalyses are also regridded to a common vertical and

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 124 Section 4 horizontal grid. The ESGF data interface the observed trends and we use models trends at most stations in southeastern Tropical Easterly Jet (TEJ) is one of is widely accepted throughout the to assess information about the quality of China in spring and in northernChina in the principal components of the Indian international climate research community reanalyses trends. summer. summer monsoon (ISM), which shows and provides a variety of tools for large temporal and spatial variability In the lower troposphere (850 and 700 access. Procedures for downloading, over the Indian subcontinent. The TEJ hPa), most stations over China exhibit viewing, and manipulating the data will Trends in the Frequency of High is located in the upper troposphere positive trends in summer, autumn, and be demonstrated. Relative Humidity over China: between 14-17 km region and is a winter. For the midtroposphere (500– 1979–2012 consequence of intense heating over 400 hPa), increasing trends dominate the Tibetan plateau during the boreal Author Rui Mao overChina in spring, summer, and The role of stratospheric summer. Due to this intense heating and autumn. dynamics on the climate system Affiliation Beijing Normal University action of Coriolis force, the TEJ develops in response to Antarctic ozone Co-authors Finally, six reanalysis datasets, the over the Indian summer monsoon trends: CMIP5 versus Dao-Yi Gong(Beijing Normal University, NCEP–NCAR, NCEP–DOE,CFSR, ERA- region and plays an important role in Reanalyses China), Tianbao Zhao (Institute of Interim, MERRA, and JRA-55 datasets, vertical development of clouds and their Atmospheric Physics, Chinese Academy were compared with the observed distribution. Author Chiara Cagnazzo of Sciences, China), Wenshan Wang increasing trends inHRH frequency in One more important aspect of TEJ is ISAC-CNR (Department of Earth System Science, the low-to-middle troposphere. Similar Affiliation its ability to excite the gravity waves, University of California, Irvine, Irvine, increasing trends in HRH frequency in the Co-authors which couples the lower and middle California), Jing Yang(Beijing Normal reanalysis datasets and the homogenized C. Cagnazzo (ISAC-CNR), G. Rea atmosphere. Thus it is very important to University, China) humidity data are observed in certain (ISAC-CNR), F. Fierli (ISAC-CNR) characterise the TEJ at various temporal seasons and for certain regions. These and spatial scales to quantify their role In this work we analyze how CMIP5 High relative humidity (HRH) is defined results are consistent with the increasing in driving the ISM. Reanalyses datasets models represent the stratospheric as a relative humidity of at least 80%, low-to-middle cloud amounts in recent provides valuable information on the TEJ dynamics and specifically the lower which is often associated with the decades. strength, its core location and variability. stratospheric cooling observed in occurrence of cloud layers. Thus, the There are considerable amount of summer since 1979 to 2001 over frequency of HRH and its changes in studies on TEJ using reanalysis Antarctica, an important aspect the troposphere may be related to the Tropical Easterly Jet: Spatial and datasets, However, a comprehensive associated the austral springtime ozone occurrence frequency of cloud layers and Temporal Variabilities in evaluation of reanalysis datasets for hole. We find that models with a well- their changes. Reanalysis and Observations TEJ characterisation is yet to be carried resolved and a chemical representation In this study, trends in the frequency Author Kishore Kumar Karanam out. In this regard, the present study of the stratosphere better represent of HRH (defined as days with relative evaluates the capability of four reanalysis the lower stratospheric cooling, when Affiliation Indian Space Research humidity $80%) over China from the datasets viz., NCEP, ERA, MERRA-2 and compared to reanalyses. Organization surface to the midtroposphere($400 hPa) JRA-55 in extracting the TEJ features at Co-authors from 1979 to 2012 were analyzed using a various temporal scales using radiosonde However, there is a large range of trends Kandula Venkata Subrahmanyam (Space homogenized humidity dataset for spring as well as radar observations over the among reanalysis data sets. Here we use Physics Laboratory, Vikram Sarabhai reanalyses to estimate uncertainties in (March–May),summer (June–August), Indian region. autumn (September–November), and Space Centre, Trivandrum, India) winter (December–February). The results for the ground level indicate decreasing

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The similarities/discrepancies in and continents in MERRA-2, and also Goddard Space Flight Center, Greenbelt, zone. But a key focus of temperature characterizing the TEJ among the in a newly developed MERRA-2 AMIP Maryland), S.M.J. Nowicki (Cryospheric differences for northern high latitudes reanalysis datasets with respect to ensemble simulation (M2AMIP). Sciences Laboratory, NASA Goddard is the Arctic Ocean. Near-surface observations is extensively evaluated Space Flight Center, Greenbelt, air temperature differences over the M2AMIP uses the same model and at diurnal to interannual time scales. Maryland) Arctic Ocean are found to be related spatial resolution as MERRA-2, After evaluating the reanalysis datasets, to discrepancies in sea ice and sea producing the same output diagnostics they are used to study the long-term Reanalyses in the Arctic are widely surface temperature boundary data, over 10 ensemble members. Composite changes in TEJ strength and its location. used for model evaluation and for which are severely compromised in El Niño temperature data are compared An attempt is also made to study the understanding contemporary climate current reanalyses. Issues with the with observations to evaluate the land/ TEJ features with respect to interannual change. Nevertheless, differences among modeled representation of sea ice cover sea contrast, variations and phase variability of ISM in all the four reanalysis reanalyses in fundamental meteorological are an additional factor in reanalysis relationship. The temperature variations datasets. The significance of the present variables including surface air temperature trends. Differences in the are related to surface heat fluxes and the study lies in evaluating the four reanalysis temperature are large. For example, the representation of the surface energy atmospheric temperatures and transport, datasets for TEJ characterization using 1980-2009 mean surface air temperature budget among the various reanalyses are to identify the processes that lead to radiosonde and radar observations at for the north polar cap (70°N-90°N) also reviewed. the lagged redistribution of heat in the diurnal to interannual timescales, which among global reanalyses span a range of tropics and beyond. is envisaged to shed light on role of TEJ 2.4 K, which approximates the average in driving the ISM variability. Discernable cloud, radiation and data warming trend from these reanalyses Unprecedentedly weak assimilation changes accompany the over the 30-year period of 2.1 K. Indonesian Throughflow during onset of El Niño affecting continental 2015/16 speeds up Tropical Tropical Energy Variability in Understanding these differences requires regions through the progression to evaluation over the three principal Pacific heat recharge after El Niño MERRA-2 and M2AMIP and following the peak values. While surface domains of the Arctic: glaciated Author Michael Mayer Author Michael Bosilovich the model represents these variations land, the unglaciated terrestrial surface, in general, regional strengths and Affiliation ECMWF Affiliation NASA GSFC GMAO and sea ice/ocean. An examination weaknesses can be identified. is conducted of contemporary global Co-authors Co-authors reanalyses of the ECMWF Interim project, M. Mayer (ECMWF/Univ. Vienna), M.G. Bosilovich (NASA GSFC GMAO), NASA MERRA, MERRA-2, JRA-55, and M.A. Balmaseda (ECMWF), F.R. Robertson (NASA MSFC) Understanding Arctic surface NOAA CFSR using available in situ data L. Haimberger (Univ. Vienna) temperature differences in Studies have shown the correlation and and assessments of the surface energy reanalyses budget. Overly-simplistic representations The 2015/16 El Niño event exhibited peak connection of surface temperatures sea surface temperature (SST) anomalies across the globe, ocean and land, related Author Richard Cullather of the Greenland Ice Sheet surface are found to be associated with local warm similar to the record-breaking 1997/98 to Tropical SSTs especially El Niño. This Affiliation ESSIC/University of air temperature biases in winter. event. Here we employ atmosphere and climate variability greatly influences Maryland at College Park ocean reanalyses from ECMWF (ORAS4, regional weather and hydroclimate Co-authors A review of progress made in the ORAS5, ERA-Interim) and JMA (JRA-55) extremes (e.g. drought and flood). In this B. Zhao (Global Modeling and development of the MERRA-2 land- in conjunction with satellite data (CERES- paper, we evaluate the relationship of Assimilation Office, NASA Goddard ice representation is presented. Large EBAF) to compare anomalous energy temperatures across the tropical oceans Space Flight Center), C.A. Shuman uncertainty is also found in temperatures flows through the climate system during (Cryospheric Sciences Laboratory, NASA over the Arctic tundra and boreal forest these two El Niños.

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This perspective is only possible thanks As a result, the 2015/16 El Niño left convective depth in control simulations assessed. We use an ensemble of global to the revolution on the ocean observing the Pacific in a state recharged for the for determining the response. An attempt ocean reanalyses in comparison with systems and analysis capabilities in real occurrence of another El Niño event, only to falsify models with reanalysis data observations in order to examine recent time. We show that despite its extreme two years after the previous one. This suggests a way forward. changes in the North Atlantic. surface characteristics, there was no conclusion is supported by seasonal In particular we assess changes in the longer lasting cooling of tropical Pacific prediction systems that – at the time AMOC strength as observed by the subsurface waters associated with the of writing – indicate the possibility of Using a multi-model ensemble of RAPID array, changes in Atlantic ocean 2015/16 El Niño. another El Niño event for the winter ocean reanalyses to understand heat content and changes in North 2017/18. recent changes in the North In fact, tropical Pacific upper ocean heat Atlantic convection. content (OHC) at the end of 2016 was Atlantic ocean. higher than at the beginning of 2015 Use reanalysis to constrain Author Laura Jackson by about 7.1±0.5 ZJ, which is in stark Validation of reanalysis against climate model projection of Affiliation Met Office variability and trends of in situ contrast to statistical expectation and Sahel rainfall response to previous big El Niño events like that in Co-authors stations temperature time-series 1997/98 (-15.7±4.3 ZJ OHC loss). The uniform ocean warming LC Jackson (Met Office), C Dubois in the western half of Iran (Mercator), LC Allison (Met Office), KA main reason for this surprising result Author Yi Ming is the unprecedented reduction of Peterson (Met Office) Author Piero Lionello Affiliation NOAA/GFDL Indonesian Throughflow (ITF) volume Affiliation University of Salento Co-authors The observational network around the (-20%) and associated heat transport Co-authors Yi Ming (NOAA/GFDL, Princeton North Atlantic has improved significantly (-25%) during 2015/16. Although S. Sadrafshari (Zanjan University, Iran), University) over the last few decades with the advent weakening of the ITF is typical for El Niño of ARGO and satellite observations, L.Scarascia (CMCC, Italy), P.Lionello events, the amount of heat retained in the Coupled climate models project future and the more recent efforts to monitor (University of Salento,Italy) Pacific by reduced ocean energy export changes to rainfall in the African Sahel the Atlantic Meridional Overturning Iran appears to be a critical host spot was exceptional during 2015/16 and ranging from severe drying to severe Circulation (AMOC) using arrays such as of climate change. In fact, it is located explains 83% of the found difference in wettening. Atmosphere-only models RAPID and OSNAP. These have shown in the central part of a stripe going from OHC changes. perturbed with uniform ocean surface decadal timescale changes across the the Arabian Peninsula to the Eurasian warming span a similar range, motivating North Atlantic including in heat content, The reduction of the ITF transports was steppe characterized by steep increase study of the simpler latter problem in heat transport and the circulation. related to the observed strong warming of temperature in the second half of order to constrain the more societally of the eastern Indian Ocean in recent However there are still significant the 20th century. Here we investigate relevant former one. years, which enhanced anomalous sea gaps in the observational coverage, to which extent the ERA-Interim (the level gradients across the Indo-Pacific We analyze two comprehensive and significant uncertainties around continuously updated ECMWF 1979-to- Warm Pool. Increased absorption of atmospheric models developed at the some observational products. Ocean present reanalysis), ERA20C and 20CR solar radiation consistent with positive NOAA Geophysical Fluid Dynamics reanalyses integrate the observations (ECMWF and NOAA ESRL 20th century SST anomalies prevailing in the eastern Laboratory, which respond to uniform with a dynamically consistent ocean re-analyses) reproduce the temperature subtropical Pacific was a secondary ocean surface warming of 2 K with model and are potentially tools that can behavior during the period 1979-2010 effect damping the tropical pacific OHC Sahel wet season rainfall changes quite be used to understand the observed that is recorded at 15 meteorological discharge. differently. A detailed MSE budget changes, however the suitability of the stations in the western half of Iran. analysis reveals the importance of reanalyses for the task must also be

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 127 Section 4

Results are not free of problems. For all Observed wave spectra characteristic Modern scientific visualisation methods stations ERA-Interim and Era 20C are Validation of the SWAN model parameters were compared with the ones offer a powerful tool for analysis and systematically biased low with respect with wave spectra observation in simulated through the regional numerical comparison. Careful choice of colour and to observations, while 20CR biases are the Arvoredo marine biological propagation wave model SWAN with a 20 structure allows plots capturing spatial locally large, but with different signs in reserve, Santa Catarina, Brazil meter resolution allowing to investigate detail for several variables simultaniously, different parts of the area, so that the the model reliability such as the and video shows their time-evolution. overall bias is actually smaller than the Author Pietro Albano robustness of the boundary conditions. two other datasets. Correlation between Affiliation BMingegneria The results show a good agreement re-analyzes and observed time series has between observed and simulated wave WCRP Task team for the Co-authors in general a seasonal connotation, with data with mean square error and bias for Intercomparison of ReAnalyses Pietro Albano (Was with Lahimar-UFSC low values in summer and high values in the significant wave height of 0.3 and 0.2, (TIRA): Motivation and Progress now he is with BMingegneria), Davide winter. respectively. As for the peak period, a Franco (Lahimar-UFSC), Alejandro Author Michael Bosilovich mean square error and a bias of 1.9 and For almost all stations ERA-Interim Donnangelo (Lahimar-UFSC) 0.8 seconds were instead calculated. Affiliation NASA GSFC GMAO presents the largest correlation among Low frequency wave energy coming Co-authors the three datasets. However, considering This study provides a comparison from E-ESE and SES-S bins presents TIRA Membership trends, there is a large discrepancy between wave observations in shallow water and wave data simulated through the highest mean square error in the between the small values of 20CR (with Reanalyses have proven to be an the SWAN model, forced in deep water spectra. This is due to the Arvoredo annual values close to 2K/century) and important resource for weather and by Hindcast reanalysis directional wave Island which creates a diffraction pattern the very large trends of ERA20C and climate related research, as well as spectra of the WW3_NOOA model. From that causes a wrong estimate of the peak ERA-Interim (around 6.5 and 8.5K/ societal applications at large. Several March 2014 until April 2016, within the direction, highlighting the importance of a Century, respectively). CRU trends are centers have emerged to produce new MAArE project, it has been possible multimodal wave spectra identification. large as well (slightly below 6K/Century) atmospheric reanalyses in various to characterize the wave regime in the and much closer to trends in ERA20C forms every few years. In addition, land marine biological reserve of Arvoredo, and ERA-Interim than to 20CR. Visual analysis and ocean communities are producing situated 11 Km north of the island of disciplinary uncoupled reanalyses. Differences among trends are mostly Florianopolis, in the south Brazilian Author Philip Brohan related to the two last decades of the Current research and development in shore. Affiliation Met Office Hadley Centre 20th century, when the behavior of reanalysis is directed at (1) extending the ERA-Interim and ERA20C has been The two years survey was carried out Co-authors length of reanalyzed period and (2) use of characterized by a very large negative by an Acoustic Doppler Profiler (ADP) Philip Brohan (Met Office Hadley Centre) coupled Earth system models for climate bias with respect to observations, which located at a depth of 21 meters and reanalysis. it allowed to analyse the directional One of the strengths of reanalyses is in has been decreases rapidly (without While WCRP’s involvement in the wave spectra characteristic parameters their detail – they describe the complex anyway vanishing) afterwards. On the reanalyses communities through its through the extended maximum entropy structure of the atmosphere, showing the contrary, ERA20C time series show Data Advisory Council (WDAC) has been method (Haschimoto et al., 1994). Local behaviour of many variables on a range a flatter behavior than other datasets substantial, for example in organizing wave regime mainly showed east seas of space and time scales. This strength during the whole period. international conferences on reanalyses, with a period between 6 and 8 seconds makes them difficult to appreciate and a central team of reanalyses expertise is and significant wave height between 0.5 inter-compare – it is hard to capture their not in place in the WCRP structure. The and 1 meter. value and accuracy in simple numerical metrics. differences among reanalyses and their

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 128 Section 4 inherent uncertainties are some of the It is considered in 5 layers in spherical most important questions for both users Wind effect on changes of coordinate with sigma vertical and developers of reanalyses. salinity and temperature in a component and wind blow steady all over basin surface during 4 days. Results Therefore, a collaborative effort to theoretical oceanic model with show quality of changes in diffusion of systematically assess and intercompare none-level bottom temperature and salinity each layer along reanalyses would be a logical Author Zohre Heydari Neshe longitude and latitude. progression that fills the needs of the community and contributes to the Affiliation Khorramshahr University WCRP mission. The primary charge of marine science and to the TIRA is to develop a reanalysis technology intercomparison project plan that will Co-authors attain the following objectives. Zohre Heydari Neshel (PhD student in Khorramshahr University), Mohammad 1) To foster understanding and Taghi Zamanian (Faculty of Marine and estimation of uncertainties in Oceanic Science, Khorramshahr reanalysis data by intercomparison University of marine science and and other means. technology) 2) To communicate new developments and best practices among the The subject of this study is 3D modeling reanalyses producing centers. of density changes and double diffusion of salinity and temperature in a marine 3) To enhance the understanding of rectangular basin with closed boundaries data and assimilation issues and and none-level bottom on longitude: 47° their impact on uncertainties, leading to 58° E and latitude: 24° to 30° N. to improved reanalyses for climate assessment. Basin bottom is elliptical and non-level, maximum depth in center of bottom 4) To communicate the strengths is 116.95m and increasing distance of and weaknesses of reanalyses, center, decreasing in depth and minimum their fitness for purpose, and best depth is equal to 35.07 m. Basin bottom practices in the use of reanalysis is rectangular and non-level bottom and datasets by the scientific community inversion. Minimum depth in center is This presentation outlines the need equal to 6.58 m; away from center, depth for a task team on reanalyses, their increase to maximum equal to 112.77 m. intercomparison, the objectives of the team and progress thus far.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 129 The model simulation capability of the This creates a temporally and spatially Section 5 – precipitation and the vortex moving A temporally and spatially varying ELR, that can be used to Applications of path using different initial conditions varying environmental lapse-rate downscale near-surface air temperature are compared, the impact on the for temperature downscaling from the reanalysis resolution to higher reanalyses structure evolution character of SWCV by resolutions. This approach could replace assimilating intensive sounding data and Author Emanuel Dutra the commonly used global constant ELR A numerical study on Southwest its influence mechanism are analyzed. Affiliation Instituto Dom Luiz, of 6.5 K km-1 by an ELR based on local Faculdade de Ciências, meteorological conditions. China Vortex (SWCV) scientific The result shows: the forecast capability Universidade de Lisboa experiment data assimilation of precipitation and the moving path The ELR estimates based on ERA5 in a heavy rainfall event caused of plateau vortex(PV) and SWCV are Co-authors and ERA-Interim were compared with by vortex and its influencing improved by assimilating both intensive E. Dutra (1), J. Muñoz-Sabater(2), S. observationally based ELR over the Boussetta(2), T. Komori(3), S Hirahara (3), mechanism sounding data and the conventional U.S. using the GHCN temperature data, data, a worse forecast is produced by and G. Balsamo (1)1- Instituto Dom Luiz, showing a good agreement. The method Author Duming Gao assimilating operational sounding data Faculdade de Ciências, Universidade de is used to downscale ERA5 to about 9 Affiliation Institute of Plateau individually; by introducing intensive Lisboa2- European Centre for Medium- km globally and validated against in-situ Meteorology, China sounding data, the strength of initial Range Weather Forecasts3- Global temperature observations and compared Meteorological plateau vortex(PV) and SWCV are Environment and Marine Department, with simulations without any topographic Administration(CMA) enhanced due to the increase cyclonic Japan Meteorological Agency correction and with a constant ELR. perturbation on the initial wind field, Co-authors Temperature near the surface varies with The results suggest some benefits besides, the more unstable stratification Duming Gao (Institute of Plateau altitude accordingly to the environmental of using this new ELR over complex adjusted by data assimilation makes Meteorology, China Meteorological lapse-rate (ELR). The ELR depends terrain regions, when compared with a the model more easy to produce large Administration (CMA)), Yueqing on the overlying air masses, large- constant value, and suggest that this precipitation in initial times as the Li(Institute of Plateau Meteorology, China scale situation and local effects. The new methodology could be used as a observation’s magnitude. Meteorological Administration( CMA)) characterization of the ELR has several default for downscaling temperature The experiment reveals the generation applications, in particular to downscale from reanalysis on the global/regional Based on the Weather Research and maintenance of SWCV on 700hPa global/regional numerical weather scale where local in-situ observations are Forecast(WRF) model and WRF data in this case is not rely on high potential predictions, and reanalysis in complex scarce and computational resources limit assimilation system(WRFDA), an vorticity on upper air, it must need terrain regions. dynamical downscaling. sensitivity analysis is conducted in a positive vorticity transported by the From an observational point of view, data assimilation experiment using enhanced vertical movement which complex terrain regions also constitute operational sounding data and the caused by latent heat release of a challenging environment due to the intensive observed data of Southwest precipitation condensation. China vortex(SWCV) scientific experiment difficulties associated with the installation on a heavy rainfall caused by vortex in and maintenance of observational Sichuan Basin. networks. In this study we propose the derivation of the ELR from the reanalysis lower troposphere vertical profiles of temperature.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 130 Section 5

None of the reanalysis datasets mainly between 1994 and 2009. Using An assessment of trends in the assimilate surface temperature data, Analysis of possible effects of meteorological stations data of near annual cycle of temperature but they differ in the data that are temperature change on the sub-basins and data from the NCEP across the Northern Hemisphere assimilated: both ERA-20C and 20CR temporal and altitudinal Reanalysis database, the trends of the assimilate surface pressure data; ERA- dynamics of agricultural areas in increase of the temperatures showed Author Richard Cornes 20C also includes surface wind data values of 1 °C in the reference period Affiliation KNMI over the oceans; ERA-20CM does not the Andes of southern Peru and anomalies of 0.02 to 0.04 °C were Co-authors directly assimilate any of these synoptic Author Alexis Nicolas Ibañez described. data. As such ERA-20CM is viewed as Richard Cornes (Royal Netherlands Blancas Through the thermal bands of the a form of control, in the sense that the Meteorological Institute), Phil Jones Affiliation Centro de Investigaciones Landsat images and the application data are not constrained by observed (Climatic Research Unit, University of de Zonas Aridas of the standard deviation of the MSLP or marine wind data, as is the case East Anglia), Cheng Qian (CAS Key temperature, it was determined that with the other reanalyses. Most previous Co-authors Laboratory of Regional Climate- the area with the greater variation of analyses of the annual cycle have only Alexis Ibanez (CIZA UNALM), Grégry Environment for Temperate East Asia, temperature, between 2 and 4 °C, was examined changes over the latter half of Damman (CIZA UNALM), Maria Fernanda Institute of Atmospheric Physics, Chinese located in the altitudinal range of 3600 the twentieth century, but the century- de los Rios (CIZA UNALM) Academy of Sciences; and University to 4000 meters. The data obtained show long view afforded by these reanalyses of Chinese Academy of Science) The study of the effect of the temperature an increase in temperature variability, has allowed us to examine trends in the change on the dynamics of ecosystems which could be influencing an increase The annual cycle of temperature annual cycle back to 1902. is getting attention in a context of in the use of agricultural lands at higher accounts for more than 90% of the It is demonstrated from the comparison climate change. This effect may be more altitudes in the Vilcabamba sub-basin. variance of surface air temperature of these datasets that much of the sensitive for mountain ecosystems, This situation would cause a change across extra-tropical regions. interannual to lower-frequency variability especially because of the altitudinal in the vegetation found naturally in the Observations have indicated profound in the amplitude of the annual cycle is gradient. In the Peruvian Andes, highlands, affecting ecosystem services changes in the annual cycle throughout attributable to synoptic variability, with having tropical mountains, the effect of that the area offers. the twentieth century, but the factors oceanic coupling being the critical factor. temperature variation may be more easily influencing these trends remain poorly Furthermore, the variability in the phase observable. The present work aims to understood. In this analysis we evaluate and amplitude of the annual cycle during describe the dynamics of agricultural these changes in the annual cycle the post-1950 period was unusual in the areas in the southern Peruvian Andes, in through the comparison of four reanalysis context of the twentieth century, although the Vilcabamba river basin, from 1986 to datasets (ERA-20C, ERA-20CM and two uncertainty is greatest before ca. 1930 2009. It also looks forward to explain the versions of NOAA-20CR) against the as a result of relatively sparse data possible effects of temperature change CRU-TS dataset. coverage during across most regions of on agricultural areas in the gradient The Modulated Annual Cycle (MAC) is the northern hemisphere. between 2400 and 4000 meters. calculated from the data using Ensemble With the use of Landsat and ASTER Empirical Mode Decomposition (EEMD), images, the land use changes in relation from which phase and amplitude metrics to height was modeled. It showed are derived. an increase on agricultural area use between the 3600 and 4000 m.a.s.l.,

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 131 Section 5

Analysis of mean state of SST and sea Major issues in the reanalyses are extratropical cyclones and anticyclones Assessment of different ocean surface salinity (SSS) reveals that ORAS4 underestimation of upper ocean stability shows the flow of vapor transport in a reanalyses over the Tropical is better comparable with observations/ and surface current in EIO and over narrow channel approximately 450 km Indian Ocean EN4 data, which is followed by SODA, estimation of vertical shear of current in width and 2600 km in length. The ECDA and GODAS. The surface and variability of different physical precipitation resulting from the inland Author ANANYA KARMAKAR circulation in ORAS4 is closer to OSCAR oceanic variables. To improve the skill of penetration of this AR is also analyzed. Affiliation Indian Institute of Tropical compared to the other reanalyses. reanalyses over the TIO, salinity vertical To consider this event in a climatological meteorology However mixed layer depth (MLD) is structure and upper ocean circulation context, IWV and IVT data are derived better simulated by SODA, followed by need to be better represented. Co-authors from ECMWF for the month of February ECDA, ORAS4 and GODAS. Ananya Karmakar (Indian Institute of over the 20-year period from 1996- Tropical Meteorology (IITM), Pune- Seasonal evolution of error indicates that Atmospheric River Event over 2015. Dates of observed landfalling 411008, India, Department of the highest deviation exists during spring the Eastern Pacific in February ARs for water years (WYs) 1998-2008 Atmospheric and Space Sciences, and summer in SST and MLD over the 2014: Analysis and that impacted the California coast Savitribai Phule Pune University, Pune TIO in GODAS. These errors may play (32.5N-41.0N) are obtained from SSM/I. -411007), Anant Parekh (Indian Institute of very decisive role since GODAS (during Climatological Context Dates for February 1996-1997 and Tropical Meteorology (IITM), Pune- spring) is widely used to initialize the Author Deveshi Buch 2009-2015 are based on ECMWF with 411008, India), J. S. Chowdary (Indian coupled models for seasonal prediction the constraint that IWV >20 mm for Institute of Tropical Meteorology (IITM), Affiliation Vista del Lago High of Indian summer monsoon. Statistical School observations that are 12 hrs. apart. Pune- 411008, India), and C. analysis with concurrent data of EN4 for It is observed that the February 2014 AR Gnanaseelan (Indian Institute of Tropical the period of 1980-2010 supports that Co-authors event is one of five significant events in Meteorology (IITM), Pune- 411008, India) the difference and standard deviation D Buch (Vista del Lago High School) the 20-year period, as measured by IWV (variability strength) ratio for SSS and This study makes an inter comparison Atmospheric rivers (ARs) are narrow and >30 mm. An algorithm was developed MLD is mostly greater than one. of ocean state of Tropical Indian Ocean intense plumes of water vapor that are to filter the raw data in order to meet a (TIO) in different ocean reanalyses such In general the strength of variability is known causes of heavy precipitation threshold of >20 mm (IWV) and >250 as Global Ocean Data Assimilation over estimated by all the reanalyses. events. This is an analysis of the kgm-1s-1 (IVT) for a duration of >12 hrs. System (GODAS), Ensemble Coupled Further analysis with in-situ buoy evolution, transport, and landfall of a to expose values that represent AR Data Assimilation (ECDA), Ocean observations supports that MLD errors significant AR event in February 2014 events. A composite mean of the IVT Reanalysis System 4 (ORAS4) and over the equatorial Indian Ocean over the Eastern Pacific and West Coast values is also calculated, showing peak Simple Ocean Data Assimilation (SODA) (EIO) and Bay of Bengal are higher of the United States, considered in a IVT of 500-600 kgm-1s-1 at the core of with reference to the in-situ buoy than estimated with respect to EN4 climatological context. the composite AR. observations, satellite observed Sea data. Overall ORAS4 displays higher Integrated Water Vapor (IWV) and Surface Temperature (SST), EN4 data, correlation and lower error among all Integrated Vapor Transport (IVT) values and ocean surface current analysis real reanalyses with respect to both EN4 data are calculated based on NASA MERRA time (OSCAR). and buoy observations. and ECMWF ERA-Interim reanalysis datasets. The AR is characterized by high levels of IWV (~29 mm) as well as IVT (~759 kgm-1s-1). Analysis of the synoptic-scale progression of upper-level

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 132 Section 5

This study explores a novel technique to derived from about 130 Chinese stations Can satellite altimetry and use satellite observations of sea surface Changes of atmospheric were homogenized using a new approach gravimetry data be used to height (SSH) anomaly from altimetry precipitable water in developed by Dai et al. (2011). and ocean bottom pressure (OBP) from evaluate the quality of Arctic- observations and reanalysis over It is shown that the homogenization satellite gravimetry to evaluate the quality Ocean satellite sea surface China removes the large shifts in the original of satellite SSS. The method is based records of humidity resulting from sonde salinity? – insight from ECCO on regional relationships of SSS and Author Tianbao Zhao changes in recent years in China, and it state estimation SSH-OBP anomalies inferred from ECCO Affiliation Institute of Atmospheric improves correlation of the precipitable Version-4 ocean-ice state estimation Author Tong Lee Physics (IAP), Chinese water (PW) with precipitation and the product, which reproduces the observed Affiliation Jet Propulsion Laboratory Academy of Sciences spatial coherence of the PW trend during vertical salinity structure and changes in (CAS) recent 40 years. The PW variations Co-authors SSH and OBP anomalies reasonably. Can satellite altimetry and gravimetry Co-authors and changes are highly correlated with data be used to evaluate the quality of The physical basis is that (1) SSH- Tianbao Zhao (Institute of Atmospheric those in lower–midtropospheric mean Arctic-Ocean satellite sea surface OBP anomalies reflect steric change Physics, Chinese Academy of Sciences, temperature (r = 0.83), with a dPW/dT salinity? – insight from ECCO state integrated over the water column, which Beijing, China) Aiguo Dai (Department of slope of ~7.6% K−1, which is slightly estimation is mostly due to salinity change in the Atmospheric and Environmental higher than the 7% K−1 implied by Arctic Ocean; (2) Arctic-Ocean SSS is a Sciences, University at Albany, SUNY, Clausius–Clapeyron equation with a Arctic Ocean freshwater content and good proxy of steric changes due to the Albany, New York, USA) constant relative humidity (RH). distribution are changing due to the weak vertical stratification compounded The radiosonde data show only combined effects of atmospheric, by vertical mixing. Analysis of the ECCO Radiosonde humidity data provide the small variations and weak trends in hydrologic, and cryospheric forcing. product confirms the aforementioned longest record for assessing changes in tropospheric RH over China. Using these These changes can impact North physical basis and illustrates significant, atmospheric water vapor, but they often homogenized observations, the PW from Atlantic Ocean circulation and the high correlations between SSS and contain large discontinuities because the NCEP/NCAR, NCEP/DOE, MERRA, related transports of heat, freshwater, SSH-OBP anomalies along the shelf of changes in instrumentation and JRA-55, JRA-25, ERA-Interim, ERA-40, carbon, and nutrients that have potential seas. Moreover, the large regression observational practices. CFSR and 20CR reanalyses is evaluated influence on climate and weather as well coefficients between SSS and SSH-OBP In this study, the variations and trends for the period from 1979-2012 (1970-2001 as water cycle and biogeochemistry. anomalies suggest that SSS anomalies in tropospheric humidity (up to 300 for ERA-40). are sufficiently sensitive to small variation Satellite measurements of sea hPa) over China are analyzed using a in SSH-OBP anomalies that satellite Results suggest that the PW biases in surface salinity (SSS) provide good newly homogenized radiosonde dataset. SSH-OBP anomalies can be used to the reanalyses are within ~20% for most spatiotemporal sampling to monitor There are, however, many spurious evaluate the quality of satellite SSS. of northern and eastern China, but the Arctic Ocean freshwater changes. changes and discontinuities in the reanalyses underestimate the observed However, the paucity of in-situ salinity This offers a vicarious calibration raw radiosonde records resulting from PW by 20%–40% over western China, observations in the Arctic Ocean poses approach for satellite SSS, allowing us changes in instruments, observational and by ~60% over the southwestern a challenge to evaluate the quality of to examine the signal-to-noise ratio of practice, processing procedures, station Tibetan Plateau. The newer-generation satellite SSS. satellite SSS in the Arctic Ocean and the relocations, and other issues. Recently, reanalyses (e.g., JRA25, JRA55, CFSR feasibility of using current satellite SSS to the daily humidity records radiosonde and ERA-Interim) have smaller root- study Arctic-Ocean freshwater changes. mean-square error (RMSE) than the

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 133 Section 5 older-generation ones (NCEP/NCAR fatalities. Here we analyze first various Technology, Bogor Agricultural vulnerability scores ranged from 0.38 to NCEP/DOE and ERA-40). Most of the observational datasets to assess the University), Alan Koropitan (Department 1.55 where Wangi-wangi, Kaledupa, and reanalyses reproduce well the observed spatio-temporal characteristics of of Marine Science and Technology, Tomia were marginally more vulnerable PW climatology and interannual precipitation, and various large-scale Bogor Agricultural University) than Binongko. The comparisons may variations over China. atmospheric variables from ECMWF lead to better management strategy reanalyses products (era-interim), mass Coral reefs important existences are to deal with a climate disturbance that However, few reanalyses capture the and energy products derived from era- mostly threatened by climate change, focused on the more vulnerable island. observed long-term PW changes, interim atmospheric variables to assess and how vulnerable these reefs to climate primarily because they show spurious the potential influence. Wet condition is change are what we want to know wet biases before about 2002. This prevailed in Western Sahel with severe through this research. Through this study Combination of WRF and ANN deficiency results mainly from the wet condition in central Sahel during July we try to develop and test a methodology Model for predicting cloudburst discontinuities contained in reanalysis to September 2012. Strong TEJ above to assess the ecological vulnerability of RH fields in the mid-lower troposphere Author Abhishek Sharma normal is observed in summer 2012, with coral reef communities focused on small due to the wet bias in older radiosonde None strong divergence anomalies persisted scale in Wakatobi coral reef systems. Affiliation records that are assimilated into the through August 2012. Vulnerability is a combination of Co-authors reanalyses. Thus, more efforts are Abhishek Sharma 1, Dr. Kamal Jain 1 exposure, sensitivity, and the capacity needed to remove spurious changes A dipole flow is observed at AEJ level. (Department of Civil Engineering, to adapt. Exposure was estimated using in input data for future long-term an negative anomalie of Latent energy Indian Institute of Technology Roorkee, an existing spatial model, sensitivity reanlayses. tendency is observed in the Sahel while Roorkee 1) doing a mean from june to september, was estimated using two indicators: suggesting favourable condition for the susceptibility of the coral and Himalayan states of India such as Characteristics of wet West precipitations enhancement. A positive susceptibility of the fish, and adaptive Himachal Pradesh and Uttarakhand African summer precipitation of anomalie of total energy tendency is also capacity was developed based on are prone to cloudbursts, landslides 2012: Large-scale atmospheric observed in most part of sahel and is hard coral cover, coral size distribution, and other catastrophic events due to flow, mass and energy budgets related to convection. coral richness, fish biomass, herbivore its geographical structure. Severity of diversity, and herbivore grazing relative to perspective. these events has a strong correlation algal production. with the orographic precipitation. On 8th Samo DIATTA Climate Change Vulnerability Author The three facets of ecological August 2015 between 00 to 06 hr UTC, Affiliation University Assane Seck of Coral Reef Ecosystem vulnerability (exposure, sensitivity and heavy and continuous rainfall lead to a of Ziguinchor in Wakatobi Water recovery potential) were not strongly cloudburst event over Mandi district of Himachal Pradesh. Co-authors Author Muhammad Taufik Taufik correlated, suggesting these different S. Diatta (Laboratoire d’océanographie components of ecological resilience Affiliation Bogor Agricultural The interaction of extensive monsoon are not related (Pearson correlation des Sciences de l’Environnement et du University flow and the elevated terrain makes the Climat-LOSEC), D. Sambou (LOSEC), coefficients: exposure to sensitivity, r = high rainfall event persistent as well as M. Camara (LOSEC), B. Sow (LOSEC), Co-authors 0.19, exposure to recovery potential, r = Muhammad Taufik (Department of Marine more sever over the area which leads to M. L. Mbaye (LOSEC). –0.46, sensitivity to recovery potential, flood, landslide and loss of many lives. Science and Technology, Bogor r = -0.48). Among all observed island, Severe floods have characterized West Agricultural University), Hawis Madduppa Binongko Island is the least sensitive African summer of 2012 with nearly 3 (Department of Marine Science and island (F = 8.84, P = 0.006). Site-specific million people affected and caused 300

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 134 Section 5

In the present study rainfall has been all calendar months with the possible taken as the criteria for predicting Comparing traditional exception of August, for the period of the Comparison of East Asian the intensity and location of Mandi climatological records with regional reanalysis (1995-2014). Monsoon using ERA, NCEP/ cloudburst using ANN approach, reanalysis time series over The correlation coefficients between NCAR, JRA reanalysis data Input data to which was obtained by Germany COSMO-REA6 and traditional monthly performing numerical simulation using Author Rongshuo Cai means from gridded station data the Weather Research and Forecasting Author Andrea Kaiser-Weiss Affiliation Third Institute of are higher than 0.97 for most areas. (WRF) model. WRF model was Oceanography, State Affiliation Deutscher Wetterdienst Differences between the regional configured with spatial resolution of 7km Oceanic Administration Co-authors reanalysis and the gridded station data over three sites of cloudburst that is of China M Borsche (DWD), D Niermann (DWD), appear at Northern Germany, likely Uttarkashi (30.7268 N, 78.4354 E), Leh F Kaspar (DWD) because of the lack of data coverage in Co-authors (34.1526 N, 77.5771 E) and Mandi (31.706 the traditional method. More differences Rongshuo Cai (Third Institute of N, 76.93 E). Traditionally, gridded station data are become apparent when reducing area Oceanography, State Oceanic Different physics option and convection the basis to estimate climatological time size. Administration of China), Hongjian Tan parameter with single domain for series of, e.g., the development of mean (Third Institute of Oceanography, State Discrepancies could be caused by Uttarkashi, Leh and multiple nested 2 temperature over Germany. Oceanic Administration of China) various reasons, for instance by local way domain for Mandi has been used to Here we compare this time series influences on the station observations, Based on the long time series and high- best simulate the event. Three different against the one derived from the regional or by a lack of the reanalyses to capture resolution reanalysis data of wind field Neural network training was done using reanalysis COSMO-REA6 as well as the processes observed at the stations. such as ERA (merged from ERA-40 and MATLAB with input data of Uttarkashi against the global reanalysis ERA-Interim. Here we show our results in attempting ERA-interim), NCEP/NCAR and JRR- having 11 inputs and 89 samples, Leh We focus on temperature observations to distinguish between these options and 55, the characteristics of spatial and having 11 input and 991 samples, Mandi performed 2m above ground. There are the implications for trend analysis over temporal variations of East Asia monsoon having 11 inputs and 85 samples using discrepancies in the statistical properties Germany. (EAM) over Eastern Asia and the adjacent Feed Forward Neural Network with Back on scales from the hourly scale to the offshore area are analyzed using Propagation algorithm. decadal scale. For the whole of Germany, empirical orthogonal function (EOF). Hyperbolic tangent sigmoid function the COSMO-REA6 annual cycle matches The statistically analysis results indicate at hidden layer and linear function at the traditionally derived one, allowing for that climatological mean wind fields output layer was taken as the activated a bias with annual cycle which is well- at 925 hPa are of very similar features function for training the three networks. known for COSMO model. in winter and summer using all three Number of hidden layers was decided The year-to-year variability is higher kinds of reanalysis data. The leading using Kolmogorov’s theorem. Prediction than the bias. Both reanalysis data EOF modes of EAM wind fields at 925 was done at Mandi using three trained and traditional data track the annual hPa in winter (summer) over eastern neural networks. Results are shown as anomalies. For trend applications it is China and East China Sea could display the observed and predicted rainfall at 6hr of interest whether the bias is constant basic variation patterns of southward time step. over the decades. This can be confirmed (northward) meridional winds on inter- for the annual mean over Germany and decadal timescale; however, they also show some different features over middle (southern) China and South China Sea.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 135 Section 5

After comparing their EOF (EAM) temproal The lateral spread of OGWs can reduce precipitation. This article deals on the charicteristics (principal components, the local wave amplitude with height, Critical analysis of climatic critical analysis of Climatic Trends and PCs) and the spatial differences between thereby giving rise to wave breaking and trends and forecast of irrigation Irrigation Schedule for maize. the leading EOF modes and the previous hence OGWD at higher altitudes. Using calendar for maize from global Monitoring conducted in the period observed results over middle (southern) the Gaussian beam approximation (GBA) circulation model in the Ruzizi 1965-1995 provided data retrieved from China, the JRA-55 reanalysis that is approach, a new OGWD parameterization the meteorological station. The data were suggested available for a much longer scheme is proposed which explicitly river area in Democratic analyzed and then the selected models period and newer are therefore to deals with the horizontal propagation of Republic of the Congo were used to predict the situation until investigate the variations of EAM in our OGWs. This new scheme is compared Author Romain Ntole 2045. Hence we can assert that the recent study. Finally, the proposals on with the traditional scheme by examining Affiliation African youth for change in the distribution of precipitation atmosheperic and the related reanalysis the OGWD in the stratosphere of entrepreunership and has a direct effect on the choice of data products are also promoted. Northern Hemisphere during 2011-2016, development planting date. The exhaustion will using the ERA-interim reanalysis data decrease because in 2045 we will have a produced at the European Center for Co-authors large amount of precipitation with a more Comparison of two Medium-Range Weather Forecasts Mutalemba Ntole Romain1,*, Muhigwa or less balanced distribution. parameterization schemes of (ECMWF). jean Berckmans2, Katcho katcho orographic gravity wave drag karume3, Mukengere bagula This can be explained by the fact that the In summer, the OGWD obtained from Espoir41Engineering in Agricultural, effects of climate change on agriculture using the ERA-Interim reanalysis the traditional scheme is generally Université Evangélique en Afrique, DR result in a change in the distribution of confined in the lower stratosphere north Author Xin Xu Congo2Department of Biology, Faculty of precipitation causing changes in the of 30°N. In the new scheme the mid- Affiliation Nanjing University Sciences, Bukavu Official University, DR cropping calendar. Climate change will latitude (about 30~60°N) OGWD is also Congo3Dean of the faculty of agriculture cause difficulties for farmers to heir Co-authors mainly located in the lower stratosphere, and Environmental sciences, Université agricultural practices, as time indicators Xin Xu (School of Atmospheric Sciences, while at high latitudes notable OGWD Evangélique en Afrique, DR Congo4CAES relating to the seasons will lose all Nanjing University), Yuan Wang (School is found within a deep column of the Makerere University and Université reference of Atmospheric Sciences, Nanjing stratosphere. In winter, both the new and University) Evangélique en Afrique, Faculty of old parameterization schemes produce Agriculture and Environmental sciences Developed in early 1980s, the OGWD in the whole stratosphere, Soil Management and Geoinformatic parameterization of orographic gravity especially in the upper stratosphere of Unit, DR Congo*Corresponding Author: wave drag (OGWD) is now implemented high latitudes. [email protected] in nearly all the state-of-the-art general To sum up, the new parameterization In the context of global climate change, circulation models (GCMs) and chemistry scheme tends to give smaller OGWD it is necessary to evaluate the changes climate models (CCMs). However, current in the lower stratosphere but larger generated on global and fine scales, OGWD parameterization schemes only OGWD in the mid-upper stratosphere. such as maize agro-system in the Ruzizi consider the vertical propagation of The difference between them mainly river area in Democratic Republic of orographic gravity waves (OGWs), while occurs over the Tibet Plateau, the Rocky the Congo, particularly in terms of in reality these waves propagate both Mountain, and the Greenland. vertically and horizontally. frequencies of thermal extremes and

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 136 Section 5

The thermal pattern indicates the These forecasts were used to produce Dynamic structure of western presence of a thermal low to the west ECMWF probabilistic forecasts the ensemble operational seasonal disturbances affecting North of the contour low to aid development. for near-real-time monitoring predictions and constitute models inputs. India during winter Increase in specific humidity is of drought in the trans-boundary Short (1-month) and medium (3 and noticed 10-12° to the east of the low. Prut River Basin 7-month) range WF were retrieved. Author N VINOD SANKAR Convergence is observed at the lower The reliability of the forecast ensemble Sankar levels up to 500 hPa with maximum Author Vera Potopova will be determined by validation using Affiliation CUSAT values at 700 hPa and divergence is Affiliation Czech University of Life historical sets of hindcasts. The stronger at higher levels with maximum Co-authors Sciences Prague, inherent uncertainty of seasonal WF values at 300 hPa. Upward velocity N Vinod Sankar 1* (CUSAT), CA Babu 2* Department Agroecology was quantified by issuing probability maxima were observed between 400- (CUSAT) and Biometeorol statements about future observable 500 hPa. Positive vorticity advection, Co-authors outcomes based on current and past An attempt is made to study dynamic increases with height and the region Vera Potopová, Department of forecasts (hindcasts) and observations. structure of western disturbance of moderate to rather heavy rainfall is Agroecology and Biometeorology/Czech The WF will be withdrawn from ECMWF affecting north India during winter. found at the region of positive vorticity University of Life Sciences Prague, throughout the project in order to update The analysis was carried out utilising advection. Czech Republic, [email protected] the information provided by the models daily rainfall data from IMD, wind, It is found that warm air advection of the namely in terms of irrigation management temperature and humidity profiles from order of more than 40 K s-1 takes place The aim of this study is to validate a during the growing seasons. FNL and ECMWF. Ten cases of western at the lower levels. The magnitude of probabilistic methodology from the disturbances that produced more than potential vorticity is one order higher at ECMWF (Centre for Medium-Range 35 mm rainfall over North India were the lower level than at the higher level of Weather Forecasts) for near-real-time Effect of wind forcing on oil spill identified using the daily rainfall data of the troposphere, however, the gradient drought monitoring and forecasting simulation in the Persian Gulf the IMD. to optimization of crop irrigation is more prominent at the higher levels. Author Sahar Mokhtari The vorticity, divergence and vertical With the approach of the WD, a positive management in the Prut River catchment. Affiliation ports and maritime velocity, vorticity advection, thermal potential vorticity anomaly of the order of The trans-boundary Prut River Basin organization (I.R.Iran) advection, potential vorticity and 5 X 10-5 K m2kg-1s-1 is observed at the is one of the most drought vulnerable potential vorticity anomaly were lower levels. areas in the Republic of Moldova, Co-authors evaluated from the reanalysis data Romania and Ukraine due to high water Sahar Mokhtari (Ports and Maritime products. It was found that an exploitation. This paper presents the Organization of I.R.Iran), Ji´rí Kadlec anticyclonic flow and dry weather is research undertaken within the project Oil pollution is a serious environmental interrupted when western disturbances IMDROFLOOD (http://imdroflood. problem with critical impacts on marine affect North India. Lower level circulation meteoromania.ro). and coastal habitats, wildlife, fisheries and mid and upper tropospheric troughs Seasonal daily weather forecast (WF) of and human activities (Allan et al., 2012; describe the wind flow pattern. The maximum and minimum temperatures Fattal et al., 2010; Carson et al., 1992). contour low is seen extending to 300 hPa and precipitation from the ECMWF For preventing future oil spill disasters level, with a westward slope with height. were collected and downscaled for the and to develop optimal planning and different locations from upstream to management strategies in response to downstream of the Prut River Basin. oil spill events, an environmental risk

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 137 Section 5 assessment with capacity to support The main goal is to test the effect of Andes, which directly influence the be used to investigate the spatial and decision making is needed (Fabbri, 1998; different types of wind forcing (constant rates of snowfall, rainfall, evaporation temporal distribution of snowfall over Assilzadeh and Gao, 2010). This requires wind, spatially variable wind, time and condensation. The sensitivity region of high topography. identifying and prioritizing areas in the variable wind) and wind input data on experiments were divided in a series of coastal zone where there is a need for an the simulated oil spill trajectory, and seven MP experiments. allocation of resources, while minimizing test which data inputs provide the best Estimation of hourly and daily Initial atmospheric and land surface the risks and costs (Keeney, 1982; Mata oil spill simulation results. The aim is clearness indices and diffuse conditions (IC), have been provided 0.750 and Corchado, 2009). to find the best wind inputs for optimal fraction, over Port Harcourt and x 0.750 ERA-interim (Dee et al. 2011) prediction of oil spills in the Persian Gulf. Many studies develop methods, tools, web site http://apps.ecmwf.int/datasets/ Kano Nigeria using NCEP/NCAR We will use the observed Mina Al-Ahmadi and decision support systems to identify data/interim-full-daily/levtype=sfc/, satellite data oil spill event for the Mike 21/3 model potential oil spill sites, support oil spill available every 6 hours. Snowfall events verification. The calibrated model will be Author Vincent Omole risk management, and reduce the were simulated with WRF using two at the core of a decision support system College of Education/ adverse effect of oil spills (Mokhtari et al., grids with 9 km (120x150) and 3 km Affiliation for oil spill management and coastal area University 2015; Ko and Chang, 2010; Lehikoinen et (246x280) horizontal spacing and vertical protection in the Persian Gulf. al., 2012; Jolma et al., 2014; Juntunen et levels (1000 hPa to 50 hPa). The WSM3, Co-authors al., 2005). Soltanpour et al. (2013) studied Morrison and WDM5 schemes produce B. Adeyemi,(Federai University of the key factors influencing the movement Era-interim analysis in the more snowfall than WSM6, Goddard, Technology Akure.Nigeria), O.V Omole, of oil spill in the Persian Gulf, and found different microphysics schemes WDM6 and NSSL schemes. WSM3 (College of education ikere Nkiti Nigeria),O Oloniyo, (federal University that wind was the most important factors. of the WRF model for a snowfalls scheme reaching 360 mm (3,4,5 June In marine environment the wind forcing 2016). of Technology Akure) data is obtained from surface (synoptic) in the Andes In general, simulations with the various In this study, estimation of clearness station, satellite observation, or numerical Alcimoni CominComin Author MP schemes of WRF have been properly index (KT = H/H0) and diffuse fraction atmospheric model. Model assimilation Affiliation Federal University of represented, the snowfall occurs in the (KD = HD/H) were calculated using techniques are used to improve the wind Vicosa same regions of the convective cells available satellite data obtained from model forecast. According to Jones pass and of the precipitation estimated National Centre for Environmental (1999), meteorological forecasts of wind Co-authors by TRMM. This shows that the WRF can Prediction (NCEP) and National Centre from numerical model can be used as A. Comin (Federal University of Vicosa), be a useful tool in the simulation of such for Atmospheric Research (NCAR) data input to oil spill simulation with same F. Justino (Federal University of Vicosa), events, especially in a difficult access base covering a period of 10 Years accuracy as field wind observations. (Federal University of Vicosa), region such as the mountain range. (2005–2014) for Port Harcourt and Kano Temporal variations in wind were more V. Schumacher (Federal University Simulation WRF aims to fill this gap, stations which are Coaster and Sahel important than spatial variations, and of Vicosa), A. Silva (Federal University because the networks of meteorological regions respectively. Direct solar data a high temporal resolution of the wind of Vicosa), Noeli Leonardo (Federal stations and atmospheric soundings are and diffuse solar data collected were should be used In the use of oil spill University of Vicosa) very scarce. added to give the Global solar radiation. model for contingency planning and This study analyzes the impact management, a stochastic simulation of different cloud microphysical In addition, rainfall accumulation analysis The clearness index (KT) which is with multiple events is often used (Eliot et parameterizations (MP) of the WRF at the Portillo weather station (32.842S the ratio of the global solar radiation al. 2014). model associated with extreme snowfall and 70.118W), matches our simulations obtained at the surface to the total solar events on complex terrain of the central values. Therefore, ERA-interim as IC can radiation at the top of the atmosphere

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 138 Section 5 was obtained. The diffuse fraction A large number of weather driven different time scale but also at different (KD) was obtained from the ratio of the extreme events has occurred in the last Evaluation of systematic errors weather conditions i.e. pre-monsoon, diffuse solar radiation incident on the decade, namely in the Iberian Peninsula, in WRF-ARW Boundary layer monsoon, heavy rainfall situations. horizontal level of earth surface (HD) to that has been struck by record breaking parameterization schemes over In addition, efforts will be made to the global solar radiation that incident extreme events with unprecedented Indian region. identify possible major sources, on the surface level (H). The computed socioeconomic impacts. Outstanding quantification, growth of these errors clearness index value were used to costly windstorms such as Klaus in 2009 Author Sandeep Pattnaik associated with different (dominating) characterize the sky conditions into clear (Liberato et al. 2011), Xynthia in 2010 Affiliation IIT Bhubaneswar dynamical and thermodynamical skies and overcast skies. Port Harcourt (Liberato et al. 2013) or Gong in 2013 Co-authors mechanisms and model ability to with low clearness index indicated low (Liberato 2014) experienced explosive Sandeep Pattnaik (Assistant Prof.), replicate those in a prognostic manner. global solar radiation while Kano with development over Eastern North Atlantic, Vivekananad Hazara (Research Scholar), The results presented will examine not large clearness index indicated high making landfall on the Iberian Peninsula. Deepika Rai (Research Scholar) Anshul only the fundamental parameters such global solar radiation. The implications of Some of these storms had their genesis Sisodiya (Research Scholar) as wind, temperature, moisture, rainfall these results on the effective utilization of on a region characterized by warm and but also important diagnostic parameters solar energy are discussed. The results moist air associated with anomalously A series of numerical experiments are to highlight how these are getting also serve as very useful for solar energy high sea surface temperatures (SSTs), carried out at 9 and 27km horizontal modulated to facilitate systematic error collectors in designing and estimation according to ERA-Interim reanalysis data. resolution over Indian region using WRF- growth in the model forecast. of solar application systems. Keywords: The recent availability of the high- ARW model with four different boundary Clearness Index, Diffuse Fraction, Global resolution 1/12° Physical IBI reanalysis layer parameterization schemes namely Solar Radiation product covering the altimetric decade YSU, MYNN, MRF and ACM2. The Evaluation of the impact of (2002-2014), for the Atlantic-Iberian experiments are carried from May 15 climate change on coffee Evaluation of anomalous SST in Biscay Irish- Ocean – providing to September 30 for two contrasting cultivation in the upper basin of monsoon years i.e. 2013 (normal) and the explosive development of hourly mean values of surface fields the river Sisa – Provinces of such as SST – is an opportunity for 2014 (deficit). Each simulation has been windstorms over Eastern North carried out from daily initial condition Lamas (Alonso De Alvarado a better assessment of the evolution District) and El Dorado (San Atlantic and variability of warming SSTs and starting from May 15 up to 96hours (day4) forecast lead time. Martin De Alao District) – San Author Margarida L. R. Liberato potentially enhanced latent heat releases during the explosive development of Martín Region Affiliation Universidade de Trás-os- The main objective of this work is Montes e Alto Douro most extreme storms. Finally, a better to understand and characterize the Author Fabiola Guzman Vidal knowledge of storms dynamics will systematic errors existing in the WRF- Co-authors Affiliation Centro de Investigaciones contribute to improved windstorm risk ARW model with reference to boundary Margarida L. R. Liberato ((1) Instituto de Zonas Aridas assessment for the Iberian Peninsula and layer parameterization at different time Dom Luiz, Faculdade de Ciências, thus to better coastal planning strategies scales i.e. daily, monthly and seasonally. Co-authors Universidade de Lisboa, 1749-016 and definition of adaptation and Further, efforts will be made to validate Fabiola Guzman Vidal (CIZA-UNALM), Lisboa, Portugal and (2) Escola de mitigation policies. Acknowledgements: these forecast with multiple benchmark Juan Torres Guevara (CIZA-UNALM), Ciências e Tecnologia, Universidade de This work is supported by FCT – project reanalysis data sets such as ERA-Interim, Nicolas Ibañez Blancas (CIZA-UNALM), Trás-os-Montes e Alto Douro, UTAD, UID/GEO/50019/2013 – Instituto Dom NCEP-NCAR reanalysis to elucidate rate Aracelly Mallma Carrera (CIZA-UNALM) Vila Real, Portugal. [email protected]) Luiz. of systematic errors growth not only at

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 139 Section 5

Predictions about the impacts of climate temperature for this period of time and 2008–2013 were discussed in the study. On the island of Orkney, for example, change on the cultivation of coffee the increase of suitable areas for this ECMWF Reanalyse data ERA-Interim is there are implications for the field of in Latin America indicate substantial altitude range is 980.1 has (14.94%). used for different vertical heights, and heritage conservation, with World contractions in its performance due to The change in weather conditions in the meteorological variables of ERA- Heritage sites such as the Neolithic the decrease of flowering and the fall the upper basin of the river Sisa to the Interim are downscaled on the station of settlement of Skara Brae at particular risk of the grains, as well as the increase year 2050 would favour the expansion of Kale – Demre. from increased erosion. Recent episodes in pests and diseases. This research coffee crop fields, causing the change of of storminess in the UK invite speculation The vertical thermodynamic structure studied the effects of climate change use of land (deforestation). as to whether a shift is underway towards of vortexes are analysed by diagrams in the coffee crops in the high basin more extreme weather. However, the and vertical indexes of Plymouth State of the river Sisa. The perception of complex spatial dimensions of the Weather Center. The acceptability of farmers gathered in workshops and Evaluation of Waterspouts by regional storm climate necessitate more the Szilagyi Waterspout Index for four etnometoreologicals surveys about the Szilagyi Waterspout Nomogram localised study. extreme cases are computed and the effect of climate change in the districts and Triangle Diagram availability of waterspout predictions This research examines the role that of San Martín de Alao (Prov. El Dorado) Author Sevinc A. Sirdas have been examined in the study. In large-scale circulation plays in local and Alonso de Alvarado Roque (Prov. addition, a triangle diagram was created storminess for the North Atlantic islands Lamas), matches with the results of the Affiliation Istanbul Technical for the waterspout cases in the Antalya of Orkney and Shetland. Automatic Lamb climatic data, showing a tendency with University region for period of 2000 and 2012, which classification is applied to twentieth increasing temperature (minimum and Co-authors is composed of Sweat Index, relative century reanalysis data to typify large maximum), decreasing precipitation and Sirdas, S. A., Özmen, I., Yavuz, V.Y., humidity and 850mb wind speed. Key scale circulation patterns and calculate changes in the frequency of rains, due to Kaya, S. and Aydın, M words: Climate Change, Extreme, Vortex, measures of storminess, which are the increase of the intensity of rain and Waterspout, Szilagyi Waterspout Index, then validated using observations from change in seasonality. Climate change impacts on extreme and rare weather events are much more Triangle Diagram, Demre meteorological stations on the islands, A result of the climate model CGCM 2.0 obvious so that many scientific studies obtained through the UK Met Office. according to the B2A1 scenario, revealed have been focused on worldwide. The This research uses the ERA-20C (1900- an increase in the maximum temperature Exploring storminess on North connection between the formation of 2010) reanalysis dataset produced by for the year 2050 of 1.0 to 1.2 ° C and Atlantic islands using reanalysis waterspouts that are considered as the European Centre for Medium-Range the minimum temperature for this year data rare event for Turkey and the climate Weather Forecast. Daily mean sea level of 1.7 to 1.8 C °. For the total annual change has been a matter of curiosity. Author Aideen Foley pressure (MSLP) data was obtained precipitation, there is an intensification The vortex incident and waterspout have at 0.125° x 0.125° resolution, to which of 24 to 61 mm, which might be the Affiliation Birkbeck, University of been observed 260 times in the period the weather classification method frequency variability. The MaxEnt London between 1997 and 2015 at Turkey, and was applied. By characterising the algorithm shows that there is a higher Co-authors the most of them were observed in relationship between large-scale climate expansion of areas of coffee cultivation in A.M. Foley (Birkbeck, University the coast and lakes of Antalya. In this trends and regional weather patterns, this the year 2050. of London) study, the data sets of ground base research adds to our understanding of stations and ERA- Interim are analysed The new optimum altitude range would Storm events impact on the built and contemporary changes in storminess on for four extreme waterspout cases in be from 1500 to 2500 msnm, which is natural environment of North Atlantic Kale – Demre, Antalya station which consistent with the prediction of the islands, with a range of environmental, were observed at the period between increase of maximum and minimum economic and social effects.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 140 Section 5

North Atlantic islands, and can thus aid The daily global active fire from the be mitigated. From a total of fifty years climate of extreme waves. Features of in anticipating and adapting to further, Satellite Terra/MODIS was used data for twenty seven locations across extreme waves are here predicted in a future change. to validate the analyses. It was Nigeria, forty years data were deployed in probabilistic sense, i.e., the maximum demonstrated that under current climate various artificial neural networks models crest and crest-to-through wave heights and vegetation conditions the PFRI is to forecast for ten years of rainfall. The in a sea state are treated as random Fire Susceptibilty under different able to reproduce the principal fire risk results were validated using root mean variables, of which we estimate the atmospheric conditions areas which are concentrated in the square (RMSE), accuracy and correlation probability distributions and expected Author Alex Santos da Silva Sahelian region and in northern of South coefficient, R. values, at single points (time extremes) America from December to March, in and over areas (space-time-extremes). Federal University of The feedforward neural networks Affiliation subtropical Africa and Midwest region of Vicosa model of five inputs (latitude, longitude, In particular, the Tayfun nonlinear Brazil from July to October. Co-authors elevation, month and year) had the best model is considered for the probability A. Silva (Federal University of Vicosa), In almost all continents the efficiency results with values of 0.86 and 6.68 for and expected value of maximum crest F. Justino (Federal University of Vicosa), of the model was approximately 70% in R and RMSE respectively. And given heights, while for the maximum crest- N. Leonardo (Federal University of presenting occurrences over 10 fires in the accuracy of 93.32%, the networks to-through wave heights expected Vicosa), V. Schumacher (Federal the grid cell. The PFRI reproduces areas can effectively be used to forecast for values are estimated combining the University of Vicosa), A. Comin (Federal with high fire activity and those ones other locations in Nigeria. Tools such Tayfun nonlinear model and the Quasi- University of Vicosa) which present atmospheric patterns as neural networks that have the ability Determinism theory. totally distinct from the equatorial zone, to understand the patterns in any given For our purposes, we use the directional Based on Era-Interim Reanalysis and indicating that this index is an useful tool set of data are highly recommend for wave spectra produced by ERA-Interim GPCP (Global Precipitation Climatology for forecasting fire occurrence worldwide forecasting and studies of trends. over the entire global oceans, including Project) datasets we analyzed the because it is based on regionally marginal and enclosed seas (e.g., vulnerability to wildfire occurrence from vegetation and climate factors. Mediterranean Sea), with 1°x1° spatial 2001 to 2015. The investigation applies Global climate of extreme ocean and 6-hour temporal resolutions. The a Potential Fire Risk Index (PFRI) which waves from ERA-Interim spectral parameters provide parameters runs a roughly exponential function Forecasting Rainfall in Nigeria Author Francesco Barbariol of the probability distributions and adjusted for three atmospheric layers Using Neural Networks Affiliation ISMAR-CNR expected values of extreme waves. of the Haines Index (HI). The PFRI is set Author Nsikan Obot with eighteen classes of vegetation as Co-authors An analysis of the directional spectrum Affiliation University of Lagos boundary condition extracted from the F. Barbariol (ISMAR-CNR, Italy), parameters and extreme waves over International Geosphere and Biosphere Co-authors A. Benetazzo (ISMAR-CNR, Italy), the ERA-Interim reanalysed period Program. N. Obot (Department of Physics, L. Cavaleri (ISMAR-CNR, Italy), M. Sclavo (1979-2016) is conducted in order to: University of Lagos) and I. Humphrey (ISMAR-CNR, Italy), JR. Bidlot (ECMWF, (i) highlight regions of the oceans that This is formulated on the principle that (Department of Physics, University of UK), P. Janssen (ECMWF, UK) are more prone to the development the vegetation fire risk increases with Lagos) of extreme waves, (ii) assess the the increasing duration of dry periods, We present an application of the ERA- presence of climatological trends in type and natural cycle of vegetation Rainfall is about the most complex Interim dataset that we use for the global extreme waves, taken into account the phenology, maximum temperature and parameter in meteorological studies analysis of extreme ocean waves. The 1991 discontinuity in significant wave relative humidity of the air. and if it is adequately forecasted, the main goal is to assess, for the first time, height statistics due to the beginning of problematic fallouts of excessive rain can the global signature of the multi-decadal altimeter assimilation.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 141 Section 5

sources will organize an innovative mesh Some weather variables in the GREENTOP – Gamification of network of independent processing units High Resolution Composite atmospheric levels show clear patterns cRowdcomputing to ENhance providing green processing power. Maps for Extreme Rainfall in to be used as a guidance to predict extreme rainfall events. The composite EarTh Observation data Big Data of Earth Observation is split into Indonesia maps are able to explain the atmospheric Processing parts individually processed, constantly Author Heri Kuswanto conditions at one to five days prior to the updating the Earth view from space. Author Sorin POP Affiliation Institut Teknologi Sepuluh occurrence of the events in Indonesia, Processed data will be publicly available Nopember (ITS) which has never been explored so far. Affiliation Indeco Soft for viewing, while thematic downloads Co-authors will be charged. Potential customers are Co-authors SP Sorin POP (Indeco Soft), Gabriel Environment NGO’s, local authorities, Heri Kuswanto (Research Center for High resolution regional ZETE (Indeco Soft), Ana Maria POP small and medium sized business in the Earth, Disaster and Climate Change- reanalysis: a tool for the Institut Teknologi Sepuluh Nopember- (Indeco Soft), Ciprian GHIS, E (Indeco forestry and agriculture domains, while identification of extreme wind Soft) cooperation with universities in imagery Indonesia, Kiky Ferawati (Institut research projects is also envisaged. The Teknologi Sepuluh Nopember-Indonesia) surges in the German Bight The European Space Agency provides collaboration with startup communities Climate change has increased the Author Natacha Fery free access to great amounts of data through preferential data access and intensity of extreme weather events Affiliation Deutscher Wetterdienst from its space missions. Processing it accessible fees has the purpose of in Indonesia. One of the strategies for applications in forestry, land cover, boosting further innovation and creativity. Co-authors land use, precision agriculture and other to minimize the risk is by developing N. Fery (DWD), B. Tinz (DWD), A. Ganske fields requires huge capabilities. Through Data will be processed using well- a forecasting tool enable to provide (BSH), A. Andersson (DWD), L. Gates gamification, a community of enthusiasts known algorithms for high resolution an accurate prediction about the (DWD) is encouraged to share their computing multispectral imagery (Sentinel2) and occurrence of extreme events. This power to rapidly process small portions multiple instruments data (Sentinel research developed high resolution In the context of global climate change, of imagery. Members can also participate 3). GREENTOP – Gamification of composite maps designed specifically interest in the study of very severe actively in validating data manually, cRowdcomputing to ENhance EarTh for extreme rainfall events in Indonesia. storm surges and their impacts on the providing a human verification of the Observation data Processing encourages High resolution refers to the grid space of southern North Sea and more particularly computer processed information. internet users to support ESA’s initiative the reanalysis dataset used to create the in the German Bight has increased over of distributing free spatial data. map. ERA-Interim reanalysis dataset has the last decades. In the framework of User involvement, both for automated been chosen as the the input. the research project EXTREMENESS, processing and manual validation will Further applications include tacking input funded by the German Federal Ministry be encouraged through a gamification from IoT devices for enhancing analysis The composite maps provide information of Education and Research, two methods process (virtual badges, eCards, algorithms. This work is the object of a about the dynamic pattern of some are implemented to identify extreme premium access to data, gifts of feasibility study financed by the European weather variables in atmospheric (upper) wind surges likely to cause significant independent processing units – IoT Union’s Horizon 2020 research and levels as well as information about damages along the coast of the German devices). The Internet of Things, through innovation programme – SME Instrument, active zones associated to the events. Bight. small computing modules that process under grant agreement No. 773660 and Bootstrap resampling approcch has been images using energy from renewable will be complete in October 2017. applied to validate the map with certain To achieve this goal, high resolution degree of significant levels. reanalysis from the regional model COSMO-REA6 (Deutscher Wetterdienst, University of Bonn) is evaluated

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 142 Section 5 by means of recent and historic Korea, Severe Storm Research Center, as Global Final Analysis (FNL) data. Peatlands are characterized by high meteorological observations. A statistical Ewha Womans University, Seoul, Spatial interpolation of rain gauge data soil moisture contents and hydrological wind surge model based on wind speed, Republic of Korea, Center for Climate/ was done by applying inverse distance dynamics that differ greatly from those in wind direction and sea level pressure is Environmental Climate Prediction weighting interpolation method to bring biomes on mineral soils. In combination optimized for extreme events that are Research, Ewha Womans University, observation to the model grid spacing. with peatland-specific vegetation detected in the dataset. Seoul, Republic of Korea, Department of Two parameters; convective adjustment characteristics, this leads to distinct Environmental Science and Engineering, time and humidity reference profile factor energy and water fluxes across the soil- A second method consists of evaluating Ewha Womans University, Seoul, of the Betts-Miller-Janjic convective vegetation-atmosphere interface over the so-called effective wind and its Republic of Korea), X. Yu (Center for parameterization scheme have been these environments. Covering 3% of the extremes. The effective wind is the result Climate/Environmental Climate Prediction optimized. Results showed that the global land surface, peatlands can be of the projection of the real wind onto Research, Ewha Womans University, optimized forecast have improved a regionally dominant biome, and thus that wind direction, for which the impact Seoul, Republic of Korea, Tropical Marine slightly and the equitable threat score importantly influence the land surface of the wind on the water level is most Science Institute, National University values were low which made the forecast boundary conditions for weather and effective. The present study highlights of Singapore, Singapore) slightly better than a random forecast. climate simulations. However, modeling the advantages of using these methods of peatland hydrology is a challenging instead of the often used high percentile Over decades now, Quantitative task. calculation for the identification of Precipitation Forecast (QPF) have seen Improving water level and soil severe surges. The accuracy of the lot of progress in it accuracy through moisture over peatlands in a In these shallow-groundwater systems, high resolution reanalysis is as also the use of Numerical Weather Prediction global land modeling system soil moisture of the unsaturated zone, assessed for the storm conditions under (NWP) in many parts of the world. The and consequently the energy and consideration and climate projections demand for accurate weather prediction Author Michel Bechtold water exchange with the atmosphere, are analyzed to provide a range of future has increased over the years which calls Affiliation KU Leuven is closely coupled to water table depth, severe wind surges. which is thus a key variable that must for improving on forecast skill. NWP have Co-authors be adequately modeled. We discuss helped improve on weather prediction. M Bechtold (KU Leuven, Department of the capability of an operational global Earth and Environmental Sciences, Improving on Quantitative This study seek to examine the land surface model to simulate peatland Belgium), GJM De Lannoy (Department Precipitation Forecast over improvement of QPF over Ghana to hydrology. Specifically, we evaluate the of Earth and Environmental Sciences, Ghana using WRF with Genetic determine a better forecast skill of a Catchment land surface model (CLSM) Belgium), D Roose (KU Leuven, heavy rainfall using Weather Research of the NASA Goddard Earth Observing Algorithm Department of Computer Science, and Forecasting (WRF) model with System version 5 (GEOS-5) modeling Scientific Computing Research Group, Author Maureen Abla Ahiataku Micro-Genetic Algorithm (GA) at 9 km and assimilation framework, which is one Belgium), RH Reichle (NASA Goddard Affiliation Ewha Womans University horizontal resolution. GA uses natural of the few global land surface models in selection of parameters for evolution Space Flight Center, Global Modeling Co-authors which water table depth is modeled at all. through global search optimization and Assimilation Office, Greenbelt, M. A. Ahiataku (Department of Climate Maryland, USA), RD Koster (NASA A preliminary analysis of groundwater and Energy Systems Engineering, Ewha method to obtain an optimal parameter values for the forecast. Goddard Space Flight Center, Global levels from the GEOS-5 Modern-Era Womans University, Seoul, Republic of Modeling and Assimilation Office, Retrospective Analysis for Research and Korea), S. K. Park ( Department of Climate The boundary and initial conditions Greenbelt, Maryland, USA) Applications version 2 (MERRA-2) and and Energy Systems Engineering, Ewha were obtained from the National Center other GEOS-5-based land-only products Womans University, Seoul, Republic of for Environmental Prediction (NCEP) show very little differences between

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 143 Section 5 areas with peatlands and those with reanalysis data shows that the westward average technique2 for comparison dominantly mineral soils. In contrast, propagation is not a continuous process, Inter-comparison of ERA- with observation. Indian continent gets observed water table levels show but consists of multiple eddy formation, Interim, MERRA, NNRP high wind during south-west monsoon, strong differences in temporal statistical merging and annihilation during its reanalysis and GFS-ANL analysis a period of four months from June to moments between peatlands and areas westward progression and more over data for Wind Resource September. The monthly mean wind with mineral soils. Therefore, we present there exits asymmetry in its vertical axis speed profiles of reanalysis data an initial attempt to improve the GEOS-5 during its westward propagation. Assessment across India have shown good agreement with CLSM performance over peatlands by observations and with each other. The surface portion of LL dies out near to Author Chinmay Kulkarni updating select parameters based on the western margin (60oE) of the Arabian Affiliation Meteodyn It is found that, all reanalysis monthly improved ancillary data and parameter Sea near to Somali coast. However, the mean values under-estimate the optimization, while keeping the current Co-authors subsurface portion (85 m and below) observation values for most of the cases GEOS-5 CLSM structure as used in Chinmay Kulkarni, Eric Tromeur propagates till to the western coast of though they catch the trend successfully. MERRA-2. the Arabian Sea, touches the coast and Reanalysis data is extensively used in The reanalysis data also captured the reflects back into the equatorial wave Wind Resource Assessment (WRA) to prevailing south-west wind direction Influence of westward guide. produce long-term correction series of observation successfully. However, of measured wind data. A long-term the reanalysis data sets failed to frame propagation of Lakshadweep During the westward propagation LL correction series is necessary in order to the correct diurnal variation as per Low on the thermal structure of intensifies from surface to subsurface reduce the uncertainties in the short-term observation for some stations. the southern Arabian Sea which is inferred from the deepening wind observation data1. Good data is key of SSH and also the upwelling of 24o Overall, the statistical analysis of RMSE, Author Johnson Zachariah to good WRA and to predict accurate isotherms. From the analysis it is seen wind energy production of a site. MAE and BIAS of MERRA, ERAI, NNRP Affiliation Cochin University of that the mechanism of intensification and FNL shows small variations with Science and Technology throughout its westward propagation is The objective of the study is to compare observations. However, ERAI reanalysis Co-authors due to the cyclonic shear generated from the wind speed modelled by MERRA, performed better than other reanalysis Johnson Zachariah(Cochin University of the northward gradient of the core of the ERAI, NNRP reanalysis and FNL analysis data, even if the selection of reanalysis Science and Technology), C .A. Babu equatorial surface jet stream (Wyrkti Jet) data sets with observations across 10 data for WRA still depends on the (Cochin University of Science and existing at the equatorial Indian Ocean stations in India over the recent period location of site. Technology), Hamza Varikoden(Indian during September to December and its of 2010-2016. The observation data Institute of Tropical Meteorology) westward advection from the central is obtained from National Institute of Indian ocean to the western margin. The Wind Energy (NIWE), India. The stations According to the earlier reports correlation computed between SSH and selected in the study are geographically Lakshadweep Low (LL) propagates cyclonic shear shows high value from well dispersed across India containing westwards near to the western margin September to December. mixture of complex, urban and on-shore of the Arabian Sea since its genesis locations. These reanalysis data have near to the southern tip of India. different spatial and temporal resolution Analysis of Sea surface height anomaly of grids. (SSH) and subsurface temperature The gridded reanalysis data therefore structure using the GODAS (Global is interpolated at the station location ocean data assimilation system, NCEP) using inverse distance weighted (IDW)

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 144 Section 5

China and North China, which result in The North Atlantic jet stream is important data set to expose any secular trends. Interannual and Decadal a meridional tripole structure of rainfall for aviation, influencing flight routes, Our primary results are independent of Variations of Moisture Flux anomalies in eastern China, i.e., droughts journey times, turbulence, and possible computer models. by Asian Summer Monsoon (floods) in the middle and lower reaches effects of climate change. This study and Associated Rainfall Anomaly of the Yangtze River and the Yangtze- used a dense set of aircraft observations Huaihe valley but floods (droughts) in relative to the Aircraft Meteorological Intercomparison of monthly Patterns in China South China and North China. Data Relay (AMDAR) system and with Euro-Atlantic weather regimes the addition of a turbulence measure (the obtained from different Author Jilong CHEN On decadal scale, persistent floods in the Global Aircraft Data Set, GADS). Affiliation Institute of Atmospheric middle and lower reaches of the Yangtze reanalysis and of their influence Physics, Chinese River but persistent droughts in South Wind speeds and turbulence were on wind energy resources Academy of Sciences China and North China are mainly linked obtained every 4 sec (~ 1 km spacing) at Author Nicola Cortesi Co-author with weakening of VIMF by ASM and a fixed flight level (FL370, ~ 225 hPa). We Affiliation Barcelona Jilong Chen (Institute of Atmospheric a dipole VIMF anomaly in the western examined the winter (DJF) North Atlantic Supercomputing Center Physics, Chinese Academy of Sciences) North Pacific after the end of 1970s. In jet stream region to study secular trends view of the in-phase relationship between in wind speed and “light” turbulence. Co-authors The NCEP/NCAR reanalysis data summer rainfall anomalies and VIMF The observations were compared with Nicola Cortesi, Nube González-Reviriego, (NCEP-R1) and the ECMWF reanalysis convergence anomalies in China, the reanalyses over a 12 year period, winter Veronica Torralba, Albert Soret, data (ERA-40) for the period of 1958- analysed results also show interannual 2002-2013 (labeled by the January year), Francisco Javier Doblas-Reyes 2002 are used to estimate interannual and decadal variations of VIMF by ASM and a CMIP study of doubled CO . 2 For wind energy companies, it is crucial and decadal variations of vertically can be better described by the ERA-40 We have a sufficiently large dataset (3 to identify the main sources of wind integrated moisture flux (VIMF) by reanalysis than the NCEP-R1 reanalysis. Asian summer monsoon (ASM) and billion total global observations, 500,000 speed variability affecting their wind investigate their association with summer for the North Atlantic per winter month) farms, at all time scales. It is known that rainfall anomalies based on monthly Interannual variations and that we are able to subdivide the results changes in the frequencies of occurrence precipitation at 160 stations in China. secular trends in winter North into five longitude bands at ten degree of the monthly Euro-Atlantic weather Atlantic jet stream wind speeds intervals running from 60°W to 10°W and regimes determine most of the variation The results show that both VIMF by ASM find quite coherent behavior along the of wind speed anomalies over Europe and summer rainfall in China exhibit and turbulence from the GADS North Atlantic jet. As would be expected, (Hannachi et al., 2017). obvious biennial rhythms as revealed by data set our results match the interannual Firstly, the impact of the monthly time coefficient of the leading EOF mode. reanalysis variations of the North Atlantic Author Joel Tenenbaum frequency of the four main monthly When summer VIMF is strong (weak) in jet. the south Asia monsoon region, a dipole Affiliation SUNY Purchase weather regimes on 10-m wind VIMF anomaly in the East Asia – western Co-authors They are also consistent with conclusions speed variability over Europe has North Pacific is propitious to negative J. Tenenbaum (State University of New of Delcambre et al. (2014) for doubled been evaluated. Subsequently, an (positive) VIMF convergence anomalies York (SUNY), Purchase, NY, USA), CO2: that the wind speed for the jet exit intercomparison of the spatial patterns in the middle and lower reaches of P. D. Williams (University of Reading, region shows a strengthening and the and frequencies of the monthly weather the Yangtze River and the Yangtze- Reading, UK) core shows a weakening. The trends in regimes derived from daily sea level Huaihe valley but positive (negative) “light” turbulence are less clear, because pressure data during last 35 years has VIMF convergence anomalies in South the rarity of turbulence and the large interannual variability demands a longer

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 145 Section 5 been performed for three different (TIRS) for 2016 spanning a period of 30 reanalyses: JRA-55, ERA-Interim and years. Dramatic increase in land surface Marine Forecasting Systems MODIS images and ERA-Interim NCEP/NCAR. temperature and area radiation have in Caspian Sea, Persian Gulf reanalised data for estimate a occurred, with their impacts on human Finally, the spatial structure of the four and Oman Sea time series of energy balance health. weather regimes has been related to Author Alireza Vaselali components at humid subtropical the four main monthly teleconnection Rapid urbanization in the study Affiliation Behin Tarhe Appadana climate in South of Brazil patterns in the Euro-Atlantic region (NAO, area contribute significantly to this (BETA Group) EA, EA/WRUS and SCAND) obtained drastic change in the natural surface Author Juliano Schirmbeck from the same reanalysis. Results characteristics, this includes increased Co-authors Affiliation Federal University of Rio confirm the usefulness of the monthly land surface temperature and surface 1. Alireza Vaselali (Head of Design and Grande do Sul State/ classification for the characterization of solar radiation. The analysis of Landsat Technology Department, Beta Group Research Center for the monthly wind speed variability over images of the study area revealed that Consulting Engineers), 2. Aliasghar Remote Sensi most part of Europe. there is a decline in vegetation cover Golshani (MetOcean Expert, Beta Group Co-authors and increase in thermal characteristics, Consulting Engineers), 3. Said Mazaheri Juliano Schirmbeck (Federal University and these changes have forced the (Research Assistant Professor, Iranian Investigating land surface of Rio Grande do Sul/State Research development of urban climate to have a National Institute for Oceanography and Center for Remote Sensing and temperature and estimated significant effect on human health. Atmospheric Science) Meteorology), Denise Cybis Fontana radiation as human health The radiation extracted from Landsat There are several global marine forecast (Federal University of Rio Grande do implications in East London images revealed that there is an increase systems based on large scale regional Sul/Dept. of Forage, Plant and using remote sensing and GIS in radiation and in all the years, the value data covering Iranian seas which are Agrometeorology), Lucimara Wolfarth approach exceeded the global solar radiation freely available on their websites. They Schirmbeck (Federal University of Rio index and exposure to such ultra-violet are also several local marine forecast Grande do Sul/State Research Center for Author Israel Orimoloye radiation can result in heat stroke, skin systems in Iranian waters. This paper Remote Sensing and Meteorology) Affiliation University of Fort Hare, cancer, and heart disease. Consequently, performs an inter-comparison among Alice South Africa Spatial and temporal patterns of the further research is therefore needed different marine forecasting systems energy balance (BE) components Co-authors to understand the human health and in Iranian seas in order to evaluate the provide very important information to Department of Geography and its association with natural surface accuracy and difference between them the agronomic context, especially over a Environmental Science, University of Fort characteristics and epidemiological and give a proper ground for further grain production area like of Rio Grande Hare, Alice South Africa cases. investigation and research in this crucial do Sul at soul of Brazil. The most of issue. For this purpose, the results of two This study illustrates the significance of models for estimate energy balance Land surface temperature and estimated forecasting system in several points in remote sensing and GIS for this purpose. form satellite images are based on the radiation of East London city in Eastern the Persian are compared and the reason Keywords: Land Surface Temperature, combined use of terrain meteorological Cape Province of South Africa were of differences are investigated. produced from remote sensing data Radiation, Human Health, Remote variables and image data, sometimes using GIS techniques from Landsat sensing, Exposure. a specific a single point data are not Thematic Mapper (TM) images for 1986, representative for regional studies. 1996, 2006, and Operational Land Imager (OLI), Thermal Infrared Sensor

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 146 Section 5

Because this, the purpose of the study in the construction of series capable of however, in the recent decades, the LLJ was evaluate the estimative of the energy adequately representing the seasonal core is passing at 150N. A shift of 50 Number of melt days and balance components with combined patterns of BE components. towards north is very lucid. atmospheric conditions in use of MODIS (Moderate Resolution The maximum wind strength at 850 hPa Greenland in 2000-2014 Imaging Spectroradiometer) products is noticed over the central Arabian Sea and ERAInterim reanalysis data. For Northward migration of Low Author Ilona Välisuo with wind strength of more than 18 m s-1. this, the MODIS products (surface Level Jetstream and its Impact Affiliation Finnish Meteorological The location of maximum wind strength temperature, albedo, vegetation index on Indian Summer Monsoon Institute is also shows a shift from 12.50N to and leaf area index), EraInterim data using Reanalysis data set 140N, indicating an overall migration Co-authors (air temperature, global radiation and of LLJ core towards north. The LLJ I. Välisuo (Finnish Meteorological wind velocity) and micrometeorological Author Hamza Varikoden movement towards the north influences Institute), T. Vihma (Finnish tower data (Eddy Covariance) were Varikoden the rainfall pattern over the west coastal Meteorological Institute), R. Pirazzini used for apply the METRIC (Mapping Affiliation Indian Institute of Tropical regions. The trend analysis of rainfall (Finnish Meteorological Institute), M. Evapotranspiration with Internalized Meteorology from India Meteorological Department Schäfer (Finnish Meteorological Institute) Calibration) energy balance model and Co-authors (IMD) gridded data set reveals that a estimate the RN (Net Radiations), LE Surface melt on Greenland ice sheet Hamza Varikoden (Scientist), J. V. drying trend in the southern regions and (latent heat), H (sensible head) and G and extremely warm temperatures in the Revadekar (Scientist) and CA Babu a wetting trend in the northern regions of (ground heat flux). The study area was Arctic since 2007 have been linked to (Professor) western Ghats. humid climate region, the area of Rio negative North Atlantic Oscillation (NAO) Grande do Sul state. The study period Indian summer monsoon is a season The movement of LLJ towards north will in numerous studies. Cases of extreme was along of 3 years (2009 to 2011), with associated with southwesterly winds lead a divergence zone over the south melt on Greenland are also related to periodicity of 8 days. The results showed at lower levels extending from June and convergence zone over the north. anticyclonic circulation centered over that model of BE estimation presented to September and it brings copious This divergent and convergent pattern Greenland, which favours warm-air of distribution patterns similar to those moisture from the nearby oceans to is mainly responsible for the drying and advection to Greenland. of the micrometeorological tower, with support monsoon rainfall in the Indian wetting trends of rainfall over the south We investigate the connections between predominance of the LE component subcontinents. The modulation of low and north regions of western Ghats. interannual variations of the number of in summer and winter and alternation level wind is studied based on the NCEP- melt days on Greenland ice sheet and between these components in the partial NCAR and ERA reanalysis products. atmospheric and surface conditions in coverage periods. The study is carried out using the data from 1948 to 2016 during the southwest 2000-2014. We calculate the number The OSEB model presented greater monsoon period (JJAS period). of melt days using a MODIS based coherence with the tower, both in product on ice surface temperature. standards and in magnitudes, but We examined the changes in a northward As the spatial coverage of the MODIS provided a greater loss of data; Of migration of the Low Level Jetstream product is limited, we complement it with the total of 136 images analyzed the (LLJ) core from the early decades (1948- ERA-Interim surface temperature. To METRIC model presented consistent 1957) to recent decades (2006-2015). In quantify melt, we use also satellite based results for a total of 103 images. This the early decades the LLJ core located at maximum and cumulative melt extent, is an important factor to be considered 100 N while passing the western coast, and a modelled value for the melt water production. The evaluation of different

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 147 Section 5 melt variables reveals that different years level convergence and cyclonic vorticity will be identified as years of extreme melt Observational Features of Bogus and it plays vital role on the formation of On the sensitivity of Antarctic depending on how melt is quantified. Monsoon Onset using the cloud bands. sea ice model biases to Our study includes a comparison Reanalysis Data Set The evolution of the cloud band over atmospheric forcing between the ice surface temperature Author Sreelekha P N the equatorial region, its northward uncertainties of the MODIS product and ERA- propagation, development of cross Affiliation Cochin University of Author Antoine Barthélemy Interim surface temperature. ERA- equatorial flow near the Somalia coast, Science and Technology Interim’s surface temperature is found appearance of equatorial westerly wind Affiliation Université catholique de to be mostly warmer than MODIS Co-authors etc. resemble closely to that of the Louvain IST. However, the difference in the P N Sreelekha (Cochin university of monsoon organized convection. High Co-authors temperatures is smaller when the Science and Technology), C A Babu values of vertical wind shear during the Antoine Barthélemy (Université temperatures are close to the melting (Cochin university of Science and BMO also help the formation of rain catholique de Louvain), Hugues Goosse point. Technology) spells similar to that during monsoon. (Université catholique de Louvain), Due to the evolution of the rising motion, We study the weather conditions in The study investigates the features of Thierry Fichefet (Université catholique de the ascending limb of the local Hadley March-May and June-August separately rain spells associated with the organised Louvain), Olivier Lecomte (Université circulation gets shifted towards the to understand which kind of atmospheric convection that occur over southwest catholique de Louvain) region of the BMO. conditions occurred in the early stage peninsular India during pre-monsoon Although atmospheric reanalyses are of the melt season, as well as during Further, the ascending limb shifts to the season. Since the rain spells are similar an extremely valuable tool to study the the strongest melt. Our interest is north along with the BMO. The velocity to that during monsoon season, we call climate of polar regions, they suffer from especially in the surface temperature, potential values derived from the winds the phenomenon as Bogus Monsoon large uncertainties in these data-poor near surface wind, total cloud water at 850 hPa and 200 hPa levels confirm Onset (BMO). The phenomenon is areas. In this work, we examine how content and atmospheric pressure. The the rising motion on the basis of low level different from the pre-monsoon thunder Antarctic sea ice biases in an ocean-sea meteorological variables are retrieved convergence and upper level divergence. shower with respect to the time of ice model are related to these forcing from ERA-Interim and NCEP-CFSR Positive phase of intraseasonal oscillation occurrence, duration, intensity and uncertainties. reanalyses. spatial extension. is noticed on the OLR pattern associated with the formation of the bogus monsoon Three experiments are conducted in The thunder shower is caused by the onset over the southwest peninsular India which the NEMO-LIM model is forced local convection and occurs as heavy during the pre-monsoon season. by different atmospheric forcing sets. shower over a small area in the afternoon The minimum ice extent, the ice drift for less than an hour. The BMO rain is and the ice thickness are sensitive to the light, occurs over a wide area at any reanalysis chosen to drive the model, time of day and persists for more than a while the wintertime ice extent and inner week. During a pre-monsoon season, 2 pack concentrations are barely affected. or 3 rain spells associated with the BMO are formed. The analysis was carried The analysis of sea ice concentration out utilising wind and humidity data budgets allows identifying the processes from JRA reanalysis products, NOAA leading to differences between the OLR and IMD rainfall. We found that the experiments, and also indicates that ascending motion is caused by the low

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 148 Section 5 large and similar errors compared to Each product contains parameter series for a single point, an area, a South America precipitation variability observations are present in all three numbers varying from 2 to 125. Due political boundary, such as countries, or in the PDO scale, from 1970 to 2003, is cases. to the large number of products, data a water shed. studied through anomalous composites files, and data volumes, it is a challenge and EOF analysis. Monthly GPCC data, Our assessment of the influence of Application research studies concerning for users to find and download the only NCEP-NCAR reanalysis I, ERA40 and forcing inaccuracies on the simulated renewable energy, extreme weather, and parameters and spatial region of interest. JRA55 reanalysis were considered. Antarctic sea ice allows disentangling the air quality, etc. require long-term data at The data support team at GES DISC, Results are shown for distinct PDO model biases that can be reduced thanks high temporal resolutions. With native working closely with the MERRA-2 phases from 1970 to 2003, 1970-1976 to better atmospheric forcings from those file structure of the hourly data, it is a science team, has created value added (negative PDO phase), 1977-1996 that would require improvements of the challenge for users to download what data tools and provided high quality (positive PDO phase) and 1997-2003 physics of the ice or ocean model. they need. For example, extracting one services to the broad user community. (negative PDO phase). Seasonality and parameter at a single point for 30 years MERRA-2 subsetter is a powerful linear trend were removed from the may take over 15 hours. Moreover, users data tool for downloading selected original data. The 3rd EOF mode applied Online Visualization and Value wish to have such a long time series in a parameters, region, and time. on GPCC data shows a dipole pattern Added Services of MERRA-2 single file. over the central-eastern South America Data at GES DISC One function is, with a number of The GES DISC is exploring methods with reversal signal for distinct PDO interpolation methods, to regrid the Author Suhung Shen for the improvement of accessing big phases, as mentioned in the literature. spatial resolution to models, such as model data. One approach attempts to During the negative PDO phases, there Affiliation George Mason University ERA, cfsr, GEOS, GLDAS, etc., and to optimize file structure. Initial performance is less precipitation over a north-eastern & GES DISC NASA save the data in a different format. In tests of year-file of hourly data have area and more precipitation over a south- Co-authors addition, the interoperable services, such shown dramatic improvement of the eastern area. During the positive PDO Suhung Shen (George Mason University as OPeNDAP and GDS are provided accessibility. phase, the reversal spatial pattern is and NASA), Dana M. Ostrenga (ADNET for remote accessing data via using observed. and NASA), Bruce E. Vollmer (NASA), applications such as Matlab, GrADS, R, Mahabaleshwa S. Hegde (ADNET and IDV, etc. Selected MERRA-2 parameters Precipitation anomalies in This result is in general observed in NASA), Jennifer C. Wei (ADNET and have been integrated into Giovanni, an distinct PDO phases over South the anomalous fields obtained for the NASA), Michael G. Bosilovich (NASA) online visualization and analysis system America based on NCEP-NCAR NCEP-NCAR reanalysis I, JRA-55 e developed in-house at GES DISC. ERA40 datasets. However, NCEP-NCAR NASA climate reanalysis dataset from Reanalysis I, JRA55 and ERA40 reanalysis I presents more intense Giovanni has more than twenty MERRA-2, distributed at Goddard Earth anomalies in relation to JRA55 and ERA40 visualization functions that enables Author Carlos Batista Silva Sciences Data and Information Services datasets. ERA40 precipitation anomalies easy and quick exploration of data by Affiliation Department of Center (GES DISC), contains numerous present the weakest values over oceanic performing basic statistical analysis Geography University of data for atmosphere, land, and ocean, areas. The anomalous precipitation mean and comparisons between variables. São Paulo, Brazil that are grouped into 94 products of fields over the adjacent oceanic areas to For example, it generates maps with archived volume over 333 TB. The data Co-authors the north of the South America present user defined time range and is able to files are saved as day-file and month- C.B. SILVA (Department of opposite signs between NCEP-NCAR adjust the color scales for best showing file for hourly and monthly time interval GeographyUniversity of São Paulo, reanalysis I and JRA55 data, for the 1st interested signals. It generates time respectively. Brazil), M.E.S. SILVA ((Department of and 2nd PDO phases. GeographyUniversity of São Paulo, Brazil)

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 149 Section 5

Opposite signs between NCEP-NCAR downscaling project of CORDEX- producers of reanalysis datasets. The WRIT Timeseries, allows users to plot and JRA55 precipitation can also be SEACLID) in 25 km of scale, in three first is the website “Reanalyses.org”. similar datasets but instead compare seen over the central South America. In future period (2021-2030, 2031-2040 and Using a collaborative Wiki framework, gridpoint or area-averaged time-series. general, the ERA40 precipitation anomaly 2041-2050). the goal of reanalyses.org is to facilitate Users can plot and/or compare time- patterns are in more agreement with that comparison between reanalysis and series, specifying the region or season. Annual climate factors such as rainfall, based on NCEP-NCAR reanalysis I. observational datasets. Land/ocean masking functionality is temperature and Oldeman climate available. A full set of statistics is output. type are simulated, with elevation as To accomplish this, reanalyses. The 3rd tool, WRIT Distributions, can topography supporting element. Climatic org is divided into reanalysis types: Projection of rice plants climatic be used to examine the distributions of suitability weighting on paddy rice Atmosphere and Ocean (with Land to suitability based on daily data from several reanalysis and plants based on FAO is used as analysis come). Each type includes webpages representative concentration observed datasets. technique without considering soil that describe the datasets, provide pathways (RCP) 4.5 and 8.5 in condition. references, help users obtain the data, Users can compare distributions to East Java, Indonesia directs users to plotting and analysis each other and to a set of provided The results reveal climatic factors are not tools for the data, and provides a place distributions. The 4th tool, WRIT Author Femmy Marsitha an obstacle to paddy rice plantation in for researchers to describe their research Trajectory, allows users to plot Agency of Meteorology East Java until 2050. The whole research Affiliation using the reanalyses. atmospheric trajectories from several Climatology and areas show an adequate suitable climate reanalysis datasets using 4x-times daily Geophysics Region IV (S2) for paddy rice over future 1 up to Pages can be edited by validated users. pressure level data to calculate the path future 2 using both scenarios, except Anyone can post a comment on most Co-authors of tracer particles. Femmy Marsitha the climate at eastern of East Java will pages with experts available to answer be marginal suitable that need to be questions. The pages are searchable and As one of paddy rice central in the world, anticipated. indexed. There are even “private” areas Replicating Annual North Indonesia need to improve continuously for groups such as the WCRP Task Team Atlantic Hurricane Activity food resilience through adaptation and for the Intercomparison of ReAnalyses 1878-2012 from Environmental mitigation of global changing climate. Reanalyses.org: Advancing user (TIRA) to collaborate. To the Tools area Climate change could be claimed as and producer needs for of Reanalyses.org, CIRES and PS have Variables causes paddy rice plants are not suitable reanalysis with services and contributed the “WRIT” or Web-based Author Philip Klotzbach Reanalysis Intercomparison tools at anymore to develop in particular area. To tools Affiliation Colorado State University provide scientific support against effect https://www.esrl.noaa.gov/psd/data/writ/. Catherine Smith of climate change, climatic suitability Author Co-authors There are currently four tools available. Philip Klotzbach (Department of analysis up to the future need to be done Affiliation NOAA/ESRL PSD In the Writ Maps Tool, one can plot Atmospheric Science, Colorado State in order to plan rice plantation. Co-authors maps and cross-sections from monthly- University)Mark Saunders (Mullard Space CA Smith (NOAA/ESRL PSD and CU This research aimed to project climatic mean fields of reanalysis datasets. One Science Laboratory, University College- CIRES), GP Compo (NOAA/ESRL PSD suitability in the biggest paddy rice can also plot the difference of any two London)Adam Lea (Mullard Space and CU CIRES) central production province in Indonesia, datasets. Users can examine means, Science Center, University College- East Java using RCP4.5 scenario as ideal The University of Colorado/CIRES and anomalies, or climatologies using London) condition representation and RCP8.5 NOAA/ESRL Physical Sciences Division different seasons and sets of years. scenario as the worst probability from host two types of support for users and Some other observational datasets are CSIRO model (the result of dynamic provided for comparison. The 2nd tool,

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 150 Section 5

Statistical models can replicate annual We identify a dropout in hurricane In addition, spatial decision-making Indonesia. SACA&D plays an important North Atlantic hurricane activity from replication centered on the 1940s and problems are multicriteria nature. For this role in climate information and monitoring large-scale environmental field data for show that this is likely due to a decrease purpose, the multicriteria hierarchical in the region especially for the ASEAN August and September, the months of in data quality which affects all data sets analysis (AHP) method was applied and pacific region. It’s built of the peak hurricane activity. We assess how but Atlantic sea surface temperatures in to ERA-Interim reanalysis data from cooperation between BMKG Indonesia well the six environmental fields used particular. Finally we offer insights on the ECMWF coupled with cyclonic data and KNMI Holland in supported by 10 most often in contemporary statistical implications of our findings for seasonal and socio-economic data, in order to ASEAN member countries, and 6 others modeling of seasonal hurricane activity hurricane prediction. break down the complex problem into countries in the Pacific region included of replicate North Atlantic hurricane a structure Hierarchical analysis for Australia. All 16 countries has contributes numbers and Accumulated Cyclone risk analysis and vulnerability to major a climate daily observation data with 10 Energy (ACE) over the 135-year period Risk and vulnerability analysis in hazards in Madagascar. parameters and synoptic data which from 1878 to 2012. Madagascar using AHP method is GTS exchanges data every 3 hourly and other source data from GHCN and We find that these fields replicate Author RAKOTOARISON Tsiory SACA&D gridding data as a tool ECMWF data model as a comparison and historical hurricane activity surprisingly EMIT University of Affiliation for climate monitoring and to complete the data. Quality control data well, showing that contemporary Fianarantsoa information services for the in SACA&D is using homogeinity test from statistical models and their seasonal Co-authors Wijngard to clasify the data is usefull, physical links have long-term robustness. Asean and Pacific Region RAKOTOARISON Tsiorinantenaina René doubfull and suspect. The other methods We find that August-September zonal (Ecole de Management et d’Innovation Author Sunaryo Naryo are called blending and non blending to trade wind speed over the Caribbean Technologique, Université de Affiliation BMKG Indonesia extend the period of climate data. Sea and the tropical North Atlantic is the Fianarantsoa, Madagascar), environmental field which individually Co-authors Meta information for the daily series HAJALALAINA Aimé Richard (Ecole de SUNARYO replicates long-term hurricane activity Management et d’Innovation is provided methode both for the the best, and that trade wind speed Technologique, Université de SACA&D is a Website visualisation of blanded and non blended series. The combined with the difference in sea Fianarantsoa, Madagascar) the climate dataset for the ASEAN and blended series have been tested for surface temperature between the tropical Pacific region. homogeneity, which is relevant to assess Atlantic and the tropical mean is the best The major hazards, namely cyclone, the quality of each series for climate multi-predictor model. flood and drought, occur frequently SACA&D is a part of ICA&D (International change information. To get the climate and periodically in Madagascar. Climate Assessment and Dataset) monitoring and information services in Comparing the performance of the best These extreme phenomena cause network which is consist of WACA&D the ASEAN and Pacific region, there are single-predictor and best multi-predictor direct mortality, flooding, damage to (West Africa), LACA&D (Latin America), available in 44 indices included trends, models shows that they exhibit little infrastructure such as roads, schools, SACA&D (Asean and Pacific) and ECA&D changing probabilities of high impact difference in hindcast skill for predicting health centers and population centers, as (Eropean) to get access of SACA&D extremes like as droughts, floods, health long-term ACE but that the best multi- well as crop destruction and landslides. website is http://sacad.database. risk, inparticularly of food security, predictor model offers improved skill for Disasters hamper development programs bmkg.go.id. Agency of Meteorology, energy, transportation and others. Indice predicting long-term hurricane numbers. and result in loss of people’s property Climatology and Geophysics of Indonesia extremes are available in form of time We examine whether replicated real-time that leads to a decline in the economic Jakarta (BMKG) has managing this series plot, trend maps, anomaly map prediction skill 1983-2012 increases as level. Risk and vulnerability analysis is Website and it has launched in the event index, climatology maps for this region. the model training period lengthens and a necessary part of decision-making of the Second International Workshop find evidence that this happens slowly. on risk and disaster management. of SACA&D on April 2012 in Bogor

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 151 Section 5

Data Gridding of the SACA&D developed some atmospheric variables from the between KNMI Holland and BMKG to South African Summer Monsoon European Center of Medium-range Southern Annular Mode Trend increase the Climate monitoring and active and break spells cloud Weather Forecast (ECMWF) datasets. based on Reanalysis information services namely SA-OBS properties: Five years analysis Results obtained show that cloud base Version1.0 and It had used effectively Author Noele Franchi Leonardo from CloudSat-CALIPSO heights (CBH) and cloud top heights in 2016 until now. SA-OBS made with Affiliation Federal University of (CTH) show both bimodal distributions regular grid 0.25o and 0.50o With observations. Vicosa during both phases of the monsoon coverage area all ASEAN country Author Efon Eric season. Moreover, more high level clouds Co-authors between 25o North to 25o South and Affiliation University of Douala were observed during the active spells N. Leonardo (Federal University of from 80o East to 180o East and available than during the break spells. The results Vicosa), F. Justino (Federal University in NetCDF format. SA-OBS consist of 4 Co-authors were attributed to background wind of Vicosa), A. Silva (Federal University parameters of daily value for TX, TG, TN Eric Efon (Laboratory of Fundamental regime, which remains easterly during of Vicosa), V.Schumacher (Federal and RR with period data from 01 January Physics, Department of Physics, Faculty both spells, but with winds occurring University of Vicosa), A. Comin 1980 to 31 Dec 2014. Station density of Science, University of Douala, P.O. during the active spells stronger that that (Federal University of Vicosa) of this RR is 5979 series observations Box 24157 Douala, Cameroon.), Andre prevailing during the break spells. throughout of ASEAN and a part of Lenouo(Laboratory of Fundamental Several studies indicate a positive trend Pacific. There are 3 step methods of Physics, Department of Physics, Faculty Some mid level westerly winds were of the positive phase of Southern Annular SA-OBS, one of the method is an of Science, University of Douala, P.O. also observed over the monsoon core Mode (SAM) in recent decades. In this interpolation of monthly mean/total using Box 24157 Douala, Cameroon, ICTP – zone during the active spells. In addition, study three datasets have been used: thin plate splin to define the spatial trend, Strada Costiera, 11, I – 34151 Trieste at lower level, cyclonic vorticity prevail ERA-Interim, JRA-55C, 20th Century daily anomalies using global kriging with Italy), David Monkam(Laboratory of during the active spells while during Reanalysis for the period 1980–2012. a single variogram for all days. Fundamental Physics, Department of the break spells, the vorticity was In order to evaluate the robustness of Physics, Faculty of Science, University of anticyclonic. Deep clouds, Mid- and the potential trend, the non-parametric Climate information and monitoring Douala, P.O. Box 24157 Douala, high-level clouds have higher (ice water Mann-Kendall (MK) and Sen’s methods product of SA-OBS are daily maps for 4 Cameroon) and Desmond content) IWC, (ice number concentration) have been applied. The SAM pattern elements TN, TX, TG and RR closely of Manatsa(Faculty of Science, Bindura INC and Rice (ice effective radius) between reanalysis are very similar the ASEAN and Pacific region. Benefits University of Science Education, P. Bag during the break periods than the active in magnitude and variability and all of the SACA&D gridding data is the 1020, Bindura, Zimbabwe, ICTP – Strada periods while Low-, mid-, high-level and reanalysis has a high correlation with monitoring extreme events in the region Costiera, 11, I – 34151 Trieste Italy) deep convective clouds have relatively CPC/NOAA SAM index. when La Nina and El Niño year and its higher values of (liquid water content) impact like as drough, flood, forest fire. In Daily rainfall data from the Tropical The MK test was statistically significant LWC, (liquid number concentration) LNC the National level, BMKG has developed rainfall measuring mission (TRMM) was for all reanalysis data and also for the and Rliq (liquid effective radius) during the climate data online services used to identify the active and break CPC/NOAA dataset, indicating that all the active spells than during the break included gridding data and Indonesia spells of the South African summer reanalysis reject the null hypothesis. It spells. Liquid phase clouds have more has implemented the data policy by monsoon, and properties of clouds is observed that positive trend of SAM radiative forcing, and below 8km, more WMO resolutions 60 and followed by occurring these periods were analyzed is persisting and increasing. The slope atmospheric heating is observed while Goverment regulation that the cimate using CloudSat and CALIPSO satellites of the trend line for all reanalysis is not above 10km, cooling is observed during data is free charge for public. merged data products. In order to better very large in magnitude, but it is positive. explain the results obtained, we used the active periods.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 152 Section 5

Regression analysis were performed to Instituto de Investigaciones Marinas y The minima show stationarity (no trend). understand the relationship between Costeras (IIMYC-UNMDP-CONICET)), The intra-decadal quasi-cycles are Spatial variability of Indian SAM and ocean-atmosphere heat fluxes. D.C. Araneo (Facultad de Ciencias dominant in both seasonal streamflow summer monsoon rainfall and Exactas y Naturales (FCEN), Universidad maxima and minima. Teleconnections The spatial pattern shows a wave-like responsible factors Nacional de Cuyo (UNCuyo), CONICET). related to the streamflow were analyzed feature for all reanalysis, that can be using ERA-Interim, NCEP/NCAR I, 20C, Author Suthinkumar P S explained by the anomalous meridional Patagonia is under influence of the and ERA-20C reanalysis datasets and Affiliation Cochin University of and zonal strengthening associated westerlies that drive the amount and other oceanic and atmospheric global science and technology, with positive phase of SAM. Analysis of distribution of precipitation in the datasets. Detrended streamflow maxima cochin, India different reanalysis demonstrated that Southern Hemisphere (SH) middle are linked to a quasi-stationary Rossby Co-authors differences in their grid resolution and latitudes. Two sub regions with highly wave (QSW). Suthinkumar P S (Department of model dynamics project very similar distinct precipitation features are: wet Atmospheric Sciences Cochin University response to the SAM insofar radiative Western Patagonia, from the Pacific Tropospheric circulation anomalies, of Science and Technology, Cochin fluxes are concerned. coast to the Andean highs; and dry symmetric about the equator, are 682 016, India), C A babu (Department of Eastern Patagonia, leeward the Andes in possibly associated with tropical Atmospheric SciencesCochin University the Argentine steppe plateau towards the convection, induced by anomalous SST Southern hemisphere low- of Science and Technology, Atlantic. in the equatorial western Pacific. The frequency troposheric QSW affects the position and intensity Cochin 682 016, India) circulation components and The cold season (Apr-Sep) is the rainy of the subtropical and polar jets, Indian summer monsoon is associated season over the mountains in central altering winter precipitating transient their contribution to river runoffs with convective cloud bands. These Patagonia (40°S-50°S), leading to snow perturbations. Detrended streamflow changes in Central Eastern surges are originated over the equatorial accumulation over river catchment areas. minima are linked to a high latitude Patagonia Indian Ocean and move northward up to The winter snow feeds river runoffs to annular mode-like variability, modulated the foot hill of Himalaya. The passage of Author Eduardo Agosta the east in EP. The Tecka-Gualjaina (TG) by a mid-latitude wave-3 structures the surges produce monsoon rain over River is one of those which drain their over the Pacific and Atlantic. Trend Affiliation UCA/CONICET/FCAGLP the region and the situation is treated streamflow into the South Atlantic, from analysis and inhomogeneity tests on Co-authors as active monsoon. No rain occurs the Andes to the Atlantic. We explored the SH tropospheric circulation fields and E.A. Agosta (Equipo Interdisciplinario in the region when the surge is in the influence of tropospheric circulation and SST anomalies, show significant slow para el Estudio de Procesos equator or near the Himalaya and this sea surface temperature (SST) anomalies components consistent with the trend Atmosféricos en el Cambio Global situation is treated as break or weak on the interannual-to-decadal streamflow and changes in the TG streamflow. (PEPACG) Facultad de Ingeniería y monsoon condition. An investigation is variations of the TG River for the season Trends in tropospheric fields during the Ciencias Agrarias, Pontificia Universidad carried out on the rainfall pattern over of maximum streamflow (Jun-Nov) and river peak season are present even if Católica Argentina “Santa María de los different regions of Indian subcontinent the season of minimum streamflow (Dec- inhomogeneities are removed. Buenos Aires” (UCA), ARGENTINA. May). The maxima show negative trend associated with the evolution and Facultad de Ciencias Astronómicas y along records. There is a change in the propagation of the monsoon surges Geofísicas (FCAG), Universidad Nacional streamflow anomalies by the early 1980s, utilizing daily values of NOAA OLR, gpcp de La Plata (UNLP). Consejo Nacional de evolving from a positive predominance rainfall and Investigaciones Científicas y Técnicas before to a negative one after. (CONICET)), R.A. Maenza (Grupo de Geología de Costas y Paleoecología,

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 153 Section 5

NCEP reanalysis wind and humidity data. Descriptive statistics has been The horizontal extension and intensity Spatio-Temporal Variability and Statistical analysis of long term performed to obtain in annual, monthly of the surges, features on the cross Trend of Water Vapour Density precipitation records in coastal and seasonal descriptive information equatorial flow and the low level jet across Nigeria using Reanalysis region of Bangladesh of precipitation records. Least squares stream, dynamical characteristics such and NIMET Data linear regression (LSR), Mann Kendall as vorticity pattern, divergence pattern, Author Mr. Nasir Uddin (MK), Modified Mann Kendall (MMK) vertical velocity and the vertical time Author Israel Emmanuel Affiliation Bangladesh Centre for test, Seasonal Mann-Kendall (SMK) test, section of specific humidity associated Affiliation Federal University of Advanced Studies spearman rank correlation, Theil and with the surges are studied. Generally, Technology, Akure (BCAS) Sen’s slope estimation test, trend free four to five prominent monsoon surges pre whitening test, Pettitt Mann Whitney Co-authors Co-authors are formed during the season. The test, have been applied to detect the I. Emmanuel (Department of Physics, Md. Nasir Uddin (Senior Research surge possesses cyclonic vorticity in the monotonic trend and magnitude of trend Federal University of Technology, Akure), Officer) lower troposphere and cyclonic vorticity of precipitation records. B. adeyemi (Department of Physics, pattern moves northward along with the Analyzing hydro meteorological series Federal University of Technology, Akure), surge. such as precipitation provides useful E.O. Ogolo (Department of Physics, insights for climatic and hydrologic Statistical Downscaling of 2D Low level convergence and upper level Federal University of Technology, Akure), change in coastal region of Bangladesh. Reanalysis Fields with the divergence are found in the region of A.T. Adediji (Department of Physics, The aim of the study is to perform the Analog Ensemble the surge and along its northward track. Federal University of Technology, Akure) spatial and temporal trend analysis The vorticity and divergence pattern Author Jan Keller of annual, monthly and seasonal helps to form ascending motion over the Using 30 years of European Center for precipitation in coastal Bangladesh. The Affiliation Hans-Ertel-Centre for surge. Analysis was carried out during Medium-Range Weather Forecasts long scale daily precipitation records Weather Research the passage of the surge along longitude (ECMWF) Re-Analysis (ERA-interim) and (1980-2016) of 19 weather stations in Co-authors segments from 5S to 27.5N along 72.5E, Nigeria Meteorological Agency (NIMET) coastal region of Bangladesh have J. D. Keller (Hans-Ertel-Centre for 77.5E and 90E for understanding the data for period of 1985 to 2015, water been collected from Bangladesh Weather Research, Deutscher variability along the Arabian Sea coast, vapour density were estimated across Meteorological Department (BMD) and Wetterdienst, Germany), L. Delle interior and the Bay of Bengal coast. Nigeria. data outlier checked then statistically Monache (National Center for The rainfall features and associated Both spatial and temporal variation were investigated for trend detection. Atmospheric Research, Boulder, USA), mechanisms in terms of humidity and observed across the country. The result S. Alessandrini (National Center for The changing pattern of precipitation circulation in different regions are shows that water vapour density display Atmospheric Research, Boulder, USA) has examined by applying statistical brought out. The Bay of Bengal segment seasonal trend which varies across the parametric and nonparametric gets good rainfall as the surge is intense location. High values of water vapour Reanalyses provide a valuable source procedures. The homogeneity of daily due to the moisture availability and were observed in the southern part of the of information on meteorological observation data has been checked rainfall decreases drastically beyond 20N country. Little discrepancy exist between parameters as retrospective time through Pettitt-Mann-Wheitney test, of the Arabian Sea segment due to the Era-interim and NIMET results in some series. In order to exploit these data, a Standard Normal Homogeneity (SND) moisture cut off in the desert region. locations. However, the general result statistical downscaling approach can shows little agreement between Era test and Von-Neumann test as well be applied. Such an approach acts as interim and NIMET result. as missing data of daily precipitation a correction of systematic errors in the measurement has been estimated using reanalysis with respect to the parameter double mass curve method accordingly.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 154 Section 5

(predictand) in consideration. Reanalysis We tested the accuracy of these data intercomparison has shown the value Supporting the Ground sources before using them in the Surface Solar Radiation at Keti of using very high model resolution observations with ECMWF hydrological model where 5 weather Bandar, Pakistan: A Comparison combined with the assimilation of radar precipitation data to improve the gauging stations were available with a of Observations and NCEP- data with respect to the representation hydrological simulations using full record of daily precipitation amounts NCAR Reanalysis of precipitation in the regional reanalysis from 1979-1996. In addition, daily COSMO-REA2 at 2km horizontal SWAT: the case of Rize basin, average flow data for 15 flow gauging Author Zia ul Rehman Tahir resolution (Wahl et al. 2017). Turkey stations were used from the State Water Affiliation University of Engineering Works (DSI). The daily grid satellite based However, due to the availability of Author Sead Ahmed Swalih and Technology Lahore, precipitation estimates were compared to radar data, COSMO-REA2 only covers Affiliation Istanbul Technical Pakistan the point observed ground precipitation the period from 2007-2013. In our University Co-authors data graphically beforehand. downscaling approach, we use the Co-authors Muhammad Asim (University of analog ensemble technique to generate Sead Ahmed Swalih (Istanbul Technical Then the SWAT model was forced Engineering and Technology Lahore, synthetic time series of 2D precipitation University, Civil Engineering Department, with the precipitation data of MGM Pakistan),Nasir Hayat (University of fields for earlier time periods. Here, we Istanbul, Turkey) Ercan Kahya (Istanbul and ECMWF. The results showed Engineering and Technology Lahore, use the 20-year (1995-2014) data set Technical University, Civil Engineering that ECMWF reanalysis data provide Pakistan) COSMO-REA6 at 6km resolution as Department, Istanbul, Turkey) an estimate of good quality for predictor. precipitation of the basin. Similarly, The surface solar radiation data was Water Resources management the areal comparison indicated a measured by Alternative Energy The probabilistic estimates for the and river flow forecasting in many better performance for ECMWF data Development Board of Pakistan (AEDB) precipitation are created by finding countries is highly hampered by the in capturing the amount and pattern of along with United Nations Development analogs in the existing COSMO-REA2 lack of a sufficiently dense network of precipitation. As expected, the SWAT Programme (UNDP) under the Global data set for each time step in the precipitation. run with the ECMWF data gave a good Environmental Facility (GEF) Wind Energy reconstruction period (1995-2006). The approximation of the flow of the basin. Program at AEDB- UNDP Keti Bandar analogs are determined as the N best In this study, we tested the utility of Mast near Karachi. The solar radiation matches in terms of a metric calculated two Reanalysis data to augment the However, underestimation for the peak data was measured from May 2009 using COSMO-REA6. These analog surface precipitation measurements, flows was observed to some degree. As to October 2010 for the duration of 18 ensembles are then validated against providing improved spatial estimation a conclusion, augmenting precipitation months. The mean daily solar radiation independent observations over central of precipitation and their accuracy was data for poorly gauged watersheds with on this site for the measured duration Europe. tested using a calibrated hydrological good quality satellite based data could is 200 W/m2 and the annual mean daily model (SWAT). The two data sources significantly improve model simulation is 193 W/m2 from November 2009 to used were observed precipitation from outputs. October 2010. Meteorological General Directorate (MGM) and reanalysis precipitation The surface measured radiation data from the European Centre for Medium- is compared with the NCEP-NCAR Range Weather Forecasts (ECMWF-ERA reanalysis 1 data set having a spatial Interim/Land). resolution of 2.5o and temporal resolution of 6 hours. The NCEP-NCAR reanalysis is a joint product of the National Centers

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 155 Section 5 for Environmental Predictions (NCEP) fractal dimension indicates the property The CMF will form an integral part of and the National Centre for Atmospheric of self-similarity, and in the case of The C3S Climate Monitoring the CDS toolbox and will serve a wide Research (NCAR). this study, wherein it is applied to the Facility range of users including the sectorial temporal behaviour of rainfall at a fine information sector and science users. It was observed that the reanalysis data (10-minute) resolution from a total of 44 Author Iryna Rozum This presentation will give an overview overestimates the solar radiation and observatories, it provides insights into its Affiliation ECMWF and demonstration of this online shows a mean bias of 88 W/m2 and more or less convective nature. monitoring tool. RMSE of 35 W/m2. A bias-correction Co-authors method is employed to estimate daily The methodology of Jenkinson & Collison Iryna Rozum (ECMWF), Hans Hersbach solar radiation on the site which shows a which automatically classifies synoptic (ECMWF) The characterization of the similar trend with the surface measured situations at the surface, as well as On behalf of the European Commission, marine renewable energy data. The monthly mean daily measured an adaptation of this methodology at ECMWF operates the Copernicus resource (currents energy), on a and NCEP-NCAR solar radiation shows a 500 hPa, were applied in order to gain Climate Change Service (C3S). C3S very good correlation with the regression insights into the synoptic implications of Moroccan coastal zone using combines climate observations with the SWAN model coefficient of 0.95. The NCEP-NCAR extreme values of the fractal dimension. latest science to develop comprehensive, reanalysis data set can be used to The highest fractal dimension values in quality-assured information about the Author Hazim Salma access the solar potential of Pakistan the study area were observed in places past, present and future state of the Mohamed V University/ using bias-correction method. with precipitation that is more random Affiliation Earth’s climate. As part of this service a IRESEN over time with generally high totals. web-based tool is developed that allows Co-authors users to interactively browse, visualise, Synoptic implications at sea Four different regions in which the HAZIM SALMA (1,2), BENAZZOUZ analyse and compare time series for level pressure and 500 hPa of the atmospheric mechanisms giving rise AISSA(3), GHUENNIOUI ABDELLATIF (2) essential climate variables (ECVs) from to precipitation at the surface differ , EL OUATOUATI AHMED (1), TAHA temporal fractality of various sources as they become available from the corresponding above-ground JANAN MOURAD (1) , NAIMI ZAKARIA precipitation according to the mechanisms have been identified in in the C3S Climate Data Store (CDS). ERA-Interim reanalysis products (2), BADR IKKEN (2)(1): MOHAMED V the study area based on the fractal This includes ECVs directly obtained UNIVERISITY(2): Institut de Recherche en Author Oliver Meseguer-Ruiz dimension. In the north of the Iberian from satellite data (such as from Energie Solaire et Energies Nouvelles Peninsula, high fractal dimension Affiliation Universidad de Tarapacá ESA’s Climate Change Initiative, and (IRESEN)(3):Institut supérieur d’études values are linked to a lower frequency operational products from C3S providers) maritimes ISEM Co-authors of anticyclonic situations, whereas the and reanalysis (such as ERA-Interim O Meseguer-Ruiz (Departamento de opposite occurs in the central region. and ERA5). An associated event data Due to its geographical position, Ciencias Históricas y Geográficas, Morocco has a great renewable energy In the Mediterranean, higher fractal base displays relevant metadata to Universidad de Tarapacá), P Sarricolea resources potential, especially the Marine dimension values are associated with a assist users to correctly interpret and (Departamento de Geografía, Renewable Energy (MRE/EMR). It has higher frequency of the anticyclonic type understand results (including natural Universidad de Chile) 2 seas: Mediterranean and Atlantic and a lower frequency of the advective events such as volcanic eruptions and seas, this last one is characterized by Precipitation on the Spanish mainland type from the east. In the south, lower data events such as changes in the its predictability and potential that is not and in the Balearic archipelago exhibits fractal dimension values indicate higher global observing system). exploited yet. The aim of this work is the a high degree of spatial and temporal frequency with respect to the anticyclonic characterization of the marine renewable variability, regardless of the temporal type from the east and lower frequency energy resource, more precisely the resolution of the data considered. The with respect to the cyclonic type.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 156 Section 5 marine currents, on a Moroccan coastal The content varies depending on the therefore the wealth amount of data that (GLOSWAC). We believe that granted the zone; the Terfaya zone, with a spatial ECV, but typically includes global and is routinely measured and modelled. The rich amount of information contained in resolution of 200m. European maps of anomalies for the challenge associated to the use of the the wave spectrum, this is the future for month and the last year and global spectrum is the increased amount of the characterization of waves. In this work we are interested in the and European time series for monthly information, specially if long term series numerical modeling of marine currents, means and 12 month running means. of spectra are considered. which allows us to describe their The post for each month includes a The impact of resolution on the direction and speed on the studied To work with spectral data while keeping short discussion about the salient points representation of Greenland tip area. Our contribution to this work was the amount of data manageable, we use relevant to that month and ECV. jets, barrier winds, katabatic made using the SWAN digital model. spectral partitioning, a concept physically The characteristics obtained will be The list of ECVs considered, to date, consistent with that of independent flow and channel flow presented in the form of maps or tables is surface air temperature, sea-ice, wave systems (see Portilla et al., 2009). Author Kent Moore of values. precipitation, surface humidity and soil To obtain wave spectral statistics we Affiliation University of Toronto moisture. This presentation will show identify the occurrence probability some of the recent highlights from this distribution of spectral partitions (PDS) Co-authors The contribution of reanalysis climate monitoring, including the record as a skillful indicator (see Portilla et al., G.W.K. Moore (University of Toronto), to climate monitoring high global surface air temperatures 2015). The main advantage of the PDS is I. Renfrew (University of East Anglia), K. Vage (University of Bergen), R. Pickart Author Berrisford Paul experienced during 2015 and 2016 and that spectral long-term features can be illustrated by ERA-Interim. depicted in a very intuitive and distinctive (Woods Hole Oceanographic Institution) Affiliation ECMWF way, such that it becomes a sort of Greenland is characterized by a number Co-authors footprint of the wave conditions at every of low-level high windspeed weather P Berrisford (ECMWF, NCAS-Climate), The global signature of ocean specific site. D Dee (ECMWF), H Hersbach (ECMWF), wave spectra systems that are the result of topographic J Munoz-Sabater (ECMWF), E Remete Here we present a world atlas of wave flow distortion. These systems include tip Author Jesus Portilla (ECMWF), I Rozum (ECMWF), A Simmons spectral statistics. This atlas is based jets, barrier winds and katabatic flow that (ECMWF), J-N Thepaut (ECMWF) Affiliation Escuela Politecnica on the ERA-Interim database from the occur along its southeast coast as well Nacional European Centre of Medium Range as channel flow that occurs along Nares Strait in northeast Greenland. These The Copernicus Climate Change Service Co-authors Weather Forecasts (ECMWF), using (C3S) includes in its product portfolio, J Portilla (EPN), L Cavaleri (ISMAR) spectra from 1979 to 2015. The basic weather systems play important roles reanalyses and a climate monitoring information developed are directional in the local weather and climate as well facility. These two products are being The ocean wave spectrum contains spectral statistics defining the local as forcing sea ice and ocean currents used to monitor the climate by providing detailed information of the energy wave systems. In addition, per wave that are important to the global climate monthly updates on the climate for density distribution over the frequency system, we derive Hs distributions, system. several ECVs. The monthly updates are direction domain. Although it is the their monthly variability, crossing- The current generation of global posted onto the Copernicus website fundamental working variable in state-of- sea probabilities, wave age, and wind atmospheric reanalyses have proven within a few days of the end of each the-art wave modelling and measuring statistics. From this basic information a to be important tools in furthering our month. Currently, the main sources of techniques, its use in practical and very comprehensive understanding of the understanding of these orographic content are the ERA-Interim and ERA5 scientific applications is still too limited. local meteorological and wave conditions winds and their role in the climate global reanalyses. Most applications only use integrated can be attained. This atlas is available at system. However, there is evidence that parameters as standard, neglecting http://www.modemat.epn.edu.ec/#/nereo

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 157 Section 5 the mesoscale characteristics of these The Mediterranean region variability Cendrawasih Bay (CB) is one of among systems may be missed in the current is characterised by several regional the largest bay in Indonesia which open The Relationship between Boreal generation. Climate Modes. Some among these, as directly to the north of Papua seas and summer Intra-seasonal the Western and Central Mediterranean it has complex interaction between air Here contrast and compare the Oscillation and the Stratospheric Mode (WMM) or the Mediterrenean and sea. However the understanding representation of these weather systems Circulation Dipole Mode (MDM), are characterised about CB the research of oceanography- and their associated air-sea heat fluxes in from indexes obtained from the climatology still very limited yet. Author Yayoi Harada the current generation ERA-I (horizontal Mediterranean SST anomalies. Others, resolution ~75km), the next generation The purpose of this study is to analyse Affiliation Meteorological Research as the Mediterranean Oscillation (MO) or ERA5 (horizontal resolution ~25km) the pattern and variability of CB current Institute/Japan the Western Mediterranean Oscillation and the ECMWF’s current operational and its correlation with the wind. The meteorological Agency (WMO), are monitored from indexes analysis (horizontal resolution ~9km) ocean current data for this research Co-author obtained from atmospheric (SLP) fields. during January and February 2016, the used the result of INDESO model and Y. Harada (Meteorological Research period of overlap of the three datasets. In the work to be presented we compare winds from ECMWF during 2008 until Institute/ Japan meteorological Agency) This comparison shows an improvement the characteristics of these modes 2014. Ocean current data is validated in the representation of these weather obtained from different Reanalysed with current measurement at the bouy in Boreal summer intra-seasonal oscillation systems with additional details as to their fields (ERA-40, Had ISST2 in one case the near in CB’s mouth and the result is (BSISO) is a phenomenon that active mesoscale structure and that of their NCEP, ERA-40 and ERA-20C in the reasonably good. convective region migrate northward in associated air-sea interaction present other also compare their impacts on the the Indian Ocean and the western Pacific The ocean current and wind that have at higher horizontal resolution. This precipitation and the temperature fields with a period of 30 – 90 days. In this been monthly averaged and the results suggests that our understanding of the of the neighbouring regions (CRU and study, statistical relationships between show both have almost the same pattern. impact of these wind systems on the U Delaware reanalysis). We also identify BSISO and the stratospheric circulation On Boreal Winter the pattern of wind and coupled climate system can be enhanced potential predictability fron the seasonal are examined focusing on the variabilities current moved to the east dominantly through the use of higher resolution teleconnections of these modes with the of the zonal wind fields both in the while in boreal summer moved to the atmospheric datasets. midlatitudes or tropical variability. troposphere and stratosphere. BSISO west with high velocity. On boreal spring index based on Kikuchi et al. (2012) and the pattern of wind and current create the Japanese 55-year Reanalysis (JRA- The Mediterranean Climate The pattern and variability of transition from boreal summer to boreal 55, Kobayashi et al. 2015) are used for Modes: their seasonal variability, current in the Cendrawasih Bay winter. However on boreal fall the pattern composite analysis. of wind and current same as boreal winter. impacts and predictability from and their correlation with wind To represent the zonal mean fields, the The current variability in this area showed renalysed fields. Author Thomas Simarmata mass-weighted isentropic zonal mean that the zonal and meridional component (MIM) Method (Iwasaki 1989) is applied Author OrtizBevia Maria J. Affiliation Bogor Agricultur of both current and wind have high to JRA-55. The MIM method is suitable University Affiliation University of Alcala spectrum value at the period 10.5 monthly for the examination of zonal momentum Co-authors Co-authors (annual fluctuation). however, wind budget, and enables analysis of a single OrtizBeviá María J. (university of Alcalá), Simarmata Thomas (Bogor Agricultural spectrum have inter-annual fluctuation hemispheric cell, such as Blewer-Dobson RuizdeElvira A. (University of Alcalá), University)Purba Mulia (Bogor with period 21 monthly while current circulation in the stratosphere and the Alvarez-García F. J. (university of Alcalá) Agricultural University)Atmadipoera Agus spectrum have period of 5.6 monthly. extra-tropospheric direct circulation. (Bogor Agricultural University)

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 158 Section 5

In order to extract variability monsoon trough over South Asia by west-east shifts, probably suggesting synchronized with BSISO or lower Trends and Tele-connections 2-30 of longitudes and the North Pacific that the recent trends may be a part of (higher) frequent variability than among South and East Asian Subtropical High (NPSH) over East Asia natural climate variability BSISO, temporal filtering based on Monsoons: Evidences through by about 5-70 of longitudes. Duchon (1979) is also carried out to NCEP-NCAR and CMIP5 Data While the west Indian Ocean SSTs the zonal mean fields obtained by the Use of reanalyses in climate appear to be related with summer application of the MIM method. We Author Ramesh Kripalani monitoring and research for the monsoon rainfall over northern parts found some characteristic features cocoa industry Affiliation Indian Institute of Tropical of India and North China, and may be of the zonal wind field during the Meteorology instrumental in the decreasing trend Author Alina Gainusa-Bogdan significant BSISO: Hemispherically Co-authors in the summer monsoon rainfall over symmetric westerly anomalies are Affiliation Rockwinds B. Preethi (Indian Institute of Tropical northern parts of India and over North observed from mid-troposphere up to Co-authors Meteorology), M. Mujumdar (Indian China, SSTs over the West Pacific Ocean the tropical tropopause layer (TTL) just A Gainusa-Bogdan (Rockwinds, Institute of Tropical Meteorology), A. (WPO) appear to be related with summer after the northward migration of active Bordeaux, France), A Diedhiou (National Prabhu (Indian Institute of Trpical monsoon rainfall over southern parts of convective region in BSISO region, and Research Institute for Sustainable eteorology) India and over South Korea-Japan sector. move poleward in both hemispheres in Development (IRD), France) spite of meridional asymmetry of the Recent trends and tele-connections Thus the increasing trends over these Providing gridded, global coverage convective activity: In the extra-tropical in the summer monsoon rainfall over regions may be related with SSTs over over long, uninterrupted periods of upper stratosphere of the Northern South and East Asia are examined for the WPO. Outputs from the Coupled time for a wide array of variables with Hemisphere, both easterly anomalies and the observational period 1970-2014. Model Inter-comparison Project Phase physically-consistent fields, reanalyses positive potential temperature anomalies Trend analysis indicates that over 5 (CMIP5) are investigated using are an extremely valuable source of are statistically significant during the South Asia one contiguous region over historical simulations (1861-2005) and data for operational climate monitoring northward migration of active convective northern part India exhibits a significant future projections (2005-2100) under and applied research for the agricultural region. decreasing trend and another region the RCP4.5 scenario. In spite of large spread among the CMIP5 models, future sector. The cocoa trading company Moreover, our results also reveal that over the southern part of India exhibits projections in the summer monsoon Rockwinds has been using the NCEP/ the amplitude of BSISO is extraordinarily a significant increasing trend in the rainfall over South as well as East Asia NCAR reanalysis to monitor and gain large during the strong low-frequency summer (June through September) indicate a multi-decadal variability, new insights into the development of easterly anomalies at around the 20 monsoon rainfall. displaying certain epochs of more rainfall the harmattan over West African cocoa hPa level associated with quasi-biennial However over East Asia two regions over South Asia than over East Asia and regions over the last three harmattan oscillation (QBO) and suggest influence one over the Korea-Japan peninsula vice versa. seasons in order to better predict the of the stratospheric circulation on the and another over South China indicate a subsequent evolution of African cocoa activity of BSISO in the troposphere. significant increasing trend. Incidentally, Tele-connections between the South and crops. the summer monsoon rainfall over North East Asian monsoon rainfall also exhibits Besides numerous merits, the NCEP/ China also indicates a decreasing trend. a multi-decadal variability with alternate NCAR operational product also has some Furthermore analysis of SSTs, MSLP and epochs of strengthening and weakening drawbacks, one of the most obvious winds at lower troposphere indicates that relationship. Furthermore large-scale ones being its coarse spatial resolution, the entire monsoon flow appears to have circulation features such as the monsoon of major concern for analyses targeting shifted westwards, with the low pressure trough over South Asia and the NPSH depict an oscillatory behavior with east- the relatively narrow African cocoa belt.

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 159 Section 5

It is thus with great interest that the interim reanalysis with the step of regular and east toward north-west and west (Meteorological Institute, University release of several years of the new, high- grid of 0.7 degrees: the daily fields of and reach up a minimum (20-40%) in Bonn, Germany), Susanne Crewell resolution ERA5 data is expected in June temperature of air at the level of a 2 m Carpathians. (Institute of Geophysics and Meteorology, 2017. and intensity of precipitation. University of Cologne, Germany) The south areas shown the frequency We will carry out spatial and temporal For verification of ERA-interim of HTC, which respect to drought of any The ongoing energy transition causes analyses, as well as inter-variable data concerned to the real rows of intensity, over more then 80% of months major challenges for many stakeholders correlation analyses of ERA5 data temperature and precipitation, a cross- in warm season. In the south Steppe due to the spatiotemporal inhomogeneity compared to NCEP/NCAR during correlation analysis was performed the frequency of months with the severe of renewable energy sources: (1) The harmattan season over West Africa for for the daily data of temperature and drought (HTC<0.5) is about 60-70%. transition system operator is challenged multiple harmattan-related variables intensity of precipitation for eight stations Frequency of extreme drought (HTC<0.3) to ensure the balancing between (relative humidity of air near the surface, of Ukraine and proper reanalysis fields. reach up 20-40% for the south areas, in energy supply and energy demand. wind velocity and the difference between For the air temperature the correlation other regions its occurrence does not (2) The distribution system operator daily minimum and maximum near- relations are very high, especially exceed 10-20%. is challenged to provide the required surface temperature). For variables during the cold period. For Kyiv, L’viv, infra structure from centralized to de- affecting cocoa crops all throughout Vinnytsya and Kirovohrad the coefficient Validation of COSMO-REA6/2 in centralized electricity generators. (3) The the year, like temperature, soil humidity of correlation is about 0.97-0.99 and spot market participants are challenged and precipitation, analyses will span reduced in summer time. respect to renewable energy by dealing with volatile energy supplies. the full time series and, in the case of applications For precipitation the correlation In order to overcome these problems it precipitation, other, gauge and satellite- relationship is worst. For most stations Author Christopher Frank is crucial to know where, when and to based data sets will be considered for the coefficient of correlation has the what extent renewable energy can be comparison. Affiliation University of Cologne annual course with maximum in February generated. Co-authors or March (0.64-0.72) and minimum in Christopher Frank ((Hans-Ertel-Centre for Atmospheric reanalyses offers July-August (0.45-0.58). The greatest Using the reanalysis data for Weather Research, Climate Monitoring interesting opportunities for a posteriori correlation coefficients are observed assessment of drought condition and Diagnostics, Germany),(Institute of studies, since they provide all relevant for Kyiv, Lviv, Vinnytsya. The lowest in Ukraine Geophysics and Meteorology, University meteorological quantities in a gridded coefficients calculated for Odessa and of Cologne, Germany)), Sabrina Wahl and consistent way. Especially, high- Author Inna Semenova Simferopol’, where the precipitation ((Hans-Ertel-Centre for Weather resolution reanalyses with gird sizes of regime featured by the closeness of Affiliation Odessa State Research, Climate Monitoring and a few kilometers allow detailed studies sea area. Using the monthly sums of Environmental University Diagnostics, Germany),(Meteorological on small scale variability. Therefore, temperature and precipitation the HTC Co-authors Institute, University Bonn, Germany)), Jan we provide an evaluation of regional was calculated for each grid point of I. Semenova (Odessa State D. Keller ((Hans-Ertel-Centre for Weather reanalyses with respect to renewable study area taken the period of April- Environmental University) Research, Climate Monitoring and energy related quantities such as wind October in 1995-2012. Diagnostics, Germany),(Deutscher speed and solar energy. Selyninov’ hidrotermal coefficient (HTC) The spatial distributing of HTC showed Wetterdienst, Offenbach, Germany)), This work focuses on two high resolution is usually calculated locally from data that over 80% months of warm season Bernhard Pospichal (Institute of reanalyses developed within the Hans- of temperature and precipitation for the are relatively dry at most territory of Geophysics and Meteorology, University Ertel Centre for Weather Research of network of the meteorological stations. Ukraine. Frequency of all criteria of of Cologne, Germany), Andreas Hense the German Weather Service (DWD). In study was used information of ERA- HTC<1.0 diminishes from south-east

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 160 Section 5

The high resolution reanalyses COSMO- Grant KMIPA 20156180 and by the Basic products, essential part of the work is REA6 (6 km horizontal resolution, 40 Variations of drought index with Science Research Program through the the verification of the forecasts for which vertical layers) and COSMO-REA2 (2 km different reference periods National Research Foundation of Korea the ECMWF reanalysis data plays an horizontal resolution, 50 vertical layers) funded by the Ministry of Science, ICT & important role. are based on the operational numerical Author Myoung-Jin Um Future Planning (2015R1C1A2A01054800) In this work, we describe the six- weather prediction model COSMO. REA6 Affiliation Yonsei University Keywords Drought Characteristics, week climate outlooks developed and covers Europe and the Mediterranean Reference Period, SPEI Co-authors tested in the CLIPS project during the region (CORDEX EUR-11 domain), REA2 M.-J. Um (Yonsei University), Y. Kim summer season 2017 and show the first is limited to Germany and its neighboring (Yonsei University), D. Park (Konkuk Verification of six-week verification results. regions. University) forecasts in Finland with The coarser reanalysis is available for The objective in this study is reanalysis data two decades from 1995 to 2014 and the Vulnerability Modeling of World understanding how much the drought Heritage Sites to Climate change finer from 2007 to 2013. Both reanalyses indices are changed due to the different Author Natalia Korhonen are generated with a nudging scheme to reference periods. We focused on the Affiliation Finnish Meteorological along the coast of Kenya Using assimilate observations. In this quality effects of drought characteristics, such Institute multi-temporal MODIS data assessment, independent observations as trends and frequency, for historical Co-authors of global radiation provided by the Author Yves Yves periods (1901-2014) with the standard N. Korhonen (Finnish Meteorological Baseline Surface Radiation Network Affiliation Institute of Remote precipitation evapotranspiration index Institute), O. Hyvärinen (Finnish (BSRN) are used. For wind speed Sensing and Digital Earth (SPEI) and used the datasets of the Meteorological Institute), T.K. Laurila evaluation 10m above ground SYNOP climate research unit (CRU) and the (Finnish Meteorological Institute), A. Co-authors observations serve as verifying “truth”. University of Delaware (UDEL). Vajda (Finnish Meteorological Institute), Yves Hategekimana(Remote Sensing Of Vertical wind profiles are compared to H. Gregow (Finnish Meteorological Non-renewable Resources Laboratory, measurements from two meteorological We chose the three cases of reference Institute) Institute of Remote Sensing and Digital masts in Jülich and Hamburg (Germany). periods, such as Ref 1 (1901–2014), Ref Earth, Chinese Academy of 2(1901-1957 and 1958–2014) and Ref 3 The evaluation shows that while Since June 2017, novel six-week climatic Science),Yueping Nie (Remote Sensing (1901-1957) and estimated the SPEI to forecasts are produced operationally Of Non-renewable Resources Laboratory, the regional reanalyses have some investigate the statistical differences. deficiencies, they show significant at the Finnish Meteorological Institute Institute of Remote Sensing and Digital We found that drought characteristics, (FMI) in CLIPS project (CLImate services Earth, Chinese Academy of Science),Yu improvements for radiation and wind particularly the severity and spatial speed scale dependent correlations supporting Public activities and Safety, Lijun(Remote Sensing Of Non-renewable extent, were different depending on the http://clips.fmi.fi/?lang=en). The main Resources Laboratory, Institute of compared to global reanalyses such as reference periods. Although we used only ERA-Interim. emphasis is to support the Finnish Remote Sensing and Digital Earth, two global datasets (CRU and UDEL), we public in planning their activities by Chinese Academy of Science) suggest that the reference period should co-designing and piloting the products be carefully chosen to estimate the together with the end-users community. The Coastal counties of Kenya have statistical drought indices. It is clear that the provision of usable numerous historical and archaeological sites, many of which are closely linked to Acknowledgement This study was forecasts especially at high-latitudes the development of the Swahili culture in supported by the Korea Meteorological is a challenging task. To examine the East Africa. Administration R&D Program under accuracy and usability of the developed

ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 161 Section 5

These sites consist of mosques, tombs, in each grid point of the model, that is resource information and, hence, to mounds and old city houses. Today, Wave resource assessment function of wave frequency and direction. boost new renewable energies markets some of the former trading settlements for the development of wave Waves are forced by surface wind in developing countries. As part of have become important business centers energy sector stress and, in open boundary regions, this effort, a global wind atlas master such as Mombasa, Lamu, Kilifi and depend also on the propagation of waves plan has been designed by the WB in Malindi. Many of the historical sites have Author Gianmaria Sannino originated from outside the region. partnership with Danish Technology designated as National Monuments and Affiliation ENEA University (DTU). In this case, in order to perform wave Reserves under the Cultural Heritage Act Co-authors simulations, besides surface forcing The project will update existing DTU of 2006. In addition to this Fort Jesus in G. Sannino (ENEA), A. Carillo (ENEA), represented by wind components, the Global Wind Atlas (GWA) with an Mombasa, Lamu Old Town and Sacred M.V. Struglia (ENEA) entire spectra of incoming waves along improved modeling stream which will Mijikenda Kaya Forests, both located on the boundaries are needed. In this work incorporate latest Reanalysis datasets the coast are recognized as UNESCO The growing interest in the Blue Energy we present a very high-resolution wave and a complete mesoscale model World Heritage sites. sector represents an opportunity for resource assessment in a region of the downscaling. The new GWA project will the sustainable growth of maritime These centers and the historical sites Mediterranean Sea, forced at the surface undertake a global level meso-scale economies, the sustainable development serve as important attractions for the and laterally by ERA-Interim reanalysis. modelling to 3km resolution which will of marine areas and the sustainable tourist industry but little are known and The 10-year simulation has been be be achieved with WRF atmospheric use of marine resources. Among them their fate uncertain due the climate performed using SWAN (Simulating Wave modelling stream. Mesoscale modellers the wave energy sector can play an change such internal and external factors Nearshore) model. Vortex will be responsible to map the important role in the clean energy and being at coastline. Vulnerability index world’s wind resource ant to produce the economy, as it is very abundant, diffuse employs different variables such wave global mesoscale layer of wind and other and renewable. height, Sea level rise, tide range, sea World Bank New Global Wind meteorological variables. surface all crucial to understand impact Its exploitation is based both on Atlas project powered by A further downscaled will be conducted of climate change with climate reanalysis technological research aimed to the Copernicus Reanalysis by DTU to under the kilometre resolution data. The results show both Lamu and development of new efficient devices, Author Gil Lizcano using and WAsP model and derived Mombasa as high vulnerable regions. and on the accurate assessment of generalized wind climatologies. The GIS and Remote sensing analysis were the resource. In this view, a complete Affiliation Vortex atlas will have an interim version to be employed to extract intrinsic attribute of statistical characterization of waves is Co-authors released in November 2017 which will the coast in this study area. Keywords: essential both to optimize the design of O. Lacava, Vortex, P. Casso, Vortex, be built using ERA Interim Reanalysis as Suitability Modeling, Climate Reanalysis the wave energy converter devices and A. Bosch, Vortex, A. Hahmann, DTU, large scale conditions. The final version Data, MODIS data, World Heritage, to estimate in advance the productivity J. Badger, DTU, R. Whiting, Everoze which is scheduled to go live by the end Kenya. of a site. Available observations, either of 2018 will incorporate ERA5 Copernicus buoys or satellites, are inadequate to Good wind data is critical to getting Climate Change Service (C3S) Reanalysis statistically characterize the resource in more wind projects built, and in turn as drivers. specific sites, therefore the use of high- helping to ensure access to affordable, resolution wave models is mandatory. reliable, sustainable and modern energy for all. With this intention, World Bank Wave models of third generation are (WB), through the ESMAP program, based on the evolution of the two- launched several initiatives to improve dimensional wave spectrum, defined access to quality of wind and solar

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The modelling will seamlessly interact with the existing GWA, helping develop a free access wind resource tool. At the same time the data will deliver real change on the ground, helping policy makers and project developers in developing countries get projects built. The engagement will also see the consortium deliver a wide spectrum of development support in a number of emerging economies, from country- level analysis and wind development zone identification through to individual bankable site assessment and due diligence review. The presentation will provide a description of the methodological approach based on the use reanalysis and mesoscale modeling technology and status of the project development. Focus will be given to the mesoscale model data production and preliminary results of the validations of the global 3km resolution wind resolution based in ERA Interim and ERA5 (reduced sample) downscaling.

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