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, International Conference on Reanalysis of reanalysis. As reanalysis datasets of all WCRP thematic areas: atmosphere, other types of analysis and models, (ICR5). We are delighted that we are become more diverse (atmosphere, land, ocean and cryosphere – Session inter-comparisons, diagnostics – all able to come together in Rome. ocean and land components), more organisers: Mike Bosilovich (NASA Session organisers: Franco Desiato This five-day international conference complete (moving towards Earth-system GMAO), Shinya Kobayashi (JMA), (ISPRA), 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, organisation 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 organisers: 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 organisers: 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 organisers: 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 NASA Global Modeling and Assimilation Office (NASA GMAO) (C3S-ECMWF) and Hugo Zunker 4.30–4.45pm R.05 Reanalysis at the Japan Meteorological Shinya Kobayashi (EC DG GROW Agency (JMA) 1.30–1.45pm W.03 Address from WMO/WCRP Deon Terblanche (WMO) 4.45–5pm R.06 Improvements in the Twentieth Century Laura Slivinski Reanalysis Version 3 (CU/CIRES & NOAA) 1.45–2pm W.04 Address from Italian Rep to WMO Silvio Cau (Director, Italian Meteorological 5–5.15pm R.07 CMA Global Reanalysis: Ziquan Liu Service) Status and Plans (CMA and NCAR) 2–2.30pm Invited Keynote Adrian Simmons 5.15–5.30pm R.08 The CMEMS global and regional ocean Marie Drevillon K.1 Reanalysis: Past, Present, and Future (ECMWF) reanalyses: towards a consistent set of high (Mercator Océan) resolution ocean reanalyses for operational 2.30–6pm Section 1 – Status and plans of reanalysis oceanography users and ocean state productions monitoring Chairs: Michael Bosilovich (NASA GMAO), Shinya Kobayashi (JMA), Simona Masina 5.30–5.45pm R.09 The CMCC Global Ocean Reanalysis Andrea Storto (CMCC) System (C- GLORS): a multi-purpose family (CMCC) of eddy-permitting ocean reanalyses 2.30–3pm Invited Talk Hisashi Nakamura R.01 On the Significance of Using High- (University of Tokyo) 5.45–6pm R.10 CERA-SAT: coupled reanalysis in the Dinand Schepers Resolution Sea-Surface Temperature in satellite-era (ECMWF) Atmospheric Reanalysis Production 6 –7.30pm Ice-breaker (drinks and finger food) 3–3.45pm Group photo and coffee break
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 3.15–3.30pm O.08 A Fundamental Climate Data Record Karsten Fennig of 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 Oceanography Centre) climate 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 Chairs: Magdalena Alonso-Balmaseda reanalyses (NASA 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 at ECMWF (ECMWF) 1985: large disagreements between five (BIRA-IASB) modern reanalyses 2.30–5pm Section 4 – Evaluation and intercomparisons of reanalyses 4.30–4.45pm E.06 Towards consistent diagnostics Michael Mayer Chairs: Franco Desiato (ISPRA), Masatomo of the coupled atmosphere and ocean (University of Vienna) Fujiwara (Hokkaido University), Sonia energy budgets Seneviratne (ETH), Adrian Simmons (ECMWF) 4.45–5pm E.07 Land surface precipitation and Rolf Reichle 2.30–3pm E.01 (Invited Talk) Results from the SPARC Masatomo Fujiwara hydrology in MERRA-2 (NASA/GSFC) Reanalysis Intercomparison Project (S-RIP) (Hokkaido University) during 2013-2017 5-5.45pm Invited Keynote Gil Compo K.3 Future Earth-System reanalyses: (CU/CIRES & NOAA) 3–3.15pm E.02 Assessment of upper tropospheric Sean Davis An atmospheric perspective and stratospheric water vapor and ozone (NOAA ESRL) in reanalyses as part of S-RIP 3.15–3.30pm E.03 Preliminary assessment of the ERA5 Rossana Dragani 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 with authors standing in front of poster (Met 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) 2–5pm Section 5 (continued) – 3.15–3.30pm A.08 On requirements for the application Frank Kaspar (DWD) Applications of reanalyses of reanalyses in the context of climate Chairs: Andrea Kaiser-Weiss (DWD), monitoring and energy applications Carolin Richter (WMO), Michel Rixen (WCRP), in Germany Jean-Noël Thépaut (C3S-ECMWF) 3.30– 4.15pm Coffee break 2–2.15pm A.02 Reanalyses’ use in operational Roberto Buizza weather forecasting (ECMWF) 4.15–4.30pm A.09 On the use of the 50-year high- Patrick Le Moigne resolution UERRA re-analysis for a hydro- (Météo-France) 2.15–2.30pm A.03 Stratospheric intrusion-influenced Katherine Emma meteorological application over Europe ozone air quality exceedances investigated Knowland (NASA in the NASA MERRA-2 Reanalysis GMAO) 4.30–4.45pm A.10 Development of long-term hydro- Rémy Bonnet meteorological reconstructions over France (CERFACS) 2.30–2.45pm A.04 Classification of Meteorological Allison Collow based on large scale atmospheric reanalyses Influences Surrounding Extreme Precipitation (NASA/GSFC) to study the multi-decadal variability of Events in the United States using the French river flows MERRA-2 Reanalysis 4.45–5pm A.11 From data mining to information Matteo De Felice 2.45–3pm A.05 Role of Southern Annular Mode Amita Prabhu (Indian extraction: using ERA-INTERIM reanalysis (ENEA) on Asian Monsoon: Mechanisms Institute of Tropical to model hydro-power production in Europe through NCEP-NCAR Reanalysis Meteorology) 5–5.45pm Invited Keynote Magdalena Alonso- 3–3.15pm A.07 Intercomparison of the near-surface Verónica Torralba K.4 Future Earth-System reanalyses: Balmaseda (ECMWF) wind speed trends in three reanalyses (Barcelona An ocean perspective Supercomputing Center)
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), Nick Rayner (Met Office) Carolin Richter (WMO), Michel Rixen (WCRP), 11.00 –11.15am S.03 Summary and key message Magdalena Alonso- Jean-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 characterisation Andrea Cipollone of eddy activities in a global ocean (CMCC) 11.15 –11.30am S.04 Summary and key message Franco Desiato (ISPRA), eddy-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 observations from the 1940s to the 1970s Keynotes Future Earth-System reanalyses: and then including satellite observations An atmospheric perspective to today. Author Gilbert P. Compo In the 21st century, these “full-input” Reanalysis: Past, Present Affiliation University of Colorado reanalyses have advanced, and and Future CIRES & NOAA, additional work has also generated reanalysis datasets using advanced Author Adrian Simmons Earth System Research data assimilation systems and only Affiliation ECMWF Laboratory, Physical Sciences Division surface observations that extend reanalysis back to the 1850s. These The development of the observing Co-authors accomplishments, though successful, system for weather and climate, and J.S. Whitaker (NOAA Earth System have still left several areas of great the origins, evolution, achievements Research Laboratory, Physical Sciences societal relevance in need of attention. and applications of reanalysis will be Division), P.D. Sardeshmukh (University Among these, for the complete period of reviewed. Future directions will be of Colorado at Boulder, CIRES & NOAA the instrumental record extending back indicated. Emphasis will be placed on Earth System Research Laboratory, to the 18th century, future reanalyses of some of the challenges that have been Physical Sciences Division), L.C. Slivinski the atmosphere need to achieve success encountered in undertaking reanalysis, (University of Colorado at Boulder, in providing reliable representation of presenting examples of the significant CIRES & NOAA Earth System Research the climate and variability of extreme progress that has been made and Laboratory, Physical Sciences Division), weather statistics; high impact weather discussing issues, longer-standing and P. Brohan (Met Office Hadley Centre), phenomena, such as tropical cyclones; emerging, that remain to be satisfactorily and R. Allan (Met Office Hadley Centre) and atmospheric trace gases and addressed. Broader institutional matters, aerosols. including international cooperation, will Since 1819, when Brandes followed up also be discussed. on his original 1816 proposal for making All of these should be determined from a “weather map” by retrospectively the surface of the earth to the boundaries analyzing the surface pressure over of space. Thoughts on the current status Future Earth-System reanalyses: parts of Europe for every day of the and possibilities for achieving these goals A land perspective year 1783, atmospheric “reanalysis” for datasets spanning the continually- has been a staple of weather and evolving instrumental record back to Author Sonia Seneviratne climate science. In the 20th century, Affiliation ETH Zürich Brandeis’s original reanalysis maps massive subjective reanalysis efforts of will be discussed. the early century were followed by the modern achievement of consistent data assimilation systems from numerical weather prediction being applied retrospectively to surface and upper-air
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 predictions. These primary challenges in Ocean reanalyses capabilities have gone our efforts to predict, mitigate and adapt a long way during the last decade, fuelled to climate change. Coupled earth system by advances in the ocean observing reanalyses offer a path to tackle these system, model and data assimilation critical questions. methods, availability atmospheric reanalyses, as well as concerted They should provide traceable inventories community efforts in production of transports, sources and sinks, and inter-comparison. involved in the primary climate cycles, and, in principle, they are powerful tools Nowadays ocean reanalyses are to optimise the use of observations. produced routinely by a number of But this is a major undertaking, paved institutions to monitor the ocean climate with new challenges, which will require and to initialize weather and climate major development in assimilation predictions. As the field advances, methodology, coupled modelling so are expectations and the potential and activities in data rescue. 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 years. The other is an additional product (to be completed early 2018) covers, Section 1 – Status (JRA-55CHS) with MGDSST data with State-of-the-art Atmospheric like ERA-Interim, the satellite period and plans of a 25-km resolution only over 28 recent Reanalysis at ECMWF from 1979 onwards. years. reanalysis products Author Hans Hersbach Monthly updates are provided and The comparison reveals substantial Affiliation ECMWF consolidated in an official release about differences in midlatitude atmospheric two to three months behind real time, On the Significance of Using processes around the western boundary Co-authors although preliminary data products High-Resolution Sea-Surface currents and associated SST fronts. Paul Berrisford (ECMWF), Gionata Biavati will be made available within a week Temperature in Atmospheric As a typical example, atmospheric (ECMWF), Per Dahlgren (ECMWF), of production. In a second phase Reanalysis Production response to variability of the Kuroshio Dick Dee (ECMWF), Rossana Dragani (production to start in 2018) a pre- Extension (KE) is examined. As in satellite (ECMWF), Manuel Fuentes (ECMWF), extension back to 1950 is planned. Author Hisashi Nakamura observations, enhancement of cloudiness Andras Horanyi (ECMWF), Joaquin ERA5 will provide a large number of Affiliation University of Tokyo and precipitation in the oceanic frontal Munoz-Sabater (ECMWF), Carole Peubey essential climate variables within the (ECMWF), Raluca Radu (ECMWF), Co-authors zone east of Japan during the unstable C3S Climate Data Store (CDS). regime of KE relative to its stable regime Iryna Rozum (ECMWF), Dinand R. Masunaga (Univ. Tokyo), H. Kamahori Compared to ERA-Interim, ERA5 is represented well in JRA-55CHS but not Schepers (ECMWF), Adrian Simmons (MRI-JMA), C. Kobayashi (MRI-JMA), incorporates many important innovations in JRA-55C product. The enhancement, (ECMWF), Cornel Soci (ECMWF), Jean- S. Okajima (Univ. Tokyo), T. Miyasaka that safeguard the provision of state- which results from augmented heat/ Noël Thépaut (ECMWF) and Sebastien (Univ. Tokyo), K. Nishii (Mie Univ.) of-the-art climate reanalysis. ERA5 is moisture release from the warmer ocean Villaume (ECMWF) Recent studies have identified distinct based on a recent version of the ECMWF with more active warm-core eddies, At the European Centre for Medium- impacts of the warm western boundary Integrated Forecast Model which comes to be better represented in Range Weather Forecasts (ECMWF), currents, such as the Gulf Stream and includes numerous improvements to the ERA-Interim after 2001, when the SST reanalysis is a key contribution to the Kuroshio, and associated midlatitude 4D-Var assimilation method as well as resolution was improved. Copernicus Climate Change Service frontal zones on the overlying the coupled atmosphere, ocean waves (C3S) that is implemented at ECMWF on atmosphere, including boundary-layer This oceanic thermal forcing onto the and land model. behalf of the European Commission. This wind/thermal structure, vertical motion atmosphere is manifested as positive presentation provides an overview of the and cloud-precipitation systems. correlation in anomalies between SST and heat/moisture release, which is latest ECMWF atmospheric reanalysis Their representation in reanalysis should represented only in the high-resolution ERA5, which is currently in production be sensitive to the resolution of SST MGDSST but not in COBE SST. As and will replace the widely used ERA- data prescribed at the lower boundary another example, stormtrack response to Interim reanalysis. of a forecast model, and the sensitivity meridional displacement of the Oyashio ERA5 is the fifth generation of ECMWF is assessed through comparison of two front is examined. Again, the positive atmospheric reanalyses of the global products of a new Japanese reanalysis correlation between anomalous SST and climate, which was pioneered with the (JRA-55). One is JRA-55C, in which heat/moisture release is much stronger in FGGE reanalyses produced in the 1980s, observed data have been assimilated in a JRA-55CHS, and so is the enhancement followed by ERA-15, ERA-40 and most forecast system with horizontal resolution of convective precipitation over warm recently ERA-Interim. Production is of ~60km and the COBE SST data with SST anomalies. taking place in two phases. A first phase 1-deg. resolution prescribed over 55
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 15 Section 1
key research priorities. This presentation product at an enhanced resolution. and aerosol observations as a weakly Earth System Data Assimilation will discuss various activities of the The presentation will conclude with an coupled assimilation system as a first and Reanalysis Efforts MAPP Program to advance Earth system outlook on plans for the next ECMWF step toward GMAO’s longer term goal of Supported by the NOAA Climate DA and reanalysis. C3S reanalysis, ERA6. developing an integrated Earth system analysis (IESA) capability that will couple Program Office’s MAPP Program Radiative forcing data are used that assimilation systems for the atmosphere, represent the observed evolution of Author Annarita Mariotti Status and plans for reanalysis ocean, land and chemistry. greenhouse gases, volcanic eruptions, Affiliation NOAA Climate Program at the NASA Global Modeling ozone and aerosols, and consistent and Assimilation Office The GMAO strategy is to progress Office – MAPP Program boundary conditions are used for sea- incrementally toward an IESA through an Co-authors surface temperature and sea ice. A Author Ron Gelaro evolving combination of coupled systems H. Archambault, and D. Barrie (NOAA number of reprocessed data records Affiliation NASA, Goddard Space and offline component reanalyses driven Climate Program Office – Modeling, are ingested as well as several data Flight Center (GSFC), Global Modeling by, for example, MERRA-2 atmospheric Analysis, Predictions, and Projections) sets that have never before been used and Assimilation Office (GMAO) forcing. Most recently, the GMAO Program in reanalysis. ERA5 is able to assimilate has implemented a weakly coupled Co-authors data from the latest instruments. assimilation scheme for analyzing ocean The Modeling, Analysis, Predictions, S. Pawson (1), A. da Silva (1), Observation bias correction schemes skin temperature within the existing and Projections (MAPP) Program is a W. Putman (1), W. McCarty (1), have been extended and improved. atmospheric analysis. competitive grants program in the NOAA A. El Akkraoui (2,1), S. Akella (2,1) Office of Oceanic and Atmospheric ERA5 is produced at considerably 1: NASA Goddard Space Flight Center, The scheme uses background fields from Research Climate Program Office that higher resolution than ERA-interim: Greenbelt, MD, USA, 2: Science Systems a near-surface ocean diurnal layer model supports data assimilation (DA) and new hourly analysis fields are available at a and Applications, Inc., Lanham, MD, USA to assimilate surface-sensitive radiances techniques for reanalysis as part of its horizontal resolution of 31 km on 137 plus in-situ observations along with all Reanalysis plays a critical role in GMAO’s core mission. levels in the vertical. Data products other observations in the atmospheric goal to enhance NASA’s program of include information about uncertainties assimilation system. In addition, MERRA- Recently, the MAPP Program funded Earth observations, providing vital generated by a lower-resolution (62 km) 2-driven simulations of the ocean (plus a set of projects to evaluate and data sets for climate research and the 10-member 4D-Var ensemble. A number sea ice) and atmospheric chemistry (for improve aspects of NOAA’s reanalysis development of future missions. As the of new parameters, such as 100-metre the EOS period) are currently underway, for climate monitoring and prediction, breadth of NASA’s observations expands wind speed and direction, are available as is the development of a coupled with the investigators leading these to include multiple components of the as part of the output, based on user atmosphere-ocean assimilation system. projects constituting the MAPP Climate Earth system, so does the need to requirements and identified gaps in Reanalysis Task Force. assimilate observations from currently This talk will describe the status of these previous reanalysis productions. uncoupled components of the system in ongoing efforts and the planned steps Now, as NOAA moves toward a unified A database containing all ingested a more physically consistent manner. toward an IESA capability for climate modeling and DA framework to support observations, together with detailed research. monitoring and prediction of the Earth GMAO’s most recent reanalysis of the information about how they are used, system across timescales, the MAPP satellite era, MERRA-2, has completed is available to users. In addition, a Program has identified coupled DA and the period 1980-present, and is now dedicated ERA5 land component improved or new DA-based monitoring running as a continuing global climate will deliver a land-surface reanalysis products for the ocean, cryosphere, land analysis with two- to three-week latency. surface, and atmospheric composition as MERRA-2 assimilates meteorological
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 16 Section 1
of temperature analysis is, in particular, Additionally, the algorithms needed to Reanalysis at the Japan improved considerably over that of Improvements in the Twentieth represent sampling and model error, Meteorological Agency previous reanalyses. For variables and Century Reanalysis Version 3 covariance inflation and localization, have regions in which the forecast model has been updated in version 3 and have led Author Shinya Kobayashi large biases, however, there still remain Author Laura C. Slivinski to improved quantification of uncertainty. Affiliation Japan Meteorological large uncertainties in the represented Affiliation Univ. of Colorado’s Results with the previous system (version Agency trends due to the fact that degree of Cooperative Institute 2c) show that the uncertainty tends to be constraint on the model biases varies for Research in too low in data-rich regions, and too high One of the major issues in reanalysis with changes in observing systems. The Environmental Sciences in data-sparse regions; these effects are is temporal consistency extending upper and middle tropospheric humidity, Co-authors generally improved upon in the version over decadal and longer time scales. for example, shows spurious trends G.P. Compo (CIRES/NOAA), J.S. Whitaker 3 system. The new version also includes Improving temporal consistency in due to the fact that a dry bias tends (NOAA), P.D. Sardeshmukh (CIRES/NOAA) a bias correction to marine observations future reanalyses is essential for to diminish slightly as the number of prior to 1870, which is calculated offline improving operational climate services observations from satellite water vapour The international Twentieth Century and considers the particular ship from and advancement in climate research. channels increases. Reanalysis (20CR) project led by which the observation came. Results of For this end, the Japan Meteorological NOAA and CIRES provides global, testing this new bias correction and other To facilitate investigations on the Agency (JMA) conducted the Japanese subdaily weather estimates throughout improvements will be discussed. 55-year Reanalysis (JRA-55) for the credibility of low-frequency variability the troposphere stretching back over period from 1958 onward. JRA-55 has and trends represented in JRA-55, the 150 years. It assimilates only surface been produced with the TL319 version JMA Meteorological Research Institute pressure observations into the NCEP CMA Global Reanalysis: of JMA’s operational data assimilation has produced a reanalysis assimilating Global Forecast System constrained by Status and Plan system as of December 2009, and its conventional observations only, called sea surface temperatures and sea ice production has been continued on a JRA-55C, and an AMIP-type simulation, concentration. In addition, the ensemble Author Zhiquan Liu near-real-time basis. called JRA-55AMIP. Kalman filter data assimilation method Affiliation NCAR & China used in 20CR provides quantification of Meteorological Administration (CMA) This system features numerous These are produced with the same uncertainty around these estimates via improvements made since the previous numerical weather prediction system Co-authors the ensemble spread. Japanese reanalysis (JRA-25). JRA- as used for JRA-55, and they are made Lipeng Jiang, Tao Zhang, Jie Liao, 55 also incorporates several newly available together with JRA-55 products The new version 3 system incorporates Chunxiang Shi, Zijiang Zhou, Lijuan Cao, available observational datasets as the JRA-55 family. JMA is currently several improvements over the previous Kaixi Hu, Hui Jiang, Xiao Liang, Jingwei produced as a result of ongoing efforts preparing the next reanalysis, called the data set, version 2c, including a higher- Liu, Dong Si, Chenghu Sun, Mingyan to improve quality of past observations, Japanese Reanalysis for Three Quarters resolution model, a larger ensemble, and Wang, Shuang Yao, Yizhou Yin, Zhishen including homogenization of radiosonde of a Century (JRA-3Q), with the aim of more observations. Version 3 uses a more Zhang, Bin Zhao (CMA) temperature observations and producing a more improved reanalysis sophisticated data assimilation algorithm CMA started a global reanalysis effort reprocessing of satellite data at major and contributing to climate services and than version 2c, leading to a reduction of from early 2014, which aims to producing meteorological satellite centres. climate research. spurious trends in 6-hour precipitation 40 years (1979-2018) atmospheric and forecasts from version 2c. These improvements have made JRA-55 land reanalysis products (CRA-40) products considerably better than JRA- by 2020 and then continuing it as the 25 products; the temporal consistency operational climate analysis system for climate monitoring and service purposes.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 17 Section 1
The original plan was to produce CRA-40 These developments must rely on by upgrading CMA’s operational NWP The CMEMS global and regional continuous and high quality reanalyses The CMCC Global Ocean system of 2014. However, experimental ocean reanalyses: towards a and reprocessing time series, which go Reanalysis System (C-GLORS): tests in 2015 showed that the operational consistent set of high resolution up to real time. Both C3S and CMEMS a multi-purpose family of eddy- system could not produce reanalysis ocean reanalyses for operational reanalyses are used. permitting ocean reanalyses products with desired quality. The CMEMS reanalyses are different and oceanography users and ocean Author Andrea Storto After further testing and comparison, state monitoring complementary to the C3S reanalyses, it is decided in late 2016 that this first which first objective is to achieve the Affiliation CMCC generation CMA reanalysis will move Author Marie Drévillon accurate description of climate variability. Co-authors to NOAA’s GFS/GSI-based model and Affiliation Mercator Océan CMEMS reanalyses aim at a seamless S. Masina (CMCC and INGV), data assimilation system for atmospheric Co-authors connection with CMEMS real time A. Cipollone, D. Iovino (CMCC) component and recently released analyses and forecast, thus CMEMS K. von Schuckmann (Mercator Océan) An eddy-permitting global ocean NASA’s Land Information System (LIS) regional reanalyses particularly benefit P.-Y. Le Traon (Mercator Océan, Ifremer) reanalysis system is under continuous for land component. Thus far, more from both higher resolution and specific development at CMCC. The system is than 100 TB historical conventional and The Copernicus Marine Environment regional tunings. called C-GLORS (CMCC Global ocean satellite observations were collected. Monitoring Service CMEMS aims Particular efforts are put on reanalysis system) and implements a Some careful data evaluation and quality to deliver generic and reliable the processing of sea ice and 3DVAR data assimilation scheme to control were performed with emphasis information, derived from space and biogeochemistry components. CMEMS assimilate hydrographic profiles and on better usage of data from Chinese in-situ observations and from models assures the collections of “best quality” altimetry data, a nudging scheme for observing networks. – including forecasts, analyses and reanalyses – on the physical and input data and maximal use of multiple assimilating sea-surface temperature and Currently, a 10-year (2007/01-2016/12) biogeochemical state over the global observation systems, and, on the long sea-ice concentration data from satellite, Interim reanalysis is in production with ocean and the European regional term, aims at a fully consistent approach and a large-scale bias correction GFS and GSI-3DVAR at T574 spectral seas. One of the main requirements across global and regional reanalyses, scheme. resolution and shall be completed this organizing their interoperability, their from operational oceanography users The ocean model component is NEMO September. Preliminary evaluation of this inter-dependencies, and joint operations is to have long time series of data at 1/4 degree resolution coupled with the CRA-Interim product and future plan will closer to real time (a few months only) as a reference statistical and quality LIM2 sea-ice thermo-dynamical and be presented. with a systematic yearly update. framework. dynamical model. Here we present an Among those users, environmental historical perspective on the CMCC 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 through the development of operational CMCC seasonal prediction system, Ocean Monitoring Indicators (OMIs), to the latest release included in the and related error bars. Copernicus Marine Service catalogue
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 18 Section 1 and the participation to international Earth System approach. It comprises for a comprehensive integration of the inter-comparison activities. Applications coupled assimilation of atmosphere, Improving the representation of regional climate of the Arctic for 2000- of the reanalysis and process-oriented ocean, waves, sea ice and land surface the Greater Arctic with ASRv2 2012. analyses will be given as well, looking for observations provided by the modern- ASRv2 surface and pressure level instance at the effect of data assimilation day observing system. Author David H. Bromwich products are available at 3-hourly and on polar regions transports and eddy Affiliation Ohio State University At its heart sits a pioneering coupled monthly-mean timescales at NCAR. population, along with a detailed quality ocean-atmosphere data assimilation Co-authors ASRv2 has new features including higher assessment. Finally, future directions system (CERA) which couples a 3D-Var A.B. Wilson (1), L-S Bai (1), Z. Liu (2), resolution depiction in space (15 km including feasibility of updating the ocean assimilation system (NEMOVAR) to M. Barlage (2), C-F Shih (2), S Maldanado horizontal resolution), updated model system to hybrid ensemble/variational the ECMWF Integrated Forecast System (1), K.M. Hines (1), S-H Wang (1), physics including sub-grid scale cloud four-dimensional data assimilation and (IFS) 4D-Var atmospheric assimilation J. Woollen (3), B. Kuo (2), H-C Lin (2), fraction interaction with radiation, and a plans for eddy-resolving reanalyses will system at the outer loop level. T-K Wee (2), M.C. Serreze (4), dual outer loop routine for more accurate be given. and J.E. Walsh (5). 1: Ohio State data assimilation. Weakly coupled to this is a land surface University, 2: NCAR, 3: NOAA NCEP, analysis based on a combination of An evaluation of ASRv2 yields a CERA SAT: coupled reanalysis 4: University of Colorado-Boulder, optimal interpolation (OI) and simplified 5: University of Alaska-Fairbanks. superior reproduction of near-surface in the satellite-era Extended Kalman Filter (EKF). CERA- and tropospheric variables. Forecast The Arctic is in the midst of rapid Author Dinand Schepers SAT – projected to cover 8 years starting precipitation and downward radiative in 2008- is produced using a 10-member environmental changes, spurred fluxes demonstrate significant ECMWF Affiliation Ensemble of Data Assimilations (EDA) by amplified effects due to human improvement over ASRv1. The high- Co-authors system coupling an atmosphere at 60 activities and natural variability. Global resolution topography and land surface, Eric de Boisseson (ECMWF), Roberto kilometre resolution on 137 vertical levels atmospheric reanalyses that merge a including weekly-updated vegetation Buizza (ECMWF), Per Dahlgren (ECMWF), with an eddy-permitting quarter degree wide variety of surface, atmospheric and and realistic sea-ice fraction, thickness, Dick Dee (ECMWF), Yuki Kosaka (ECMWF, ocean model. satellite remote sensing data into gridded and snow cover depth resolve fine-scale JMA), Patrick Laloyaux (ECMWF) analyses have long been relied upon to processes such as topographically- In this presentation we present the investigate Arctic climate change and forced winds. The European Centre for Medium-Range CERA-SAT coupled assimilation accompanying variability during recent Weather Forecasts (ECMWF) is a key approach, features of the reanalysis data decades. However, changing observing Thus, ASRv2 is particularly suitable for player in the production of reanalyses set and a preliminary assessment of systems create issues for climate change detailed investigations of near-surface for climate monitoring as well as benefits of coupled data assimilation investigations. characteristics during the period of research. In line with the Earth system in the data-rich satellite-era. rapid Arctic change; and therefore, approach defined in the current ten This presentation introduces version 2 of complements the multi-decadal year strategy, ECMWF has developed a the Arctic System Reanalysis (ASRv2), a perspective of the global reanalyses. coupled assimilation system for ingesting multi-agency, university-led retrospective observations of ocean and atmosphere analysis (reanalysis) of the Greater Arctic in a coupled ocean-atmosphere model. (poleward of 45°N). ASRv2 uses blends of the polar-optimized version of the CERA-SAT is a pilot reanalysis of the Weather Research and Forecasting (Polar satellite-era -funded by the ERA-CLIM2 WRF) model and WRF three-dimensional FP7 project- aimed at progressing the variational data assimilated observations
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 19 Section 1
dry grass and high oil content in native such as surface winds and temperatures In this presentation, we will give an BARRA: a high-resolution plants. More broadly, benefits from the available every 10 minutes. Other output overview on what can be expected from Atmospheric Reanalysis for reanalysis are expected for land-use and variables include moisture, pressure, the service within the next years. In the 1990-2016 over Australia water management, primary industries, cloud cover, precipitation, evaporation, first phase, PRECISE products will be and the health, energy, defence, and energy fluxes, and soil water. Here based on the model system developed Author Chun-Hsu Su minerals sectors. we report on the implementation of in the pre-operational project UERRA Affiliation Bureau of Meteorology BARRA and preliminary evaluations, and (there will be separate presentations on To fully realise benefits, researchers, describe a range of its applications of UERRA, e.g. Ridal et al. and Undén et. Co-authors governmental agencies and industry immediate interest to meteorologists, al.). While UERRA produced data sets for N. Eizenberg (Bureau of Meteorology, are collaborating to add value to the fire and landscape managers, and other the period 1961-2015, PRECISE will fill Docklands, Australia), G. Kociuba (Bureau reanalysis data. BARRA is a 12-km members of the emergency management the gap throughout 2016 and early 2017. of Meteorology, Docklands, Australia), regional-scale reanalysis, nested within community. This includes the use of P. Steinle (Bureau of Meteorology, the required boundary and/or initial This will be followed by monthly updates reanalysis to create tailored fire weather Docklands, Australia), Dörte Jakob conditions provided by the coarse-scale in near real-time. Hence, PRECISE will products for the fire agencies. (Bureau of Meteorology, Docklands, ERA-Interim reanalysis, Operational SST offer a consistent RRA from 1961 to near Australia), Paul Fox-Hughes (Bureau and Sea Ice Analysis, and the Bureau’s real time. The onset of the operational of Meteorology, Hobart, Australia) offline soil moisture reanalysis. We use PRECISE – Production of a monthly updates can be expected in The Australian Bureau of Meteorology an unchanging atmospheric modelling regional Reanalysis for Europe early 2018. All data will be saved with has commenced a project to produce suite based on the UERRA (Uncertainties within the Copernicus Climate hourly resolution and will be freely in Ensembles of Regional ReAnalysis) available via the Copernicus Data Store a high-resolution 1990–2016 reanalysis Change Services covering the Australian continent and system used at the UK Met Office and (CDS). The production system will be the surrounding regions, including New the more recent version of the Unified Author Semjon Schimanke discussed in the presentation. Model used in the Bureau’s weather Here, we will focus on the challenges Zealand and parts of southeast Asia. Affiliation SMHI This reanalysis is in the following referred prediction systems. of producing the RRA operational in Co-authors near real-time. In the second phase, it is to as BARRA (Bureau of Meteorology A 4D deterministic variational data P. Undén (SMHI), M. Ridal (SMHI), planned to switch to a more advanced Atmospheric high-resolution Regional assimilation scheme is used to optimally L. Berggren (SMHI), P. Le Moigne system that will be developed while the Reanalysis for Australia). Production runs combine model physics with multiple (Météo-France), E. Bazile (Météo-France), operational production of the RRA carries commenced in March 2017. observations from aircraft, sondes, H. Schyberg (MET Norway), on during phase one. Jointly funded by fire and emergency surface observations and satellites. R. Randriamampianina (MET Norway) BARRA also consists of multiple The new PRECISE reanalysis system service agencies in New South Wales, PRECISE (Production of a regional Tasmania, Western Australia and South convective-scale (1.5 km) downscaling will be built on but extending from analyses driven by the 12 km system, for Reanalysis for Europe within the the UERRA system in several ways: Australia and with major co-contribution Copernicus Climate Change Services) by the Bureau of Meteorology, supporting fire services. Downscaling The horizontal resolution of the data can be performed anywhere in the is a Copernicus service that will be assimilation system will be enhanced this project supports high-quality launched under summer 2017. The goal assessments of risk and likelihood of regional domain. from 11 km to 5.5 km and also the of the service is to provide a regional vertical resolution will be increased from wildfires, in Australia known as bushfires. The temporal resolution of the output reanalysis (RRA) for the atmosphere over 65 to about 90 levels. The top of the These are frequent events during the analysis fields for both the regional Europe, which will be updated in near model will be raised to allow assimilation warmer months of the year, owing to and higher-resolution subdomains are real-time. the Australian climate, vast areas of generally one hour, with many fields
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 20 Section 1 of satellite radiances. Moreover, the the last decade. ECMWF hasproduced number of layers in the boundary layer several reanalyses of atmospheric will increase. composition (e.g. reactivegases, aerosols and greenhouse gases) under the EU The MESCAN surface analysis of funded GEMS and MACCprojects and temperature and humidity will be the Copernicus Atmosphere Monitoring integrated in the production reanalysis Service (CAMS). since no downscaling will be necessary. New input data sets will be tried These reanalyses use data assimilation and integrated and a number of new to combine satellite retrievals of observation types or instruments will atmospheric composition with state of be tested. The lateral boundary will be the art atmospheric composition models forced by the global ERA5 RA. to produce long, consistent datasets. In this talk we will show results from the The onset of the production with the new recent CAMS interimreanalysis which system ushers the second phase of the covers the period from 2003 to the service in, which is scheduled for 2019. present day andprovides analysis fields The RRA dataset will start in the early for CO, O and AOD. This reanalysis 1980’s and will be updated operational in 3 can, forexample, be used to evaluate near real-time. Details of the advanced recent trends (2003-2016) in CO, which system as well as the time schedule will aremainly caused by El-Nino (2015) be discussed. and land-use induced changes in biomassburning as well as trends Reanalyses of Atmospheric in anthropogenic emissions. Composition at ECMWF: We will also showresults from the from MACC to CAMS latest CAMS reanalysis which is being produced at themoment. Both reanalyses Author Antje Inness are based on a fully integrated approach Affiliation ECMWF combining both meteorology and Co-authors atmospheric composition in one data J. Flemming (ECMWF), R. Engelen assimilation system with the new CAMS (ECMWF), M. Ades (ECMWF), A Agusti- reanalysis being more comprehensive, Panareda (ECMWF), Z. Kipling (ECMWF), including many chemical species, S. Massart (ECMWF), M. Parrington aerosols and greenhouse gases. (ECMWF), M. Suttie (ECMWF), The new reanalysis also exploits various V-H. Peuch (ECMWF) interactions, such as the interaction In addition to meteorological reanalyses, between aerosol and radiation and the reanalysis data sets ofatmospheric interaction between the meteorology composition have been emerging in and the land biosphere model for CO2.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 21 2017) focus is on producing ensembles the DARE effort includes meteorological Section 2 – Data rescue activities to support of regional reanalyses for several stations in western and eastern Observations reanalysis and climate services: decades and estimating the associated Mediterranean, North Africa, the Middle for reanalyses the EU-funded UERRA and uncertainties in the derived data sets. East, the Balkans, central and eastern EURO4M projects approaches Both projects have a core component Europe and Scandinavia mostly for the of data rescue (DARE) of meteorological post-1950 period. and outcomes observations, while ensuring DARE Preparing Observations for The targeted variables have been air coordination to avoid duplicating efforts. Reanalysis Author Manola Brunet pressure, air temperature, dew-point, Author Nick Rayner Affiliation Centre for Climate In this contribution, we will provide relative humidity, cloud cover and wind Change Universitat detailed information about strategies, speed and wind direction (precipitation, Affiliation Met Office Hadley Centre Rovira i Virgili approaches and outcomes of the DARE snow-depth, fresh snow) at the hourly Dynamical reanalyses provide a complete Co-authors activities, including information about (daily and sub-daily) scales. where the recovered observations are representation of the observed state of P. Jones (2), A. Gilabert (1), P. Unden (3), ASRv2 products may be used to force freely accessible. Under the EURO M- the climate at a given point in time. The L. Ashcroft (1), J.R. Coll (1), A. Klein Tank (4) 4 other environmental models, verify DARE effort, about 2.7M station-values quality of that representation depends 1: Centre for Climate Change, University regional processes, or aid in the siting of daily (sub-daily) maximum and on many things, but it depends most Rovira i Virgili, Tarragona, Spain, of future observation networks. fundamentally on the observations 2: Climatic Research Unit, School of minimum temperatures and precipitation assimilated. In order to produce a Environmental Sciences, University of (sea level pressure) observations were reanalysis which represents the past East Anglia, Norwich, United Kingdom, recovered from observing sites in North variability and evolution of the climate 3: Sveriges Meteorologiska och African, Middle East and Mediterranean as faithfully as possible, a large amount Hydrologiska Institut (SMHI), Sweden, countries. of work is required to prepare the 4: Koninklijk Nederlands Meteorologisch The focus was placed on extending back observations before they can be used, Instituut (KNMI), Netherlands in time those key records that have the either to provide boundary conditions or In the last years and under the EU potential to complete as far as possible to be assimilated. funding support, two research projects the instrumental record, covering since This overview presentation will consider have significantly enhanced climate the second half of the 19th century up to the different types of work required data availability and accessibility from the present, while ensuring their quality. (e.g. data rescue, quality control, land surface stations over Europe and The dataset was made freely accessible homogenisation, uncertainty estimation) adjacent regions. through several international databanks and use specific illustrative examples and repositories. The EURO4M (European Reanalysis and from the physical domain (atmosphere, Observations for Monitoring) project Under the UERRA-DARE component, ocean and cryosphere) from both (2009-2013) was aimed at supporting about 9M (~178M) of station values satellite and in situ sources of observed timely and reliable climate services were recovered (gathered from open information. to monitor variations and change of data sources in Catalonia, Norway and European climate, while the UERRA Sweden) over European data-sparse (Uncertainties in Ensembles of Regional sub-regions for pre- and post-1950, while Reanalysis) ongoing project (2014- their quality and spatial homogeneity have also been ensured. In this case,
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 22 Section 2
systems and outdated file formats. It is well known that radiosonde data surface data only reanalyses) the overall Data Recovery Effort of Nimbus They lack any metadata standards and need bias correction before they can quality of the adjustments could be era Observations by the NASA each product is often written in its own be used for climate reanalyses. Most improved as well. proprietary file structure. This requires reanalyses rely on bias corrections GES DISC Comprehensive comparisons with creating metadata by reading the calculated offline using (semi)automatic available satellite data and reanalysis Author James E. Johnson contents of the old data files. homogeneity adjustment methods. data are provided. The potential Affiliation ADNET/NASA GES DISC One approach is to analyse subdaily The job is tedious and laborious, as impact of making radiosonde records time series of differences between Co-authors documentation may be incomplete, data consistent with reprocessed GPS-RO background forecasts of a previous Asghar Esfandiari (1,2), Emily Zamkoff files and tapes are sometimes corrupted, measurements in the 2006-2016 period reanalysis cycle (bg) and observation (1,3), Atheer Al-Jazrawi (1,4), or were improperly copied at the time is also assessed. The adjustments are records (obs) for break detection. For Irina Gerasimov (1,2), Gary Alcott (1). they were created. expected to significantly reduce the break adjustment, one can either use 1: Goddard Earth Sciences Data and rejection rate of radiosonde temperature again the bg-obs time series or one Information Services Center (GES observations as well as the biases of can use composites of neighbouring DISC), NASA GSFC, Greenbelt, MD, Homogenized radiosonde the resulting reanalyses such as the first radiosondes. United States. 2: ADNET Systems, temperature data for climate Copernicus climate reanalysis ERA5. Inc., Rockville, MD, United States. reanalyses Adjustments from both methods (called 3: KBR Wyle Systems, Inc., McLean, VA, RAOBCORE/RICH) have been used Author Leopold Haimberger United States. 4: Telophase Corporation, in many contemporary reanalyses Arlington, VA, United States. Affiliation University of Vienna assimilating these data. Since the last NASA launched seven Nimbus Co-authors major release of this data set in 2012 meteorological satellites in the 1960s and H. Hersbach (European Centre for Medium- several improvements could be realized, 70s. These satellites carried instruments Range Weather Forecasts, UK), P. Dahlgren most notably the adjustment of annual for making observations of the Earth (European Centre for Medium-Range variations of the radiosonde observation in the visible, infrared, ultraviolet, and Weather Forecasts, UK), S. Brönnimann biases, better adjustment of short time microwave wavelengths. The original (Oeschger Center for Climate Change series and of time series with gaps, data archive consisted of a combination Research, University of Bern, Switzerland) backward extension of adjustments to of magnetic tapes and various film S. Jourdain (Météo-France, France), Florian 1939 and forward extension to 2016. Ladstätter (Wegener Center for Climate and media. As these media are well past their Backward extension has been greatly Global Change, University of Graz, Austria) expected end of life, the valuable data facilitated by activities at ECMWF to A. Steiner (Wegener Center for Climate and they contain are now being migrated to convert upper air data collected within Global Change, University of Graz, Austria), the GES DISC modern online archive the EU FP7 project ERA-CLIM(2) into A. Sterin (Russian Research Institute for the so-called ODB format, which can The process involves recovering the Hydrometeorological Information, Russia), be directly read in by the Copernicus digital data files from the tapes as well A. Stickler (Oeschger Center for Climate reanalysis data assimilation system and as scanning images of the data from film Change Research, University of Bern, is convenient for other use cases as well. strips. This presentation will address Switzerland), M.A. Valente (Instituto Dom Due to availability of better reference the status and challenges of recovering Luiz, Faculty of Science of the University data (ERA-preSAT, JRA-55 and also the Nimbus data. The old data products of Lisbon, Portugal) were written on now obsolete hardware
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 23 Section 2
We shall present the overarching plans construction of marine climate records impact of any conversions on data The Copernicus Climate Change for service provision, and highlight the and in reanalysis. quality. Secondly a comparison of Service Global Land and Marine progress to date in creating an inventory duplicate observations originating from of data holdings from disparate available ICOADS provides open access to a the same original report, but subject to Observations Database: Plans surface marine data from a variety of and progress to date sources. We shall highlight an initial differences in data management, would forthcoming test release of the data and different platform types (including ships, enable an improved assessment of this Author Peter W. Thorne the schedule of further releases. The moored and drifting buoys and fixed contribution to data uncertainty. service must meet key stakeholder needs platforms) and importantly keeps the Affiliation Maynooth University Other anticipated benefits of if it is to be successful. Therefore we multivariate marine record together in Co-authors reprocessing include recovery of strongly welcome constructive feedback a common format. In recent years the C. Voces (Maynooth University), additional data and metadata and both during and after the event. Formal importance of identifying observations M. J. Menne (NOAA NCEI), E. Freeman improved consistency. channels for feedback will be highlighted. made on the same ship or platform (NOAA NCEI), R.J.H. Dunn (Met Office), has become more apparent as the D. Berry (NOC), A. Stephens (STFC) sophistication of error models for marine EUMETSAT Data Records The benefits for reanalysis of data has increased. Identification of the The Copernicus Climate Change Service in Support of Reanalysis Global Land and Marine Observations reprocessing the surface marine observations made on the same platform Database service aims to produce climate record is also a key requirement for reanalysis. Author Jörg Schulz Unfortunately the marine data in ICOADS improved surface meteorological data Affiliation EUMETSAT Author Elizabeth C. Kent contains many observations without holdings across domains, timescales, Co-authors and Essential Climate Variables. Affiliation National Oceanography identifiers as substantial amounts of Centre historical data were derived from sources C. Anderson (EUMETSAT), M. Doutriaux- Substantial efforts will be made to Boucher (EUMETSAT), T. Hanschmann integrate holdings, ensuring consistency Co-authors that had not retained ship identifier information. (EUMETSAT), Tim Hewison (EUMETSAT), across and between timescales (sub- D. I. Berry (National Oceanography V. O. John (EUMETSAT), A. Lattanzio daily, daily and monthly), and to improve Centre), E. Freeman (National Centers We will illustrate, using examples from (EUMETSAT), C. Marquardt (EUMETSAT), aspects of data discovery and access. for Environmental Information), a probabilistic trajectory estimation, R. Roebeling (EUMETSAT), F. Rüthrich S. J. Worley (National Center The data shall be served to users under how the methods used to combine (EUMETSAT), and T. Tabata (MSC/JMA) for Atmospheric Research) a common data model as a set of marine surface data from different historical archives can affect quality and EUMETSAT addresses climate fundamental data holdings suitable for The surface marine observational record consistency. Focussing on requirements monitoring by delivering advanced use in myriad applications, including is an important input data source for all for reanalyses, we will demonstrate how multi-satellite programmes with long- reanalyses. The service started in reanalyses. The observations are used reprocessing of historical marine surface term commitment, maintaining a unique March 2017 and, subject to satisfactory for assimilation, but for atmospheric data holdings would improve the quality archive of decades of space-based performance, shall run for four years with reanalyses are also used for construction of the marine climate record. observations, producing consistent incremental improvements in service of sea surface temperature gridded climate data records, providing easy provision over its lifetime. It brings analyses used as the lower boundary. A reprocessing would permit an improved access and supporting climate-related together a number of key European The International Comprehensive Ocean- quantification of uncertainty. Firstly a capacity building initiatives. This involves organisations together with sustained in- Atmosphere Data Set (ICOADS) is the review of the available documentation specific scientific and technical efforts kind collaboration with NOAA’s National most complete archive of surface marine and formats would provide additional Centers for Environmental Information. observations and is widely used in the information on data precision and the
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 24 Section 2 for the re-calibration of historical satellite addition, EUMETSAT is also providing In order to derive reliable long term have been inter-calibrated to the SSM/I data and the extraction of climate data Atmospheric Motion Vector data records trend estimates of the global water and instrument series to allow a seamless records. from Meteosat and AVHRR data that energy cycle parameters it is strictly continuation of existing TCDRs. have been consistently reprocessed for necessary to carefully correct for all In particular, the scientific analysis of In order to extend the available FCDR to the usage in re-analysis. known problems and deficiencies of raw satellite data leading to corrections the time period before the SSM/I epoch, the SSM/I radiometers as well as to of artefacts, improved calibration of The presentation will provide an overview CM SAF has now reprocessed available inter-calibrate and homogenise the individual instruments and harmonisation of EUMETSAT’s recent scientific and brightness temperatures from the SMMR different instruments. Moreover, all of several satellite instruments in a technical advances and prospects for (Scanning Multichannel Microwave applied corrections need to be clearly time series is fundamental to serve the providing useful satellite data records for Radiometer) on board Nimbus-7 with the documented to provide a complete generation of physically consistent data reanalysis. main focus on the inter-calibration of the calibration traceability for a Fundamental records of geophysical variables by brightness temperatures to the SSM/I Climate Data Record (FCDR). reanalysis or the application of retrieval series, using ERA20c as a transfer target. methods. With the participation in the EU A Fundamental Climate Data Following these recommendations, CM The re-processed data record will be ERA-CLIM, ERA-CLIM2 and FIDUCEO Record of SSM/I, SSMIS, and SAF released in 2013 a FCDR of SSM/I available in the same user friendly data projects EUMETSAT has developed SMMRbrightness temperatures brightness temperatures (DOI:10.5676/ format as the existing FCDR. The new dedicated capabilities and capacities EUM_SAF_CM/FCDR_SSMI/V001), freely FCDR release will also extend the SSMIS Author Karsten Fennig to deliver consolidated Fundamental available from the web user interface data record with two additional years. Climate Data Records useful for global Affiliation Deutscher Wetterdienst (http://wui.cmsaf.eu/). This FCDR has Altogether, the FCDR will now span the reanalysis. Co-authors already been used in the ESA CCI Sea time period from 1978 to 2015 combining Marc Schröder (DWD, Offenbach, ice project and will also be used in the observations from SMMR, SSM/I and The developments are utilised in support Germany), Axel Andersson upcoming reanalysis ERA5. In order to SSMIS. to the Copernicus Climate Change (DWD, Hamburg, Germany) further extend the HOAPS dataset in Service where EUMETSAT is delivering This presentation will focus on the time, the SSM/I successor instrument further consolidated data records for The satellite based HOAPS (Hamburg inter-calibration of the SMMR and the SSMIS (Special Sensor Microwave many of its own satellite missions but Ocean Atmosphere Parameters and evaluation of the combined FCDR over Imager Sounder) has to be used from also for satellites instruments from other Fluxes from Satellite Data; http://www. the complete time period. A validation 2009 onwards. space agencies ranging back into the late oaps.org/) climatology provides climate of the brightness temperatures is a 1970s. The instrument records addressed data records of precipitation, evaporation CM SAF also reprocessed the SSMIS challenging task as there are no ground- range from infrared and microwave and the resulting freshwater flux over sensors onboard F16, F17, and F18 to truth reference measurements available sounding and imaging, radio occultation the global ice-free ocean between the same standards as the SSM/I data for the microwave band. Hence, the to scatterometer instruments. 1987 and 2008. The latest version of record for the time period 2006 – 2013 homogeneity of the FCDR is evaluated by HOAPS has been released by CM SAF and the combined FCDR was released an analysis of the relative biases between For instance instruments considered for and is available from the CM SAFs web in 2015 (DOI:10.5676/EUM_SAF_CM/ the different instruments before and after infrared sounding range from historic user interface (http://wui.cmsaf.eu/). FCDR_MWI/V002). Amongst others, the inter-calibration offsets are applied. HIRS on NIMBUS-6 to the modern IASI The HOAPS climate data records are known instrument issues like sunlight on Metop platforms. For each of the primarily based on passive microwave intrusions, moonlight intrusions, and data records significant improvements measurements from the SSM/I (Special reflector emissivity have been accounted in calibration, multi-instrument time Sensor Microwave/Imager) sensor family. for and the brightness temperatures series harmonisation and/or uncertainty characterisation has been achieved. In
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 25 Section 2
exposition. In view of the already Observing Mass Variability in the available 15 years of data acquired by Earth System with the Satellite the GRACE mission and the prospect Gravity Missions GRACE and of a continuation of the gravity-based GRACE-FO monitoring of terrestrial water storage with GRACE-FO, which is scheduled for Author Henryk Dobslaw launch in February 2018, it is now very Affiliation Helmholtz Centre promising to attempt the incorporation Potsdam, German of gravity-based indicators into Research Centre for hydrometeorological re-analysis efforts. Geosciences 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 the 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. GRACE is therefore unique among the currently available remote sensing concepts since it is susceptible to mass changes independently of its surface
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), by these EDA systems. Some relevant targeting the era of global coverage by J. Muñoz-Sabater (ECMWF), specific scientific questions will be Author Patrick Heimbach satellite altimetry, the optimal state and and R. Radu (ECMWF) discussed as for example the spatial- Affiliation University of Texas parameter estimates fulfill conservation temporal variability of the reanalysis at 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 uncertainties in the verifying truth can Understanding the global full-depth analysis increments at regular periods prediction system and provides essential influence the validation of uncertainty ocean circulation, attributing its throughout the estimation process. added value to the users. Estimates evolution and changes on seasonal to of uncertainty are also important in estimation. Finally guidance will be given multi-decadal time scales, inferring its Closed property budgets so inferred reanalysis but are not provided with how this information can be best used for role in the global climate system, and provide valuable information for ocean all currently available data sets. At the the reanalysis user community. quantifying related uncertainties are and climate science. Remaining European Centre for Medium-Range systematic misfits or unphysical control hampered by sparse and heterogeneous Weather Forecasts (ECMWF) various Impact of Optimal Assimilation observations, an inherently turbulent adjustments point to either remaining reanalysis systems have been produced fluid, imperfect models, and uncertain model inadequacies or unrealistic to date, or are currently in production, Windows in Coupled Data forcing functions. uncertainty estimates. which includes uncertainty estimates. Assimilation on AMOC Analysis Viewed as a very large-scale estimation The sustained multi-decadal production This is possible by using the Ensemble of Author Shaoqing Zhang problem, the goal is to find an optimal effort by ECCO is entering a new phase Data Assimilation (EDA) technique. The Affiliation Ocean University state and parameter estimate through with a special emphasis on the ocean’s EDA system provides flow-dependent of China impact on, and the imprints from the fitting a state-of-the art circulation background errors for the data Co-authors interaction with the polar ice sheets, and model to all available observations assimilation system in the reanalysis, but Lv Lu, Xiaopeilin and Lixin Wu (Physical their role in global and regional sea level while fulfilling underlying conservation in addition, the spread of the EDA can Oceanography Key Laboratory of Ministry change. laws and equations of motion. To do so also be used for uncertainty estimates of of Education, Ocean University of China, we formulate a variational problem in the reanalysis products. ECMWF is in the and Qingdao National Laboratory for which a weighted squared model-data production phase of ERA5 (implemented Marine Science and Technology) misfit function is augmented by the by the Copernicus Climate Change model equations via Lagrange Multiplier Service on behalf of the European Climate signals are the results of Method. Commission) and has produced the interactions of multiple time scale media ERA-20C and CERA-20C reanalyses such as the atmosphere and ocean in the coupled earth system. Coupled data assimilation (CDA) pursues balanced and
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 27 Section 3 coherent climate analysis and prediction model error forcing term active in the component of MERRA-2 used a 3D-Var initialization by incorporating observations The ECMWF weak-constraint stratosphere above 40 hPa, and show scheme, which was operational at the time from multiple media into a coupled model. 4D-Var formulation and a results of assimilation trials using the of its design. Since then, a Hybrid 3D-Var ECMWF IFS atmospheric model. Results then a Hybrid 4D-EnVar were implemented, Given different time scales of comparison between 12 and 24 show improvements in the short-range adding an ensemble component to the characteristic variability in different hour assimilation window length forecast fits to observations, and this data assimilation scheme. media, an optimal assimilation window to produce recommendations for formulation of weak-constraint 4D-Var (OAW) exists for each medium. With a In this work, we will be examining the future reanalysis as part of the was made operational at ECMWF in simple coupled model that simulates benefits of using hybrid ensemble flow- ERACLIM2 project November 2016. typical scale interactions in the climate dependent covariances to represent system, we first show that an OAW in Author Jacky Goddard Attempts to extend the model error errors and uncertainties in historic each medium can provide maximal Affiliation ECMWF forcing to the rest of the atmosphere periods. Specifically, periods of pre- and observational information that best fits have so far been unsuccessful due to post-satellites, as well as periods of Co-authors characteristic variability of that medium problems with erroneous interpretation of active tropical cyclone seasons. P. Laloyaux (ECMWF), M. Fisher during the data belending process. aircraft observation error as model error. (ECMWF – retired), Y Trémolet Finally, we will also be exploring the use Characterising the statistical properties Then we apply the idea to a coupled (NCAR/UCAR), S. Lang (ECMWF) of adaptive localization scales. of model error is one of the main general circulation model and its data In most operational implementations current problems in the weak-constraint assimilation system to study the impact of four-dimensional variational data 4D-Var. Future work will aim to improve of OAWs on climate analysis by recovering A Method for Snow Reanalysis: assimilation (4D-Var) the strong- the specification of the model error important characteristic variability such The Sierra Nevada (USA) constraint formulation is used. This relies covariance matrix. We discuss results as sub-diurnal in the atmosphere and Example on the assumption that the numerical from an investigation into 4D-Var window diurnal in the ocean more accurately. model’s representation of the evolution length, 12 hour vs 24 hour, with both Author Manuela Girotto In particular, the features and variability of atmospheric flow is perfect, or at least strong- and weak-constraint 4D-Var. of Atlantic Meridional Overturning Affiliation USRA & NASA GMAO that the model errors are small enough to Circulation has been examined. Co-authors be neglected compared to other errors in Steven A. Margulis (Department the system. Using hybrid data assimilation for reanalyses of Civil and Environmental Engineering, As other aspects of data assimilation University of California, Los Angeles, processes have advanced, the validity Author Amal EL Akkraoui CA, USA), Gonzalo Cortés (Department of this perfect model assumption has Affiliation NASA-GMAO/SSAI of Civil and Environmental Engineering, become more questionable. It also limits Co-author University of California, Los Angeles, the length of the atmospheric analysis Ricardo Todling (NASA-GMAO) CA, USA), Michael Durand (School of window that can be used to roughly 12 Earth Sciences, and Byrd Polar Research hours. The Modern-Era Retrospective Analysis Center, The Ohio State University, for Research and Applications, version Columbus, Ohio, USA) Weak-constraint 4D-Var relaxes the 2 (MERRA-2) is the latest reanalysis perfect model assumption by explicitly produced by GMAO, and provides global This work presents a state-of-the art representing model error as part of the data spanning the period 1980-present. methodology for constructing snow water 4D-Var control variable. We present a The atmospheric data assimilation equivalent (SWE) reanalysis. The method formulation of weak constraint with a
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 28 Section 3 is comprised of two main components: hypotheses about the mechanisms ruling (1) a coupled land surface model and Atmospheric reanalysis for multi Paleoclimate reanalyses as a past changes or the compatibility of the snow depletion curve model, which centuries using historical tool to understand the signal interpretation of observations coming from is used to generate an ensemble of weather archives and isotopic recorded by observations over different sources. Examples are provided, predictions of SWE and snow cover proxies the past millennium in particular focusing on the temperature area for a given set of (uncertain) inputs, asymmetry between continents in both and (2) a reanalysis step, which updates Author Kei Yoshimura Author Hugues Goosse hemispheres over the last centuries, estimation variables to be consistent with Affiliation The University of Tokyo Affiliation Université de Louvain showing the role of the oceanic heat the satellite observed depletion of the storage and transport to explain the Co-authors ELIC/TECLIM fractional snow cover time series. delayed warming of the Southern Ocean P. Neluwala (The University of Tokyo), Data assimilation has attracted compared to other regions. This method was applied over the Sierra A. Okazaki (RIKEN) increasing interest in the paleoclimate Nevada (USA) based on the assimilation Our systematic instrumental measurement community over the past 15 years since of remotely sensed fractional snow for meteorological quantities only lasts the technique has several advantages A global climate reconstruction covered area data from the Landsat 5-8 100 years at most, so they are too short compared to the empirical-statistical using data assimilation record (1985-2016). The verified dataset to analyze recent big climate changes, approaches traditionally used to (based on a comparison with over 9000 Author Stefan Brönnimann like Little Ice Age or Medieval Warming reconstruct temperature or precipitation station years of in situ data) exhibited Period. In our research group, we have fields from paleoclimate records. Several Affiliation Oeschger Centre and mean and root-mean-square errors less made an offline data assimilation system issues still need to be addressed to Institute of Geography, than 3 and 13 cm, respectively, and for stable water isotopes and showed our obtain comprehensive reanalyses, one University of Bern correlation greater than 0.95 compared success to reproduce ENSO changes of the strongest constraint being the Co-author with in situ SWE observations. during 19th to 21st century (Okazaki and small number of observations, displaying J. Franke (Oeschger Centre and Institute The method (fully Bayesian), resolution Yoshimura, 2017). relatively large uncertainties. of Geography, University of Bern) (daily, 90-meter), temporal extent (31 On the other hand, we have made data Those records are generally only Understanding the past behaviour of years), and accuracy provide a unique assimilation of weather information from indirectly connected to standard the climate system ideally relies on a dataset for investigating snow processes. old diaries (Toride et al., 2017). Thus, by climate variables implying that inversion comprehensive view of past climate This presentation illustrates how the combining those two data assimilation techniques or adequate observation states. However, paleoclimatology is reanalysis dataset was used to provide a methods, we are trying to make multi- operators need to be included in often faced with a sparsity of proxies basic accounting of the stored snowpack centennial length atmospheric reanalysis the assimilation process. Specific and a comprehensive view is then only water in the Sierra Nevada over the last product. At the presentation, I’d like to adaptations to data assimilation possible with audacious interpretation. 31 years and ultimately improve real-time introduce these two new methods and algorithms are also required to deal with streamflow predictions. In recent years, new numerical current status of our multi-centennial the records that represent averages over techniques have become available that reanalysis project. periods ranging from a few months to derive a best estimate of the climate state several decades and are distributed over by combining the real-world information strongly spatially biased network. from sparse proxy data with the physics Nevertheless, existing simulations with of climate models. Such data sets data assimilation already provide useful provide a physically consistent, spatially reconstructions of the state of the system. They also provide a way to test
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 29 Section 3 complete picture of the past climate with the ionosphere models depends NOAA and discuss its preparation and At the same time, there are undesirable system that is in agreement with the on the comprehensive extension of challenges for assimilation of data with discontinuities in ocean heat content proxy records within their errors. data assimilation methods into the strong diurnal signals in the MLT region. and an excessive accumulation of Arctic Mesosphere and Lower Thermosphere sea ice. CERA-20C provides a ten- We present a 400-year long, monthly, (MLT). member ensemble climate reanalysis for global, 3-dimensional climate data Earth system climate reanalyses all parameters and levels over the 20th set that was produced by assimilating In this region of active wave dynamics at ECMWF century. Ensemble generation is based historical instrumental data, documentary and strong diurnal cycles the past (UARS) on the Ensemble of Data Assimilations evidence, and tree ring data into a large and present (TIMED, EOS-Aura) space- Author Patrick Laloyaux (EDA) system which explicitly accounts ensemble of climate model simulations borne observations of wind, temperature Affiliation ECMWF for errors in the observational record and using an off-line Ensemble Kalman Filter and tracers have been analyzed by Co-authors in the forecast model. This ensemble technique. In addition to evaluations models with the top lids placed between Eric de Boisseson, Per Dahlgren, technique aims to provide an indication and comparisons of this method with 80-100 km for case studies. The Dinand Schepers, Jacky Goddard, of the confidence in the data. existing reconstruction, we present relatively low positions of the model top Yuki Kosaka, Magdalena Balmaseda, analyses of this data sets with respect to lids and 6-hour assimilation windows Kristian Mogensen, Dick Dee, the transition of the climate system from preclude accurate analysis for diurnal Roberto Buizza (ECMWF) the Little Ice Age climate to the present and sub-diurnal upward-propagating climate. tides that deliver impacts of “terrestrial” The European Centre for Medium- perturbations and stratospheric climate Range Weather Forecasts is a key anomalies into the space weather/climate player in the production of reanalyses Reanalysis in the Whole domain. for climate monitoring and research. Atmosphere Models: From Following the Earth system approach Nudging Techniques to Data In this paper we discuss methods to embraced in the new ten year strategy, a constrain the dynamics and transport of coupled assimilation system that ingests Analysis in the Mesosphere and the multi-year WA predictions below the Lower Thermosphere simultaneously ocean and atmospheric stratopause using the 2007-2016 MERRA observations in a coupled ocean- Author Valery Yudin data to achieve the first outlook on the atmosphere model has been developing. day-to-day, annual and year-to year Colorado University, Affiliation variations of the mean flow, planetary This approach has been used to CIRES waves and tides. We will verify realism produce a new coupled 20th-century Co-authors of two WAM predictions of NOAA and reanalysis, called CERA-20C, which D. Kleist (NCEP/EMC), K. Howard NCAR constrained by MERRA by MLS, provides a long record of low-frequency (NCEP/EMC), T. Fuller-Rowell (CU/ TIDI and SABER observations along with climate variability using a consistent CIRES), S. Karol (CU/CIRES), R. Akmaev ground-based measurements. set of observations. First results (NOAA/SWPC), A. Kubaryk (NCEP/EMC). show that CERA-20C improves on The last decade (2004-present) the representation of atmosphere– The Whole Atmosphere Model (WAM) collections of the MLT data from the ocean heat fluxes and of mean sea framework assigns to link the terrestrial space and ground provide us opportunity level pressure compared to previous and space weather and climate to explore their reanalysis in WA models. reanalyses. applications. Current advances in the We overview the current status of data WAM developments and in their coupling analysis studies in the WAM/WDAS of
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 30 products by establishing collaborative existing global reanalyses, and whether Thus, the fidelity of reanalysis Section 4 – Evaluation links between reanalysis centres and or not significant differences exist stratospheric WV is sensitive to how and intercomparisons data users. amongst them. accurately the fundamental drivers of stratospheric WV such as tropical The emphasis is on diagnostics of We present results from the WV and O of reanalyses 3 tropopause layer temperatures, methane the upper troposphere, stratosphere, intercomparisons that were performed oxidation, and the stratospheric and lower mesosphere. In the talk, an as part of the SPARC (Stratosphere- overturning circulation are represented. Results from the SPARC overview of the S-RIP activity during troposphere Processes and their Role Because of these issues and the known Reanalysis Intercomparison 2013-2017 is made, and some scientific in Climate) Reanalysis Intercomparison deficiencies in the representation of Project (S-RIP) during 2013-2017 highlights are presented and discussed. Project (S-RIP). stratospheric transport in reanalyses, Author Masatomo Fujiwara Comparisons are made over a range we find much poorer agreement Affiliation Hokkaido University Assessment of upper of timescales between the different both amongst reanalyses and reanalyses, and between reanalyses between reanalyses and independent Co-authors tropospheric and stratospheric and observational datasets. In addition observations. For these reasons, G. L. Manney (NWRA and New Mexico water vapor and ozone in to the intercomparisons, we discuss the stratospheric WV from the current Tech, USA), L. J. Gray (Oxford Univ. and reanalyses as part of S-RIP treatment of WV and O in reanalyses generation of reanalyses should generally NCAS, UK), J. S. Wright (Tsinghua Univ., 3 to aid future research and guide the not be used in scientific studies. China), and the S-RIP team Author Sean M. Davis interpretation of differences between the Affiliation NOAA ESRL The climate research community uses reanalysis fields. Because total column global atmospheric reanalysis data sets Co-authors ozone (TCO) is assimilated in the newer Preliminary assessment of to understand a wide range of processes M.I. Hegglin (Univ. Reading), M. Fujiwara reanalyses, these reanalyses generally the ERA5 ozone reanalyses (Hokkaido Univ.), R. Dragani (ECMWF), and variability in the atmosphere, yet reproduce TCO well except when data Author Rossana D. Dragani different reanalyses may give very Y. Harada (JMA), C. Kobayashi (MRI/ coverage is lacking, such as during ECMWF different results for the same diagnostics. JMA), C. Long (NCEP/NOAA), G.L. polar night. Affiliation The Stratosphere–troposphere Manney (NWRA/New Mexico Tech.), Co-authors We find that the vertical distribution of Processes And their Role in Climate E. Nash (SSAI), G.L. Potter (NASA GSFC), H.H. Hersbach (ECMWF), ozone is relatively well represented in (SPARC) Reanalysis Intercomparison S. Tegtmeier (GEOMAR), T. Wang C.S. Soci (ECMWF) reanalyses, particularly given that for Project (S-RIP, https://s-rip.ees.hokudai. (NASA JPL), K. Wargan (NASA GMAO), most reanalyses there are only weak ECMWF is currently producing the ac.jp) is a coordinated activity to J.S. Wright (Tsinghua Univ.) constraints on the vertical profile of ERA5 reanalysis that will replace the compare reanalysis data sets using a Reanalysis datasets are widely used ozone from observations and that most widely-used ERA-Interim atmospheric variety of key diagnostics. to understand atmospheric processes have a simplistic representation of ozone reanalysis. Produced as part of the The objectives of this project are to and past variability, and are often used photochemical processes. In contrast EU-funded Copernicus Climate Change as “observations” for comparison identify differences among reanalyses to O3, stratospheric WV data are not Service, ERA5 will be open and freely and understand their underlying causes, with climate model output. Because currently assimilated, with humidity available to all. The ERA5 reanalysis to provide guidance on appropriate of the central role of water vapor (WV) observations typically used only in the is based on a significantly different usage of various reanalysis products in and ozone (O3) in climate change, it is troposphere below a specified vertical and, in general, much-improved data scientific studies, particularly those of important to understand how accurately level at or near the tropopause. assimilation system compared to its relevance to SPARC, and to contribute these species are represented in the predecessor, including in its ozone to future improvements in the reanalysis component.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 31 Section 4
The ERA5 ozone reanalyses benefit from multi-decadal timescales it is expected to year older. Such large disagreements Regional biases introduced by this largely reprocessed datasets, many decrease with rising levels of greenhouse of AoA values are found in the whole shortcoming are order 20Wm-2 and of which were generated with special gases in the atmosphere. Satellite stratosphere. strongest in the tropics. A second attention to climate and reanalyses observations of stratospheric tracers SF6 ambiguity arises from different reference The time evolution also differs applications, e.g. those retrieved as part of and HCl indicate that AoA did decrease states of water in the climate system: considerably depending on the reanalysis the ESA-funded Climate Change Initiative. in the Southern Hemisphere during the vapor at 0K in the atmosphere and considered, e.g. JRA-55 delivers AoA Compared to ERA-Interim, ozone-sensitive first decade of this century but also that liquid at 0°C in the ocean. Additionally, trends over 2002-2012 which are nearly radiances in the infrared (IR) from several it increased in the Northern Hemisphere. small inconsistencies in formulations of insignificant in the Northern Hemisphere IR sounders are assimilated in ERA5. the energetics of current weather and This dipole structure of AoA trends and display no detectable dipole structure climate models are highlighted. A more A variational bias correction model was has been confirmed by transport between the two hemispheres. Hence the consistent energy budget framework implemented for ozone observations simulations driven by the ERA-Interim multi-annual to multi-decadal evolution is presented, which takes into account to improve the data exploitation and reanalysis but not by in situ observations of AoA depicted by modern reanalyses is surface mass and associated enthalpy remove potential inter-instrumental biases in the stratospheric northern mid- not yet sufficiently clear or consistent to fluxes and is independent of reference that normally affect different datasets latitudes, which have not yet delivered be used as a diagnostic for the evaluation temperature in the steady state. of the same quantity causing a loss of any significant trend over a forty-year of chemistry-climate models. performance when jointly assimilated. time period. Hence further research Using atmospheric data from ECMWF’s is required about the magnitude, ERA-Interim and JMA’s JRA-55 In this contribution, we will first introduce distribution and detectability of AoA Towards consistent diagnostics reanalyses, several resulting implications the ERA5 ozone system, and discuss trends. As part of the SPARC Reanalysis of the coupled atmosphere and are illustrated. First, it is shown that the differences from its predecessors, Intercomparison Project (S-RIP), we have ocean energy budgets material surface energy fluxes (including and then present some results from a developed a pre-processor to feed a snowfall) globally have a net cooling effect preliminary assessment of the quality of Author Michael Mayer Eulerian transport model with any of the on the Earth’s surface (-1.3Wm-2), with the ERA5 ozone reanalyses. available global (re-)analysis datasets. Affiliation University of Vienna much larger regional values. This implies Co-authors that the non-material (radiative plus This allowed us to compute the age of L. Haimberger (University of Vienna), turbulent) surface energy flux (FS) must Mean age of stratospheric air air in the stratosphere and its evolution J. Edwards (UK Met Office), P. Hyder be higher than previous estimates in order since 1985: large disagreements from 1985 to 2015, according to five (UK Met Office) to balance the material surface energy between five modern reanalyses modern reanalyses: ERA-Interim, JRA- flux and the observed ocean warming. 55, MERRA, MERRA-2 and CFSR/ The widely used diagnostic vertically Author Simon Chabrillat CFSv2. Our results compare favorably integrated total energy budget equations Second, the agreement between fields Affiliation BIRA-IASB with those published previously using of atmosphere and ocean are re- of FS inferred from satellite-measured Co-authors ERA-Interim. It turns out that the other examined and several inconsistencies are radiation and reanalysis-based Y. Christophe (BIRA-IASB), C. Vigouroux reanalyses deliver surprisingly different revealed. First, there is a dependence on divergence of atmospheric lateral energy (BIRA-IASB), Q. Errera (BIRA-IASB), and diverse results. For example at 20km reference temperature because enthalpy transports with independent surface flux E. Mahieu (U. Lg) height and for year 2000, JRA-55 delivers fluxes associated with precipitation and products is substantially improved when AoA up to one year younger than ERA-I evaporation (material surface energy using the here-presented instead of the Chemistry-climate model simulations have while MERRA delivers AoA up to one fluxes) are usually neglected. commonly used budget formulation. shown that the mean age of stratospheric air (AoA) is a good indicator of the strength of the residual circulation, and that at
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 32 Section 4
Third, results imply that previous better than the precipitation generated naturalized streamflow measurements to isolate the effect of soil moisture on studies seriously underestimated cross- by the atmospheric models within in the United States are, on balance, atmospheric conditionse estimate and equatorial atmospheric and oceanic the cycling MERRA-2 system and the highest for MERRA-2 and ERA-Interim/ compare soil moisture-temperature energy transports. Overall, the improved earlier MERRA reanalysis. Compared Land, somewhat lower for MERRA-Land, coupling strength using re-analysis data framework allows for unambiguous energy to 3-hourly TRMM observations, the and lower still for MERRA. (ERA-Interim/Land, MERRA-2) on the budget diagnostics based on reanalyses M2CORR diurnal cycle has better one hand and a dataset combination and will help to provide more reliable amplitude but less realistic phasing than that includes remote sensing data and benchmark values for validation purposes MERRA-2 model-generated precipitation. Quantifying spatio-temporal gridded station observations on the variations of soil moisture other hand. For the relation between soil Because correcting the precipitation control on surface energy moisture and evaporative fraction three within the coupled atmosphere-land Land surface precipitation key parameters are estimated: 1) the modeling system allows the MERRA-2 balance and near-surface and hydrology in MERRA-2 frequency of the occurrence of different near-surface air temperature and air temperature soil moisture regimes, 2) the sensitivity Author Rolf H. Reichle humidity to respond to the improved Author Clemens Schwingshackl of evaporative fraction to soil moisture Affiliation NASA/GSFC precipitation forcing, MERRA-2 Institute for Atmospheric variations in the transitional soil moisture provides more self-consistent surface Affiliation Co-authors and Climate Science, regime, and 3) the critical soil moisture meteorological data than were available R. D. Koster (NASA/GSFC), C. S. Draper ETH Zürich value which separates water- and energy- (NASA/GSFC and USRA/GESTAR), from the earlier, offline MERRA-Land Co-authors limited evapotranspiration regimes. Q. Liu (NASA/GSFC and SSAI), M. Girotto reanalysis. Overall, MERRA-2 land M. Hirschi (Institute for Atmospheric (NASA/GSFC & USRA/GESTAR), hydrology estimates are better than those All used datasets agree well in the overall and Climate Science, ETH Zurich, S. P. P. Mahanama (NASA/GSFC and of MERRA-Land and MERRA. geographical distribution of the single Switzerland), S.I. Seneviratne (Institute soil moisture regimes, but there are SSAI), G. J. M. De Lannoy (KU Leuven), A comparison against GRACE satellite for Atmospheric and Climate Science, differences in the classification in some and G. S. Partyka (NASA/GSFC & SSAI) observations of terrestrial water storage ETH Zurich, Switzerland) distinct regions. Regarding the sensitivity The Modern-Era Retrospective Analysis demonstrates clear improvements in Soil moisture plays a crucial role for the of evaporative fraction to soil moisture for Research and Applications, version MERRA-2 over MERRA in South America energy partitioning at the Earth’s surface. variations, all datasets reveal similar 2 (MERRA-2), provides global, 1-hourly and Africa but also reflects known errors Changing shares of latent and sensible patterns, but the absolute values vary estimates of land surface conditions in the observations used to correct the heat fluxes, caused by soil moisture between the different datasets. for 1980-present at ~50-km resolution. MERRA-2 precipitation. The MERRA-2 variations, can affect both near-surface air Outside of the high latitudes, MERRA-2 and MERRA-Land surface and root zone Eventually, the analysis allows to estimate temperature and precipitation. Here, we use uses observations-based precipitation soil moisture skill vs. in situ measurements the effect that soil moisture variations a simple framework for the dependence of data products to correct the precipitation is slightly higher than that of ERA-Interim/ have on near-surface air temperature. evaporative fraction (the ratio of latent heat falling on the land surface. Land and higher than that of MERRA While the different datasets agree well (significantly for surface soil moisture). flux over net radiation) on soil moisture to on the magnitude (typical soil moisture This paper describes the precipitation analyze spatial and temporal variations of variations can impact air temperature Snow amounts from MERRA-2 have correction method and evaluates the land-atmosphere coupling and its effect by several kelvin), there are apparent lower bias and correlate better against MERRA-2 land surface precipitation on near-surface air temperature. differences in the patterns between the and hydrology. Compared to monthly reference data than do those of MERRA- This framework allows to separate re-analyses and the combined dataset, GPCPv2.2 observations, the corrected Land and MERRA, with MERRA-2 skill water-limited from energy-limited especially in Africa and South America. MERRA-2 precipitation (M2CORR) is roughly matching that of ERA-Interim/ Land. Seasonal anomaly R values against evapotranspiration regimes and thus
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 33 Section 4
The results emphasize the role of soil ensemble CERA-20C (ECMWF, 2017) are For more detailed investigations daily moisture for atmosphere and climate and yielded from the projects ERA-Clim and precipitation is clustered into events Improved SST-precipitation highlight that a proper integration of these ERA-Clim2. based on days with more than 1 mm relationships in the CERA-20C processes in weather and climate models precipitation. Here, only grid-points with The multi-decadal reanalyses cover more coupled climate reanalysis is crucial. Important efforts have been more than 250 events were considered to than one century from 1900 to 2010 made in the recent years to create datasets have statistical sufficient quantity, which Author Xiangbo Feng and have a spatial resolution of about for a more thorough investigation of land- excludes very dry area like Sahara or Affiliation Department of 125 km. The reanalyzes are produced atmosphere coupling. Yet, our results show very wet areas like Indonesia. meteorology, University by the ECMWF’s IFS forecast model, that precise conclusions about the soil of Reading but for CERA-20C the IFS model for the Not surprisingly, the regions with the moisture-temperature coupling strength atmosphere is coupled with the NEMO strongest differences are also those with Co-authors are still uncertain due to the limited model for the ocean and to the LIM2 data scarcity, mountain regions with Keith Haines, Chunlei Liu (Department availability of adequate observations. model for sea ice. their Luv and Lee effects or monsoon of Meteorology, University of Reading, areas. They all show a strong systematic Reading, UK The in-situ products of the Global difference and breaks within the time Assessment of precipitation Precipitation Climatology Center (GPCC) ECMWF has recently produced the 20th series. Differences based on ETCCDI in the CERA-20C and ERA-20C were used as a reference: The Full century ocean-atmosphere coupled diagnoses were detected particularly reanalyses by means of Data Monthly (FDM) (Schneider et al., reanalysis CERA-20C, following on in regions with large precipitation totals 2014) containing global land surface from the similar uncoupled atmosphere precipitation gauge observations especially in Africa in the ITCZ area and precipitation from 1901 to 2013 with reanalysis ERA-20C. The local SST- in Indonesia. The overall comparison Author Elke Rustemeier monthly resolution, and the Full Data precipitation relationships are an reveals geo-spatially heterogeneous Affiliation Deutscher Wetterdienst Daily (FDD) (Schamm et al., 2014) from indicator of air-sea interactions at sub- results with areas of similar precipitation 1988 to 2013 with daily resolution. seasonal timescales in CERA-20C and Co-authors characteristics, but there are also still For both data sets, the respective ERA-20C, and these are compared with M. Ziese, A. Meyer-Christoffer, areas that present a challenge. U. Schneider, P. Finger, A. Becker overlapping period was chosen for the observations using monthly data over (Deutscher Wetterdienst, evaluation, 23 years (1988-2010) for FDD Additionally, areas with matching 1979-2010. Hydrometeorology, Offenbach and 110 years (1901-2010) for FDM with precipitation totals do not necessarily In convective regions, the negative am Main, Germany) 1° spatial resolution. show matching extreme value indices, or SST-precipitation correlations in even the indices show inconsistent results Through annual and seasonal totals, a observations are well captured in CERA- Precipitation is a difficult parameter for depending on the region. reanalyses models, but it also has a good global overview of the consistency 20C, while these are not well reproduced strong impact on our daily life. But since and the quality of the modeled in ERA-20C, which is more likely to precipitation has not been assimilated precipitation can be obtained by show positive correlations. It appears into the reanalyses, it is possible to means of correlation and contingency that in the coupled reanalysis ocean assess the predicted precipitation table scores. Climate change indices surface can cool down with less surface with independent observation. Both (ETCCDI) for precipitation are calculated solar radiation associated with more reanalysis, ERA-20C deterministic (Poli to determine extreme values and their precipitating clouds. et al., 2015) and the 10-member temporal change (Peterson et al., 2001, However, in the uncoupled data, the Appendix A). prescribed SST does not respond to atmosphere feedbacks. Consequently,
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 34 Section 4 in the coupled reanalysis the mean This presentation summarizes the Interannual variability of the distribution precipitation is better estimated over evaluation of Arctic sea ice cover of thin/thick ice differs among the Uncertainty in Reanalysis most of the tropical and subtropical in global ocean-sea ice reanalyses reanalyses, which questions the over Europe oceans, although it is worse over South conducted as part of the Clivar-GSOP/ suitability of current sea ice reanalyses America. We discuss the physical GODAE OceanView Ocean Reanalyses to initialize seasonal forecasts of the Author Peter Jermey mechanisms controlling the SST- Intercomparison Project (ORA-IP). Arctic sea ice. An evaluation of the sea Affiliation Met Office precipitation relationship at sub-seasonal Analyses have been conducted on a set ice velocity fields reveals that ice drifts Co-authors timescales and how this can also impact of 14 global reanalyses, among which too fast in most systems, although the Richard Renshaw, Jemma Davie the longer-term variations and trends in 9 assimilated sea ice concentration interannual variability of average velocity (Met Office) precipitation in the coupled product. data. Differences between the various and Fram Strait ice export is reasonably reanalyses are explored in terms of well reproduced in all systems. The Uncertainties in Ensembles of the effects of data assimilation, model Regional ReAnalyses (UERRA) project The simulated sea ice velocity seems An intercomparison of the Arctic physics and atmospheric forcing on the has produced regional reanalyses of the directly impacted by the choice of sea ice cover in global ocean- simulated Arctic sea ice concentration, atmosphere over Europe. The principal dynamical model parameters, which is sea ice reanalyses from the thickness and velocity. contributions of the Met Office (UK) to not obvious for sea ice thickness. As project ORA-IP the project are a 12km deterministic The comparison reveals an overall an ensemble, the ORA-IP reanalyses reanalysis and a 20 member 36km Author Matthieu Chevallier agreement in the reconstructed capture trends in Arctic sea ice area ensemble reanalysis, both covering the concentration fields, mainly because and extent relatively well. However, Affiliation CNRM, Météo France satellite era. The scale of atmospheric of the constraints imposed by direct the ensemble can not be used to get features that can be represented by Co-authors assimilation of ocean and/or sea a robust estimate of recent trends a gridded reanalysis is limited by the Greg Smith (MRD, Environment Canada, ice observations and prescribed or in the Arctic sea ice volume. Recent resolution of the model grid and its Dorval, Canada), Frédéric Dupont assimilated atmospheric forcing. developments within the Polar Ocean accuracy is dependent on observations, (MSC, Environment Canada, Dorval, Reanalyses Intercomparison Project A large spread in sea ice thickness is model and boundary conditions, which Canada), Jean-François Lemieux (CMC, (PORA-IP) will be mentioned, including found within the ensemble of reanalyses, all contain uncertainty. Environment Canada, Dorval, Canada), updates of the analysis on Arctic sea partially caused by the biases inherited Magdalena Balmaseda (ECMWF, ice with a more recent generation of Activities to measure uncertainty in from their sea ice model components. Reading, UK), Keith Haines (NCEO, ocean reanalyses, and insights on the reanalyses have often been limited by the Biases are also affected by the University of Reading, UK), Petteri Uotila representation of the Antarctic sea ice lack of available independent measures assimilation of sea ice concentration and (FMI, Finland), Hugues Goosse (Université cover in global ocean reanalyses. of the true state of the atmosphere, de Louvain-la-Neuve, Belgium), François the treatment of sea ice thickness in the however such capability is highly Massonnet (Université de Louvain-la- data assimilation process. The spatial desirable in order to inform a diverse set Neuve, Belgium), Gilles Garric (Mercator distribution of ice volume varies widely of users on the suitability of the data. If Océan, France), Doroteaciro Iovino between products, with no reanalysis uncertainty is not transparent to users, (CMCC, Italy), Frank Kauker (AWI, standing out as clearly superior as they may assume the reanalysis data is Germany), the ORA-IP and PORA-IP compared to altimetry estimates. certain or that the uncertainty does not teams. The ice thickness from systems without vary. assimilation of sea ice concentration is not worse than that from systems constrained with sea ice observations.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 35 Section 4
By perturbing sources of uncertainty, the database. More than 800 on site only 20th century reanalysis (20CR) to the UERRA ensemble reanalysis estimates measurement time series were employed Do reanalyses capture long-term much higher-resolution full-input JRA55 the uncertainty in the ensemble mean. to obtain a complete understanding changes in extreme weather reanalysis of the 1959-2012 period, This capability will be evaluated to of the performance of Reanalysis and statistics? plus two large ensembles of model demonstrate how reanalysis uncertainty derived WRF downscaled output in the simulations of the period generated using varies with space, time and synoptic context of wind industry applications. Author Prashant D. the 20CR model with two different sets of condition. The impact of the changing Sardeshmukh SST and sea-ice boundary conditions. We intend with this presentation to observing system over forty years will Affiliation CIRES/University of provide a comprehensive metrics of The changes in extreme temperatures from also be demonstrated. Colorado and Physical different Reanalysis projects (ECMWF the first to the second half of the period Sciences Division/NOAA Era-Interim and ERA5, MERRA2, CFS/ agree well among the reanalyses, although 800+ site validation of Reanalysis CFSR and JRA55) and to map the Co-authors less well than the changes in mean & downscaled wind conditions climate quality for wind industry end- G.P. Compo, A. Wang, C. McColl temperatures. This is shown to be mostly (all CIRES, University of Colorado time series users. A large databank of over 800 due to disagreement in representing site with windmast measurements was and Physical Sciences Division/NOAA) changes in the temperature variance. The Author Gil Lizcano employed for the validation of modeled The ability of reanalyses to represent model simulations capture the essence of Affiliation Vortex wind time series. The sites represent a long-term changes in the climate system is the extreme changes in most regions, but large spectrum of flow complexity across differ more from the reanalyses than the Co-authors often questioned, despite their advantages different locations for most of the wind reanalyses differ among themselves. O. Lacave, Vortex, P. Casso, Vortex, of filtering out observational error and local industry target markets. A. Bosch, Vortext, A. Monternes, Vortex noise at the observation locations and of This adds credence to both the extreme In particular, time correlation, consistency generating physically consistent estimates changes inferred from the reanalyses Model data are employed at different and bias and RMSE are provided for of other variables at other locations. and the beneficial impact of even just stages of the windfarm development: different categories and locations. the surface pressure observations in country engagement, resource This is because these advantages are Comparison between raw Reanalysis constraining those reanalyses. Similar screening, site identification, preliminary compromised by the sparseness and data and 3km and 100m downscaled conclusions drawn from comparing feasibility studies and due diligence errors of the observations in the earlier products will be presented to assess the changes in extreme daily precipitation process. Over the last 5 to 10 years, parts of the record, which cause the added value of the augmented resolution. statistics over the shorter 1979-2012 Reanalysis and downscaled products reanalyses to be more heavily influenced period will also be discussed. have been adopted by the wind industry by errors in the assimilating model’s as a feasible solution to complement guess fields, specified boundary on-site measurements and to fill the lack conditions and radiative forcings. of information demanded by a global The problem is relatively more serious for maked with project developments in assessing changes in extreme weather places as differents as North Chile, statistics. We have addressed this issue Anatolia complex mountains, North Sea by examining changes in the probabilities or Kenyan valleys. of extreme lower tropospheric 5-day This work provides an global wide insight averaged temperature anomalies in five on the quality of wind conditions virtual global reanalyses ranging in complexity time series based on latest Reanalysis from the low-resolution surface-input
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 36 Section 4
Sensitivity to Observations (EFSO) which The AFES-LETKF data can quantify how much each observation assimilation system for an has improved or degraded the forecast experimental atmospheric without a data denial experiment has global ensemble reanalysis been recently implemented into ALEDAS. The preliminary results from EFSO Author Akira Yamazaki will be compared against OSE. Affiliation Japan Agency for Marine- Earth Science and Technology (JAMSTEC) Co-authors Takeshi Enomoto (Disaster Prevention Research Institute, Kyoto University), Takemasa Miyoshi (RIKEN Advanced Institute for Computational Science), Nobumasa Komori (Application Laboratory, JAMSTEC) A global atmospheric data assimilation system called ALEDAS comprised of AFES (Atmospheric GCM for the Earth Simulator) and LETKF (Local Ensemble Transform Kalman Filter) has been developed and is used to generate the experimental atmospheric global ensemble reanalysis (ALERA) dataset available from January 2008 to January 2013, which has been prolonged toward near real time analysis. With ALERA and ALEDAS, several OSE studies have been conducted to assess impacts of radiosonde observations obtained during some observational campaigns, especially on the Arctic and subtropical oceans. Recently we have also performed some weather predictability studies by using ALERA and/or the OSE reanalyses as initial values for AFES. In addition, a diagnostic technique called Ensemble Forecast
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 37 its temporal changes from a combined Section 5 – use of ocean observing systems and Reanalyses’ use in operational Stratospheric intrusion- Applications of numerical model techniques. weather forecasting influenced ozone air quality reanalyses Moreover, ocean reanalysis systems Author Roberto Buizza exceedences investigated in the NASA MERRA-2 Reanalysis deliver us a unique insight into the role Affiliation ECMWF of the oceans as energetic buffer and Insights into the role of the Author Katherine Emma Knowland regulator through its capacity to absorb In the past two decades we have Affiliation Universities Space oceans in the Earth energy and to redistribute large amounts of heat. seen an increased use of reanalysis Research Association budget from ocean reanalysis In addition, consistency checks through in operational weather forecasting. (USRA) GESTAR & physical budget constraints with the Reanalyses provide initial conditions for Author Karina von Schuckmann NASA GMAO combined use of climate observations reforecasts, i.e. forecasts re-run using Affiliation Mercator Océan (in situ, remote sensing) and tools operational systems for past cases, both Co-authors (reanalysis, climate models) have a large L.E. Ott (NASA/GMAO, GSFC, Greenbelt, Improving the accuracy of estimates of to improve operational forecast products potential to deliver a robust uncertainty MD), B.N. Duncan (Laboratory for Earth’s climate state and variability is and to provide users with a more assessment, to shed new light on Atmospheric Chemistry and Physics, GSFC, critical for advancing our understanding solid performance assessment of the unresolved climate science issues and Greenbelt, MD), Krzysztof Wargan (Science and prediction of the evolution of Earth’s accuracy and reliability of the operational to strengthen the exchange between Systems & Applications, Inc. (SSAI); NASA/ climate. The energy budget of the forecasts. Examples of operational multi-disciplinary experts all concerned GMAO, GSFC, Greenbelt, MD) Earth is a key determinant for the state products generated using reforecasts are with the energy flow through the climate and evolution of climate on our planet. the ECMWF Extreme Forecast Indices for Ozone near the surface is harmful system. Perturbations of this budget from internal 2-meter temperature and precipitation. to human health and is a result of or external climate variations create a This talk will give an overview on the They are defined by comparing the photochemical reactions with both man- radiative flux imbalance at the top of the development of ocean climate indicators probability distribution function of forecast made and natural precursor pollutant atmosphere. such as EEI from ocean reanalyses, their states computed using the most recent sources. Therefore, in order to reduce use for physical budget constraints, near surface ozone concentrations, This Earth Energy Imbalance (EEI) is ECMWF ensemble of forecasts, and and the evaluation on the redistribution communities must reduce anthropogenic shaped by several climate forcings, some the model climatological distribution of ocean heat. Specific examples will pollution sources. of which occur naturally and some that function computed using an ensemble of be introduced and main outcomes and are anthropogenic in origin. There is reforecasts initialized using reanalyses for However, the injection of stratospheric challenges are discussed. a current positive EEI, which is mostly the past 20 years. ozone into the troposphere, known caused by human activity, and which is Examples of performance estimation as a stratospheric intrusion, can also driving global warming. The EEI can best based on reforecasts initialized from lead to concentrations of ground-level be estimated from changes in ocean reanalyses are the reliability diagrams of ozone exceeding air quality standards. heat content, complemented by radiation the ECMWF seasonal ensemble forecasts Stratospheric intrusions are dynamical measurements from space. Ocean of sea-surface temperature anomalies in atmospheric features, however, these reanalysis systems are critical for the a set of tropical regions, e.g. covering the intrusions have been misrepresented in evaluation of the EEI as they deliver a 3-D El Niño areas in the tropical Pacific Ocean. models and reanalyses until recently, view on the interior of our oceans and During this talk, I will review the use of as the features of a stratospheric reanalyses in the ECMWF operational intrusion are best identified in horizontal production process. resolutions of 50 km or smaller.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 38 Section 5
Modern Era Retrospective Analysis for rainfall over the South Korea-Japan Classification of Meteorological Research and Applications, version 2 Role of Southern Annular Mode peninsula (June through August: JJA, Influences Surrounding Extreme (MERRA-2), have become a pivotal tool on Asian Monsoon: Mechanisms Amita et.al 2017). to study the meteorology surrounding Precipitation Events in the through NCEP-NCAR Reanalysis Delayed response over South as well extreme precipitation events. Using days United States using the as over East Asia is relayed through the classified as an extreme precipitation Author Amita Prabhu central Pacific sea surface temperatures. MERRA-2 Reanalysis events based on a combination of Affiliation Indian Institute of Tropical A negative (positive) phase of SAM observational gauge and radar data, two Meteorology Author Allison Collow generates a wave-train which propagates techniques for the classification of these Affiliation Universities Space Co-authors from the sub-polar latitudes towards events are used to gather additional Research Association R. H. Kripalani (Indian Institute of Tropical the equatorial latitudes associated information that can be used to determine (USRA) & NASA GSFC Meteorology), G. Pandithurai (Indian with warming (cooling) over the central how events have changed over time using Institute of Tropical Meteorology) equatorial Pacific region. Co-authors atmospheric data from MERRA-2. M. Bosilovich (NASA GSFC), The annular modes are the most This warming (cooling) induces an The first is self organizing maps, which and P. Ullrich (UC Davis) important hemispheric scale patterns ascending (descending) motion over is an artificial neural network that uses of climate variability in the northern and the central Pacific with descending Extreme precipitation events can have a unsupervised learning to cluster like the southern hemisphere. The Southern (ascending) motion over the (i) Indian large impact on society through flooding patterns and the second is an automated Annular Mode (SAM) is characterized by subcontinent through the zonal Walker that can result in property destruction, detection technique that searches for a see-saw phenomenon between the sea circulation influencing the ISMR; crop losses, economic losses, the spread characteristics in the atmosphere that level high pressure belt normally across (ii) Korea-Japan sector through the of water-borne diseases, and fatalities. define a meteorological phenomena. For ~400S and a low pressure belt across meridional Hadley circulation influencing Observations indicate there has been example, the automated detection for ~700S. SAM is also referred as a High- the peak July-August monsoon over a statistically significant increase in tropical cycles searches for a defined latitude Mode or the Antarctic Oscillation. Korea-Japan. These findings have extreme precipitation events over the area of suppressed sea level pressure, SAM index is defined as MSLP 400S – potential implications on the seasonal past 15 years in the Northeastern United alongside thickness anomalies aloft, MSLP 700S. forecasts of both the South and East States and other localized regions of indicating the presence of a warm core. the country have become crippled with Based on the National Centers for Asian summer monsoons. record flooding events, for example, the These techniques are employed Environmental Prediction and National flooding that occurred in the Southeast for extreme precipitation events in Center for Atmospheric Research United States associated with Hurricane preselected regions that were chosen (NCEP/NCAR) Reanalysis data spanning Matthew in October 2016. based an analysis of the climatology 31 years for the period 1983-2013, of precipitation. Extreme precipitation events in the results reveal that while the February- United States can be caused by various March SAM has a significant positive meteorological influences such as relation with the subsequent Indian extratropical cyclones, tropical cyclones, summer monsoon rainfall (June through mesoscale convective complexes, September: ISMR; Amita et.al. 2016), the general air mass thunderstorms, upslope May-June SAM has a significant positive flow, fronts, and the North American relation with the summer monsoon Monsoon. Reanalyses, such as the
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 39 Section 5
percentiles. Strong seasonal and spatial For example, time series of temperature presentation, a summary of our recent Intercomparison of the near- variability have been identified with an and precipitation are available at experience of these user requirements surface wind speed trends increase of the wind speed over the sufficiently high spatial density since will be given. ocean and a decline over land, although 1881 and can be used to derive monthly in three reanalyses The Work Package on Evaluation in disagreement between the reanalyses maps of these parameters which are the European FP7-Project UERRA Author Verónica Torralba has been identified, particularly for the used to provide monthly updates on (“Uncertainties in Ensembles of Regional Affiliation Barcelona JRA-55 reanalysis which overestimates the state of climate in Germany to the ReAnalyses”) is focusing on the evaluation Supercomputing the trends over land. The causes of public (see e.g. http://www.deutscher- of user-relevant parameters and provides Center (BSC) these wind speed trends are discussed klimaatlas.de). However, in recent years results for selected requirements from the in terms of the wind speed at 850 hPa, new requirements for improved climate Co-authors renewable energy sector. F. J. Doblas-Reyes (Barcelona because although changes in land use, monitoring products came up, which Supercomputing Center (BSC), aerosols and the recent modifications cannot be fulfilled with such a traditional Institució Catalana de Recerca i Estudis of the large-scale circulation have been approach. identified to play a role over wind speed Avançats (ICREA)), N. Gonzalez- One important example are wind trends, it is still not fully understood how Reviriego (Barcelona Supercomputing conditions at different height levels, over these factors could affect wind speed Center (BSC)), L. Lledó (Barcelona land but also over the North and the trends at global scale. Supercomputing Center (BSC)), Baltic Sea. At these locations and heights, R. Marcos (Barcelona Supercomputing no long series with direct observations Center (BSC)), N. Cortesi (Barcelona On requirements for the are available. In addition to that wind Supercomputing Center (BSC)) and application of reanalyses in the measurements from conventional stations A. Soret (Barcelona Supercomputing context of climate monitoring and might be affected by inhomogeneities. Center (BSC) Improved climatologies are not only energy applications in Germany Wind energy users have recently requested by the commercial sectors, incorporated reanalyses products for the Author Frank Kaspar but are also needed for assessments of different government agencies, e.g. evaluation of the long-term wind speed Affiliation Deutscher Wetterdienst variability, particularly in those regions for continuously assessing the progress Co-authors in the transition of the energy sector or where there are not long observational A. K. Kaiser-Weiss (Deutscher records available. This study explores the providing basic information for longer- Wetterdienst), M. Borsche term decisions in the energy sector. wind speed long-term trends at global (Deutscher Wetterdienst) scale in the last decades (1980-2015) Regional reanalysis has the potential using three reanalyses: ERA-Interim, Germany’s meteorological service to provide the required products, but a Japanese 55-year Reanalysis (JRA- (Deutscher Wetterdienst) is responsible to quality assessment of these products is 55) and Modern Era Retrospective- provide regular statements on climate and a prerequisite. The applications therefore Analysis for Research and Applications climate change in Germany. Traditionally, have implications on the requirements (MERRA-2). these statements are based on the long for uncertainty estimates and timeliness time series of meteorological observations of the reanalysis products. In the 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
and climate applications, and CTRIP is In this study, we first assess the low- On the use of the 50-year high- the river routing model used for climate Development of long-term frequency variations of precipitation and resolution UERRA re-analysis applications at Météo-France. hydro-meteorological temperature over France in the long- term atmospheric reanalyses. Then, for a hydro-meteorological Such a system provides not only reconstructions over France a new statistical approach based on application over Europe ECVs, such as soil moisture, snow based on large scale the results of a statistical downscaling depth, etc., but also computes the Author Patrick Le Moigne atmospheric reanalyses to study method applied to the reanalyses various components of the water the multi-decadal variability and constrained by available long- Affiliation Météo-France cycle: precipitation, surface runoff, soil of French river flows term homogenized precipitation and Co-authors infiltration and water storage, as well as temperature observations over France is C. Szczypta (Météo-France), A. Verrelle the time evolution of rivers discharge Author Rémy Bonnet presented. (Météo-France), E. Bazile (Météo-France), and aquifers height. A description of the Affiliation CECI-CERFACS R. Abida (Météo-France) MESCAN-SURFEX-CTRIP system will The reconstructed meteorological forcing Co-authors be done first. A detailed analysis of the and in particular the low-frequency The UERRA project is a 4-year project J. Boé (CECI-CERFACS), G.Dayon water cycle components climatology over variations are evaluated. The river (2014-2017) financed by the European (CECI-CERFACS) the 50-year period over Europe will be flows obtained with an hydrological Union under its 7th Framework done and comparisons with independent Recent studies based on the few model forced by the reconstructed Programme SPACE. One of its main observations of river discharges and available long-term observations show meteorological forcing are also compared objectives was to build a high resolution snow depths will be discussed. a large multidecadal variability in to the few available long-term observed (5.5km) 50-year reanalysis of surface French river flows. Understanding the series. The added value of constraining essential climate variables (ECV) over Uncertainties will also be discussed mechanisms behind this variability is a the results of statistical downscaling Europe, together with uncertainty based on simulations of a MESCAN- challenging issue, given the limitation of with homogenized observations is then estimates. The atmospheric UERRA SURFEX-CTRIP 8-member ensemble observed data-sets. The recent release discussed. The interest of our approach reanalysis relies on the HARMONIE covering the 2006-2010 period. Additional of two extended large-scale atmospheric to study the multidecadal variations in system and the ALADIN model at 11km information about the UERRA project can reanalyses (NOAA 20CR and ECMWF different variables of the continental horizontal resolution. be found at http://www.uerra.eu ERA20C) has opened great opportunities hydrological cycle over France is finally A downscaling at 5.5km is performed to The research leading to these results in that context. highlighted. derive wind and the downwards radiative has received funding from the European They can be downscaled, here with a fluxes, and to provide background fields Union, Seventh Framework Programme statistical downscaling method already for the MESCAN surface analysis of (FP7-SPACE-2013-1) under grant used in a climate change study, to 2m temperature and relative humidity agreement no 607193. and 24h accumulated precipitation. obtain the long-term high resolution These mesoscale fields are then used meteorological forcing needed for to drive hydro-meteorological off-line hydrological modelling. A limitation of simulations based on the coupled this approach is that the reconstructions SURFEX-CTRIP system, where SURFEX strongly depend on the quality of the is the land surface model developed reanalyses and some studies highlighted and used at Météo-France for NWP potential unrealistic long-term trends or artificial temporal variations in long-term reanalyses.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 41 Section 5
as predictors: daily precipitation and The circulation and hydrological From data mining to information its rolling sum, snow depth and its Mediterranean Sea circulation stratification are compared with the extraction: using ERA-Interim rolling sum, the first three modes of in high-resolution hindcast results of two different ocean reanalyses: reanalysis to model hydro-power geopotential height at European level. simulations and reanalyses MEDRYS and MFS, the latter being production in Europe We have used three distinct values for the ocean reanalysis performed for the the “width” of the rolling sum: five days, Author Gianmaria Sannino Mediterranean Sea within the framework Author Matteo De Felice 30 days and the value which maximise Affiliation ENEA of the Copernicus Marine Environment Affiliation ENEA the correlation with the generation data. Co-authors Monitoring Service (CMEMS). In particular MEDRYS have been performed Co-authors Four different models have been used A. Bargagli (ENEA), A. Carillo (ENEA), with the same configuration of the L. Dubus (EDF), A. Troccoli to model the daily generation of hydro- A. Dell’Aquila (ENEA), R. Iacono (ENEA), NemoMed model and use the same (University of East Anglia) power: linear-regression model, a E. Napolitano (ENEA), G.Pisacane (ENEA), forcing of the hindcast simulations. regression tree, an ensemble of model M.V. Struglia (ENEA), J.Beuvier (Mercator The installed capacity of renewable The availability of long time-series of trees and Random Forests. Using a Océan) energy sources (RES) is steadily Essential Climate Variables from ccean cross-validation procedure, all the increasing in European countries. For an Recent atmospheric reanalysis products, reanalyses is important for the validation combinations of models, countries efficient integration and management is such as ERA40 and ERA-Interim, and of the hindcast run of climate models, and generation type have been tested, important to be able to explicate the link their regional dynamical downscalings, which is mandatory in view of the use summarising the results using ranked between the meteorological variables prompted the scientific community of climate models for future scenario correlation. The modelling performance and the generation of electricity. To this to perform hindcast simulations of projections. for run-of-river is higher than the other end, several approaches can be used, the Mediterranean Sea, giving us the two categories: correlation is above NASA’s Modern-Era Retrospective including data-driven methods (statistical opportunity to evaluate the response of 0.9 for France, Germany, Romania and Analysis for Research and Applications models, machine-learning). ocean models to a realistic interannual Norway. air-sea fluxes atmospheric forcing. Version-2 (MERRA-2) reanalysis is a To successfully build a data-driven model publicly-available high-resolution dataset More surprisingly, the correlation is above On the other hand, ocean reanalysis it is fundamental the availability of high- (~50 km), with assimilated satellite 0.7 also for water reservoir generation for products represent an interesting quality data sets of observed data, i.e. retrievals of ozone, that characterizes countries like France, Germany, Portugal, reference dataset for the evaluation of generated electricity and meteorologica stratospheric and upper-tropospheric Norway, Spain and Sweden. We can these hindcast simulations. predictors for hydro-power modelling. ozone on the same spatiotemporal conclude that meteorological predictors, Hydro-power generation data has The objective of this work is to present resolution as the meteorology. We find such as those from the ERA-Interim been obtained from the ENTSO-E a comparison of two recent hindcast stratospheric intrusions which impact reanalysis, used as input to a purely Transparency Portal, divided in three simulations of the Mediterranean Sea surface air quality are well represented in statistical approach as that proposed categories (run-of-river, water reservoir Circulation, performed at 1/12° horizontal the MERRA-2 reanalysis. in this work, are effective at modelling, and pumped storage) and available for resolution with different ocean models and potentially predicting, hydro-power This is demonstrated through a case all the ENTSO-E countries since January (MITgcm and NemoMed). The simulations generation at country scale. study analysis of stratospheric intrusion 2015. share the same atmospheric forcing obtained by a downscaling of the ERA- events which were identified by the Meteorological data has been obtained Interim atmospheric reanalysis performed United States Environmental Protection from ECMWF ERA-Interim reanalysis. by the Regional Climate Model ALADIN- Agency (EPA) to contribute to elevated The following variables (averaged at Climate (ALDERA). ground-level ozone in spring 2012 in country-level) have been considered Colorado. The stratospheric intrusions
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 42 Section 5 are identified in MERRA-2 by the folding They can largely affect the estimate Further to assessing the eddy statistics simple dynamical downscaling of ERA of the dynamical tropopause under the of lateral turbulent fluxes of heat and from three different datasets, a global 3D 5 reanalysis data is applied through a jet stream and subsequent isentropic tracers together with vertical exchange eddy detection system is implemented cascade of regional atmospheric/wave descent of dry, ozone-rich stratospheric processes, typically occurring mostly in order to bypass the need of regional- models. A long-term goal of this study is air towards the surface near the location at wavelengths less than 100km. In this dependent definition of thresholds. It to identify the long-term trends in the last of the observed ozone air quality work, we focus on the role of assimilative thus provides full three dimensional eddy 30-35 years in order to better understand exceedences. schemes in enhancing the three- structures segmenting vertical profiles the effects linked to the impact of climate dimensional variability by comparing the from local rotational velocities. This change along the coast. The MERRA-2 reanalysis can support 3D eddy content and energetics among criterion is crucial for discerning real air quality agencies for more rapid The methodology applied is based on:- a three different datasets: a global ocean eddies from transient surface noise. Our identification of the impact of stratospheric high resolution atmospheric model (WRF- reanalysis (C-GLORS), a free global analysis shows that the latter impacts for air on surface ozone and demonstrates ARW), run at a horizontal resolution of ocean simulation (NEMO system) and an about the 10% of eddy population. that future operational analyses may aid about 3 km;- a finite element wave model observation-based dataset (ARMOR3D) in forecasting such events. (WW3), able to compute high-resolution used as an independent benchmark. Downscaling ERA-5 reanalysis waves along the coast, at a resolution Datasets are at 1/4 horizontal resolution up to 300-400 meters. Our target area A three-dimensional data for coastal climate and cover a 10-year period. While the applications and evaluation of is the North-Western Mediterranean, characterisation of eddy free simulation fairly reproduces eddies characterized by a marked variability in activities in a global ocean emerging from western boundary uncertainty of coastal data wind/wave regimes. currents and deep baroclinic instabilities, eddy-permitting reanalysis Author Carlo Brandini The evaluation period is 3 months it underestimates shallower vortexes. The Affiliation CNR Ibimet – Consorzio and the quality assessment has been Author Andrea Cipollone ocean Reanalysis recovers most of the LaMMA performed by using regional observed Affiliation CMCC missing turbulence that is not generated Co-authors data (coastal buoys and anemometers). Co-authors by the model itself and consistently Valerio Capecchi (CNR-Ibimet & Results show that regional downscaled S. Masina (CMCC, INGV), A. Storto projects surface variability through the Consorzio LaMMA), Francesco Pasi data provide lower errors in the mean (CMCC), D. Iovino (CMCC) full water column. (CNR-Ibimet & Consorzio LaMMA), wave parameters and wind regimes Ocean Reanalyses, at eddy-permitting Eddies are responsible for more than Stefano Taddei (Consorzio LaMMA), with respect to global data and some resolution, have nowadays reached a 60% of total EKE in regions where deep Alberto Ortolani (CNR-Ibimet & Consorzio significative improvements with respect satisfactory degree of accuracy that baroclinic instabilities occur and where LaMMA), Bernardo Gozzini (Consorzio to studies based on past reanalysis data. allows for first investigations about the eddy cores are shown to be located well- LaMMA). Moreover we present results concerning contribution of mesoscale variability below the ocean surface. Eddy thickness the use of the multiple members of the The management of coastal zones to the ocean dynamic and energetics. is also compared, ARMOR3D shows ERA5 data to improve the downscaled requires precise data concerning past Thanks to the new high-resolution much deeper eddies compared to the information. wind/wave regimes and future climate satellite products, data assimilation Reanalysis dataset where deep currents trends. Many studies have been based procedures can have a remarkable are consistently generated by the model on low resolution reanalysis data that impact on the ocean variability over a primitive equations thus embedding cannot allow a detailed description of the wide range of features that could not be baroclinic contribution from density variability induced by local conditions. well reproduced otherwise. gradient as well as several different processes. We present a feasibility study where a
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 43 Section 5
Global high-resolution simulation A roadmap to Earth surface capacity can benefit enormously next kilometre-scale simulations generation reanalyses products when combined with refinements in the Author Gianpaolo Balsamo treatment of physical processes to Affiliation ECMWF better account for regional and local Co-authors meteorological/climate/human-induced G. Arduini, A. Beljaars, S. Boussetta, changes. M. Choulga, E. Dutra, H. Herschbach, This presentation will cover current J. Munoz-Sabater, P. de Rosnay, efforts to characterise the Earth surface I. Sandu, N. Wedi (ECMWF) at kilometre-scale making use of recent The strive to produce increasingly more remote-sensing dataset in collaboration accurate forecasts has pushed horizontal with the Copernicus Services and it will resolutions of global Earth System illustrate some of the challenges with the Models (ESM) to break into single-digit internal consistency across datasets and kilometre-scale (e.g. 9 km for global with their use in long reanalysis. HRES forecasts at ECMWF with a vision to increase it further towards 2025), while many National Meteo-Hydrological Services already run at 1-2 km resolution on wide regional domains. At about 1km there is close to a billion grid points covering the Earth surface involving the use of High Performance Computing to be timely simulated. However, there are not only computing and software challenges involved, as accuracy requires to be able to characterise the surface ancillary conditions at those resolution (vegetation and soil, water-land-snow-ice fractions, and any meteorologically relevant properties) therefore involving satellite remote sensing observations and optimisation/inversion algorithms to 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 venerable NCEP/NCAR Reanalysis (R1). The accuracy was better near regions Section 1 – Status for the surface analysis (T2m, Rh2m, RR) This new reanalysis would be between with more observations such as the and plans of and to downscale the downward radiative these two extremes. Northern Hemisphere and closer to the fluxes and the wind at 5.5km required to surface. We did not find artifacts related The accuracy would have to be similar reanalysis drive SURFEX with the T2m, Rh2m and to the introduction of new satellites as or better then R1 without the gross precipitation analysis. CORe did not assimilate radiances from productions artifacts from the introduction of the satellites. However, we did encounter the various satellites. The reanalysis some other discontinuity issues that may would also have to span the 1950’s A 50 year surface analysis over A Conventional Enkf be related to stream boundaries and to to the present. Towards this goal, we Europe at 5.5km within the atmospheric REanalysis (CORe) the prescribed SST analyses. We will considered whether improvements in UERRA project show comparisons with other reanalyses. Author Wesley Ebisuzaki data assimilation and modeling would Author Eric Bazile Affiliation CPC/NWS/NOAA allow a modern system that assimilated Affiliation Météo-France/CNRS Co-authors conventional observations to have Aerosols in MERRA-2 and Plans similar or better accuracy than the old Co-authors A. Kumar (NOAA-CPC), J. Whitaker for Aerosols in Future GMAO R1 which assimilated satellite data using R. Abida, C. Szczypta, A. Verrelle, (NOAA-PSD), J. Woollen (NOAA-EMC), Reanalyses vertical temperature retrievals. We ran P. Le Moigne, C. Soci (1) (Météo-France H-C Lee (NOAA-CPC), L. Zhang an experimental reanalysis using an Author Arlindo M. da Silva CNRS) (1) ECMWF (NOAA-CPC) Ensemble Kalman Filter, atmospheric Affiliation NASA/Goddard Space The UERRA project is a 4-year project Atmospheric reanalyses can be data assimilation system (Jeff Whitaker, Flight Center (2014-2017) financed by the European optimized to produce the most accurate Climate Diagnostics and Predication Co-authors Union under its 7th Framework analyses by assimilating all observations Workshop, Orono, Maine, 2016). This V. Buchard (NASA/GSFC, USRA), Programme SPACE. One of its main including satellite observations. However, system used a T254 64 vertical-level C. Randles (Exxon Mobile), objectives is to provide a 50-year this type of reanalysis often shows semi-Lagrangian version of the GFS A. Darmenov (NASA/GSFC) reanalysis dataset of surface Essential discontinuities in various time series (Global Forecast System) model. Climate Variables (ECV) at 5.5km grid at with the introduction of new satellite MERRA-2 is NASA’s latest reanalysis The system assimilated conventional European scale, together with, as much systems. An atmospheric reanalysis can for the satellite era (1980-present) using observations, cloud-track winds and as possible, uncertainty estimates. also be optimized for a more consistent Version 5 of thr GEOS Earth System GPS-RO (COSMIC data). The last time series by limiting the observations model. This project focuses on historical The system used to provide the ECV two items use satellite data but are to a more temporally consistent set of analyses of the hydrological cycle on a and consistent other surface variables relatively insensitive to the biases in the observations. broad range of weather and climate time at 5.5km such as soil moisture at radiance measurements. We created an scales, and includes interactive aerosols several levels, surface evaporation, This was the approach used by the experimental reanalysis that spans 1950 for the entire period. As another step snow depth is based on a surface 20th Century Reanalysis (Campo et al to 2010. Using ERA-interim as a proxy for towards an integrated Earth System analysis (MESCAN) for 24h accumulated 2011) which only assimilated the surface truth, we found that the CORe reanalysis Analysis (IESA), MERRA-2 includes for precipitation (RR), 2m temperature pressure observations. The trade off was usually closer to ERA-interim than the first time aerosols in a reanalysis (T2m) and relative humidity (rh2m) and for the consistency was a less accurate R1 suggesting CORe met the accuracy for the satellite era, improves the on the surface platform called SURFEX. reanalysis because fewer observations requirement in the troposphere and lower representation of stratospheric ozone, The atmospheric re-analysis done by were assimilated. The Climate Prediction stratosphere. and better characterizes cryospheric SMHI with the HARMONIE system and Center (CPC, NWS/NOAA) requires the ALADIN model at 11Km is used to a modern reanalysis to replace the
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 46 Section 1 processes. In this talk we will present (HErZ). The HErZ branch on climate results relating to the introduction of An overview on regional monitoring is a research group located Creating a sea ice reanalysis aerosols in MERRA-2. reanalysis activities based at University of Bonn and University of using an ocean model forced by Cologne, funded by DWD. The aim is The assimilation of Aerosol Optical Depth on the COSMO model surface fields from atmospheric to analyze the potential of the regional (AOD) in GEOS-5 involves very careful reanalyses Author Frank Kaspar reanalysis system as a tool for climate cloud screening and homogenization Affiliation Deutscher Wetterdienst monitoring of DWD. (2) Within the EU- Author Thomas Collow of the observing system by means of funded project UERRA an approach for a Neural Net scheme that translates Co-authors Affiliation INNOVIM, LLC/NOAA an COSMO ensemble reanalysis was MODIS and AVHRR radiances into S. Wahl (Hans-Ertel-Centre for Climate Prediction Center developed. AERONET calibrated AOD. The system Weather Research, University of Bonn), Co-authors also assimilates MISR and AERONET J. Keller (Hans-Ertel-Centre for Weather Within that project, a dataset with 12 km Wanqiu Wang (NOAA Climate Prediction AOD observations. Research, University of Bonn, Deutscher resolution is currently produced and will Center), Arun Kumar (NOAA Climate Wetterdienst), M. Borsche (Deutscher be compared to regional reanalyses of Prediction Center) These measurements are further quality Wetterdienst), M. Lockhoff (Hans-Ertel- other European partners. Both activities controlled using an adaptive buddy A new Arctic sea ice reanalysis product Centre for Weather Research, University have a strong focus on the evaluation check scheme, and assimilated using is being developed at the NOAA Climate of Bonn), A. K. Kaiser-Weiss (Deutscher of the datasets. There is strong interest the Local Displacement Ensemble (LDE) Prediction Center (CPC), which will Wetterdienst), D. Niermann (Deutscher in the datasets from various sectors, methodology. be used to initialize sea ice forecasts. Wetterdienst), A. Hense (Hans-Ertel- especially the energy sector. Therefore, Experimental Arctic sea ice outlooks We will present a summary of our efforts Centre for Weather Research, University one focus of the evaluation activities are have been produced at CPC since 2015 to validate the MERRA-2 aerosols. of Bonn), S. Crewell (Hans-Ertel-Centre parameters that are relevant for such using sea ice thickness initialization data The GEOS-5 assimilated aerosol fields for Weather Research, Unversity of applications. from the Pan-Arctic Ice Ocean Modeling are first validated by comparison to Cologne) In this presentation we will provide an and Assimilation System (PIOMAS). independent in-situ measurements The COSMO model (Consortium overview of the reanalysis system, the Our plan is to replace PIOMAS with a (PM2.5 concentrations, long term surface for Small-scale Modeling) is a non- datasets, evaluation results with focus new product that is consistent with the dust concentrations, Maritime Aerosol hydrostatic limited-area atmospheric on the user-relevant parameters and forecast model used (Climate Forecast Network, airborne and ground based model, that is used for operational and ongoing activities. Further details on System version 2). lidars, UV based measurements, etc.) for research applications by Germany’s specific evaluation activities will be We will conclude with a discussion of To develop this new product, Meteorological Service (Deutscher addressed in separate presentations. our plans to extend the historical aerosol Wetterdienst, DWD) and other members experiments have been conducted observing system in future GMAO of the consortium (see http://www. with the Geophysical Fluid Dynamics reanalyses. cosmo-model.org/). Laboratory Modular Ocean Model version 5 (MOM5). Here we will present The model was also used to generate a results from these experiments, set of regional reanalysis datasets within highlighting the impacts of using different two activities: (1) A 6km deterministic surface boundary conditions, namely reanalysis for the European CORDEX- from the Climate Forecast System domain and a 2 km reanalysis for Central Reanalysis (CFSR) and Modern-Era Europe was produced within the Hans- Retrospective analysis for Research Ertel-Centre for Weather Research and Applications, version 2 (MERRA2).
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 47 Section 1
Also shown will be the impacts of using kinematical consistency, allowing for the scope and usability of the ECCO that is planned to be continued in Near- different vertical resolutions for the top instance for budget closures in terms of Central Estimate will be expanded in Real-Time through the C3S operational layer of the ocean (10m and 1m), as well explicit physical processes, and making support of the broader climate change service. as the impacts of different sea surface amenable investigations of attribution science community, for instance, by the It is also expected that in a second phase temperature restoring datasets, including and causation of the oceanic state. development of an open source adjoint of production this dataset will be back those from the National Climatic Data of the ocean model, valuable for diverse This presentation describes the status extended to the year 1950. ERA5-Land Center (NCDC) and the Operational applications. These products and future and plan of ECCO’s flagship product, will be the result of a single simulation Sea Surface Temperature and Sea Ice plans for the ECCO Central Estimate will the Central Estimate. “ECCO Version 4” driven by near-surface atmospheric Analysis (OSTIA). Finally, we will share be discussed. represents the Consortium’s ongoing fields from ERA5 atmospheric reanalysis results from the assimilation of sea ice Central Estimate. First established in and climatic fields at native resolution. concentration observations from the 2015, Version 4 is of moderate spatial Additionally, near surface temperature and NASA Team dataset into the model. ERA5-Land: a new state-of-the- resolution (40-100km) but with a domain art global land surface humidity fields will be adjusted using daily that is truly global, including the Arctic reanalysis dataset computed environmental lapse-rates. Ocean. Recent enhancements include ECCO-Sea Level: The next phase One of the added values of ERA5-Land use of new observations (e.g., GRACE Author Joaquin Munoz Sabater in the “Estimating the Circulation with respect to the ERA5 atmospheric ocean bottom pressure and Aquarius sea and Climate of the Ocean” Project Affiliation ECMWF reanalysis is a global projected horizontal surface salinity), model improvements Co-authors resolution of approximately 9 km (around Author Ichiro Fukumori (e.g., geothermal heating, sea ice model), E. Dutra (Instituto Dom Luiz, Faculdade 4 times finer resolution than ERA5), and additional controls in the estimation Affiliation JPL/Caltech de Ciências, Universidade de Lisboa), matching the current operational ECMWF (e.g., mixing coefficients, correlated Co-authors G. Balsamo (ECMWF, Reading, UK), TCo1279 operational grid, and therefore uncertainties), that result in a more P. Heimbach (Univ. Texas Austin), S. Hirahara (Global Environment and providing consistent input for Numerical complete and accurate estimate than C. Hill (MIT), D. Menemenlis Marine Department, Japan Meteorological Weather Prediction and climate studies before. (JPL/Caltech), R. M. Ponte (AER) Agency), H. Herbasch (ECMWF, Reading, involving land water resources, but Efforts are underway to further advance UK), S. Boussetta (ECMWF, Reading, also for downstream applications such The “Estimating the Circulation the Central Estimate to study Earth’s UK), C. Albergel (CNRM, Météo-France), as those based on hydrological and and Climate of the Ocean” (ECCO) climate with a focus on improving D. Dee (ECMWF, Reading, UK) agricultural modeling. Consortium has pioneered in the understanding and prediction of global advancement of ocean state estimation. The European Centre for Medium ERA5-Land will also include, for the first and regional sea level variability and The ECCO estimates combine nearly Range Weather Forecasts (ECMWF) is time, an estimation of key land-variables change. The new initiative, called all extant observations of the ocean implementing, on behalf of the European uncertainty based on meteorological “ECCO-Sea Level”, will incorporate with a state-of-the-art ocean general Commission, the Copernicus Climate forcing and model parameters capabilities for coupled ocean and circulation model spanning the globe, Change Service (C3S, http://climate. uncertainties supplied by a 10-member ice sheet estimation to improve the by adjusting its atmospheric forcing copernicus.eu/). Among its portfolio of ensemble parallel run, hence providing estimate’s representation of ocean-ice and other independent controls, over product, C3S is developing the ERA5- vital information to land-surface data interaction pertinent to sea level rise. the modern observational era from Land dataset, a new, state-of-the-art, assimilation systems. The offline nature the beginning of continuous satellite The estimation’s spatial resolution will high-resolution, global, hourly land- of land reanalysis allows to incorporate altimetry measurements in the early also be refined to eddy-permitting scales surface dedicated reanalysis dataset forefront model developments before the 1990s to the present. The estimates are to better resolve the energetic variations from 1979 (beginning of the satellite era) production phase. characterized by their dynamical and of the circulation. Simultaneously,
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 48 Section 1
For example, ERA5-Land could benefit monthly HadISST reconstructed fields. The comparison between the two SST from a larger discretization of the soil Both reanalysis systems are forced assimilation strategies shows that both Land Surface Reanalysis in layer permitting better propagation of by the NOAA/CIRES 20th Century direct assimilation and nudging scheme the CMA 40-year Reanalysis the energy and water fluxes through Reanalysis version 2 (20CRv2) and have their advantages and disadvantages the vertical dimension of the soil layer the ECMWF ERA-20C, thus forming and a combination of these two schemes Author Xiao Liang (currently under development). This an ensemble of four realizations, plus is desirable in future work. Affiliation CMA paper presents the methodology that control experiments. Finally, the uncertainty of the reanalyses Co-authors will be used to produce the ERA5-Land Due to large biases at high latitudes, heat content due to the different Lipeng Jiang (Affilation 2), Chunxiang Shi dataset, as well as its main strengths corrections are applied to the 20CRv2 atmospheric forcing is assessed by (Affilation 3), Zhiquan Liu (Affilation 4) and weaknesses. atmospheric forcing, based on the comparing the root mean square The land surface interacts with weather First results obtained from demonstrative comparison with ERA-Interim during difference (RMSD) between pair of and climate through regulation of the scout-runs will be shown and discussed, the overlapped period. The reanalyses experiments that share the same water and energy fluxes at the land- and their performance will be assessed are designed to investigate the impact assimilation configuration but are forced atmosphere interface. For example, soil by comparison to in-situ data and other of different strategies for constraining by different atmospheric reanalyses. moisture is important for the partitioning long-term available datasets. the SST in long-term assimilation It turns out that the upper ocean (top of the surface energy between latent, experiments, the feasibility of assimilating 700m) heat content RMSD when in-situ sensible and soil heat fluxes, and subsurface observations in the same profiles are assimilated is significantly hence affects the soil temperature Historical ocean reanalyses kind of experiments, and the impact of smaller than the control experiments and subsequently the near-surface air (1900-2010) using different the atmospheric forcing. In general, these RMSD even during the first half of the temperature. The development of land data assimilation strategies ocean reanalyses are able to capture XX century, meaning that even a poor surface reanalysis methods and long- trends and variability of some key ocean and atmospheric forcing observing network is able to reduce time-series land data products is critical parameters. for improving weather and climate Author Chunxue Yang the atmospheric forcing uncertainty. A warm bias of SST with 20CRv2 in the Conversely, the total column heat content forecasts. Affiliation ISAC-CNR first half of the century leads to incorrect remains unconstrained with respect to The presentation will discuss current Co-authors long-term trends, even though SST the atmospheric forcing uncertainty until developments and future plans of the Simona Masina (The Euro-Mediterranean anomalies are realistically captured. the mid 1950s. CRA-40/land reanalysis, which is a Center on Climate Change, Bologna, Heat contents at 0-300m, 0-700m and supplemental land surface reanalysis Italy ) and Andrea Storto (The Euro- 0-2000m have an increasing trend in all system and data product of the CMA 40- Mediterranean Center on Climate experiments, consistent with available year Reanalysis (CRA-40), generated at Change, Bologna, Italy) observation-based products (NODC the China Meteorological Administration. A set of historical ocean reanalyses heat content dataset) during the second CRA-40 is initiated in 2014, which aims covering the period from 1900 to 2010 half of the century. In order to reproduce to construct the China’s first global are performed and analysed. All the realistic mass transport, mixed layer atmospheric reanalysis system and reanalyses assimilate vertical profile depth and eddy kinetic energy, it is produce a long-time-series product observations with a 3D-Var assimilation necessary to assimilate vertical profile since 1979. scheme but differ in the way they use data, although this leads to some SST data, which are either assimilated discontinuities in the reanalysis ICOADS observations or nudged to time series.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 49 Section 1
Earth system concept of CERA-20C, by the horizontal resolution of about 30km analysis of surface parameters including Land-atmosphere weakly coupled accounting for the full observing system and the time frequency of 6 hours. screen level temperature, 10m wind and by including land data assimilation. speeds, mean sea-level pressure (MSLP), assimilation in CERA-SAT The products especially the estimates soil temperatures, soil moisture and 24 In CERA-SAT the land-atmosphere data of soil moisture, ground temperature Author Patricia de Rosnay h rainfall accumulations. The quality assimilation is weakly coupled, using a and soil temperature are assessed Affiliation ECMWF of the 3-D variational data assimilation coupled land-atmosphere background by comparing with a large number of used in the reanalysis is also assessed. Co-authors forecast and separate analyses for the ground-based observations. Compared Preliminary analysis shows that it takes D. Schepers (ECMWF), atmosphere and for the surface (screen with other land surface reanalysis almost 12 months to spin up the deep P. Dahlgren (ECMWF) level variables, soil moisture and snow). products, the hallmark of CRA-40/ soil in terms of moisture, justifying the Conventional and satellite observations land is the use of much more observed The CERA-SAT coupled climate choice of running year-long spin up that inform on the state of both precipitation in China to drive the land reanalysis for the satellite era (see periods. presentation by Schepers et al.) is a key subsystems are assimilated. surface model. CRA-40/land has not yet benefit from the assimilation of land Overall, the model performed product of the ERA-CLIM2 European They are located at the land-atmosphere surface observations. The advantages, consistently over the time period. project. It relies on an Earth System interface and include two-meter challenges and future plans of Small biases were found in screen- approach focusing on atmosphere, temperature and relative humidity, snow assimilation observations into the system level temperatures, MSLP and 10m ocean, waves, land, and sea ice. In depth, and soil moisture. In this poster will be discussed in the presentation. wind speed. Soil temperatures are CERA-SAT different data assimilation we present the land-atmosphere weakly well represented by the model. 24 h methods are used for the each coupled assimilation approach used in accumulations of precipitation generally component of the Earth System. CERA-SAT. Met Éireann high resolution exhibit a small positive bias of 1mm per A hybrid four-dimensional variational Perspectives of coupling enhancement reanalysis for Ireland day and negative biases over mountains data assimilation (4D-Var) is used for the using EDA-based (Ensemble Data Author Emily Gleeson due to a mismatch between the model atmosphere, a 3D-Var with the first guess Assimilation based) cross correlation orography and the geography of the Met Éireann at appropriate time (FGAT) is used for estimates and land-atmosphere coupling Affiliation region. MÉRA outperforms the ERA- the ocean analysis, and a combination of at the outer loop level with 4D-Var are Co-authors Interim reanalysis, particularly in terms Optimal Interpolation (OI) and simplified discussed as perspective for future E. Whelan (Research, Environment of standard deviations in screen-level Extended Kalman Filter (EKF) are used generation of coupled reanalyses. and Applications Division, Met Éireann, temperatures and surface winds. This for the land surface. Dublin, Ireland), J. Hanley (Research, dataset is the first of its kind for Ireland CRA-40/land is an off-line subsystem of CERA-SAT relies on a pioneering coupled Environment and Applications Division, and is now publically available. CRA-40, which is designed to provide Met Éireann, Dublin, Ireland) ocean–atmosphere data assimilation land surface components such as approach (as does CERA-20C, the ground temperature, soil moisture, snow, The Irish Meteorological Service, Met coupled climate reanalyses of the 20th etc. CRA-40/land system is constructed Éireann, has carried out a 35-year very century, see presentation by Laloyaux based on the LIS (Land Information high resolution (2.5 km horizontal grid) et al.), with the ocean 3D-Var coupled System) which is developed primarily regional climate reanalysis for Ireland to the atmospheric 4D-Var at its outer by NASA and has been used in CFSR- using the ALADIN-HIRLAM numerical loop level. CERA-SAT also extends the land reanalysis. A 10-year CRA-40/land weather prediction system. Here we experimental product is produced with provide an overview of the reanalysis, called MÉRA, as well as a preliminary
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 50 Section 1
reproduced the variability of ocean and The model component is the NEMO Multi-year consistent reanalysis biogeochemical parameters in important Performance and quality platform driven at the surface by ECMWF of physical and biogeochemical dynamic processes (e.g. the inflow assessment of the Copernicus ERA-Interim reanalysis. Observations are variables in the North Sea and process). However, it was found that the Marine Service global ocean assimilated by means of a reduced-order Baltic Sea model simulation yielded obvious biases, eddy-resolving physical Kalman filter with a 3D multivariate modal especially in the deep layers. decomposition of the background error. Author Ye Liu reanalysis GLORYS12V1 As expected, the assimilation has Affiliation SMHI been found to impart significant Author Jean-Michel Lellouche Performance and quality Co-authors positive impact in both the physical Affiliation Mercator Océan assessment of the global ocean Lars Axell (Swedish Meteorological and biogeochemical simulations. For Co-authors eddy-permitting physical and Hydrological Institute) example, with the comparison with O. Le Galloudec (Mercator Océan), observations, the oxygen, nutrients, reanalysis GLORYS2V4. A multi-year physical and biogeochemical E. Greiner (CLS), G. Garric (Mercator temperature and salinity biases in reanalysis was carried out in the Baltic Océan), C. Regnier (Mercator Océan), Author Gilles Garric reanalysis at the Baltic proper has been Sea and North Sea. The model system is M. Drevillon (Mercator Océan), Affiliation Mercator Océan significantly reduced relative to reference R. Bourdalle-Badie (Mercator Océan), based on the Swedish coastal and ocean Co-authors run. Furthermore, the reanalyzed hypoxia C. Bricaud (Mercator Océan), Y. Drillet biogeochemical model (SCOBI) coupled L. Parent (Mercator Océan), E. Greiner in the Baltic Sea is closer to the observed (Mercator Océan), P.-Y. Le Traon to the NEMO-Nordic circulation model (CLS), M. Drévillon (Mercator Océan), one relative to the reference run. (Mercator Océan) (Hordoir et al., 2015). A weak coupled M. Hamon (Mercator Océan), data assimilation system based on a The results denoted that as a Over the past years, Mercator Océan J.M. Lellouche (Mercator Océan), sequential ensemble interpolation kalman consistent reanalysis of physical and has been regularly upgrading its global C. Régnier (Mercator Océan), filter (SEIK) was adopted to merge the biogeochemical in the Baltic Sea and ocean physical reanalysis through C. Desportes (Mercator Océan), information of model and observations. North Sea, the output data set of this improvements in the ocean model, O. Le Galloudec (Mercator Océan), reanalysis can inform the management of The high resolution remote sensing assimilation scheme and assimilated C. Bricaud (Mercator Océan), Y. Drillet the North Sea and Baltic Sea ecosystem. sea surface temperature, salinity and data sets. The last upgrade concerned (Mercator Océan), F. Hernandez (Mercator For exampling the analysis or prediction temperature profiles, oxygen and the eddy-permitting reanalysis Océan), C. Dubois (Mercator Océan) of the trend and reason of oxygen nutrient profiles observations were GLORYS2V4 (1/4° horizontal resolution and P-Y. Le Traon (Mercator Océan) deficiency potentially threatening. and 75 vertical levels) covering the assimilated into the NEMO-SCOBI. The The last upgrade of global ocean reanalysis altimetry era (1993-2016). R&D activities observation errors were decreased with GLORYS2V4 produced at Mercator Océan have been conducted at Mercator Océan increasing the water depth. In order to that covers the altimetry era (1993-2016) in 2016/2017 in order to propose, in produce dynamic consistent analysis, has been performed in the framework the framework of Copernicus Marine both physical and biogeochemical of Copernicus Marine Environment Environment Monitoring Service observations were assimilated in the Monitoring Service (CMEMS; http://marine. (CMEMS), an eddy-resolving physical same time. copernicus.eu/). The reanalysis is run at reanalysis called GLORYS12V1, covering eddy-permitting resolution (1/4° horizontal Based on the numerical experiment with the same time period and based on resolution and 75 vertical levels) with the and without data assimilation, the inter- the current real-time global forecasting NEMO model and driven at the surface comparison was implemented to validate CMEMS system (1/12° horizontal by ERA-Interim reanalysis. the reanalysis results. The model has resolution and 50 vertical levels).
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 51 Section 1
The reanalysis system uses a multi-data will allow the representation of deep and multivariate reduced order Kalman SPHERA (High Resolution convection and temporal resolution Status of ERA5 Reanalysis filter based on the singular extended REAnalysis over Italy): plan will be sufficient to resolve the diurnal Operational Production at evolutive Kalman (SEEK) filter formulation and setup cycle. The dataset will cover the ECMWF together with a 3D-VAR large scale bias period 1979-2016. Specific tests will correction. The assimilated observations Author Ines Cerenzia be undertaken in order to compare a Author Raluca Radu are along-track satellite altimetry, sea Affiliation ARPAE-Emilia Romagna subset of SPHERA archive with the high- Affiliation ECMWF surface temperature, sea ice concentration Co-author resolution observative analysis derived Co-authors and in-situ profiles of temperature and Tiziana Paccagnella from the regional networks over Italy (e.g. P. Berrisford (ECMWF), A. Bonet salinity from CORA data base. (ARPAE-Emilia Romagna) ERACLITO Antolini et al. 2015, ARCIS (ECMWF), H. Hersbach (ECMWF), Pavan et al. 2013, EURO4M-APGD Isotta J. Hodkinson (ECMWF), A. Horanyi With respect to the previous version, In a framework of developing interest et al. 2014). (ECMWF), C. Soci (ECMWF) GLORYS2V4 contains the following of EU Community towards high resolution and M. Suttie (ECMWF) main improvements: a) a new initial regional reanalysis, ARPAE-SIMC The project aims at having a high temperature and salinity conditions proposes the development of SPHERA resolution, space and time consistent, The ERA5 Reanalysis, the successor of derived from EN4.1.1 data base and better (High Resolution REAnalysis over monitoring of past decades climate ERA-Interim Reanalysis, is a state-of- balanced with altimetry, b) the use of the Italy), the first dynamical downscaling over Italy and its surrounding Seas at the-art reanalysis covering the satellite updated delayed mode CORA4.1 in situ reanalysis of the atmosphere centred the same time for climatic assessments era (1950 – present). It is currently observations from CMEMS, c) a better over Italy with a horizontal resolution (trend along the past years, climate produced at ECMWF in the framework of observation operator in the assimilation of 2.2km and a high frequency. reference for COSMO applications in the Copernicus Climate Change Service scheme for altimetry observations d) a different scenarios associated to Climate (C3S). ERA5 is the first reanalysis to be The Italian reference NWP model for new hybrid Mean Dynamical Topography Change over Italy) and for feeding produced operationally as a service, operational limited area forecast, i.e. (MDT) referenced over the 1993-2013 downstream high-resolution model rather than as a research project. With the COSMO (Consortium for small scale period, e) an updated correction of large applications. The project is expected to respect to its predecessors, ERA5 modelling) model will be applied to scale atmospheric surface precipitations be accomplished within the end of 2019 benefits from various improvements perform the dynamical downscaling. fluxes and f) an update of the global in the data assimilation, model and climatological runoff data base together This effort will complement the activity of observing systems from recent years. For with a better account of freshwater fluxes the DWD, Deutscher Wetterdienst, and of the historical period production is divided from polar ice sheet’s glaciers. the University of Bonn on the same field, into parallel streams, each spanning a The new reanalysis outperforms the since the initial and boundary conditions period of 10 years, while for the present previous version in many aspects and will be based on the COSMO-REA6 time ERA5 is produced daily near to real the presentation will give an overview reanalysis archive (Bollmeyer et al. 2015), time (NRT). a 6 km-resolution reanalysis project of main results. The new altimetry and Each stream comprises a lower covering the CORDEX european domain water masses equilibrium in the system resolution 10 member 4D-Var ensemble that is currently in production. particularly improves the representation (EDA) providing flow-dependent of global thermo-haline content with a The assimilation of the upper air and background error information to the trend of +3.56 mm/year for Global Mean surface conventional observations will high resolution (HRES) deterministic Sea Level together with a +1.8 mm/year be performed by using the continuous assimilation cycle. The overview of the for the thermo-steric signal. nudging technique. Horizontal resolution production system and the current status
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 52 Section 1 of the operational production, which and sea ice data assimilation; updated Re-analysis ensemble product (GREP). started in 2016, will be presented. The forcing and observation datasets; The current version of this re-analysis Towards a high-resolution results are continuously monitored using and implementation of a generic centres around the NERC/Met Office probabilistic regional reanalysis a system of diagnostic and monitoring perturbation scheme that accounts Joint Ocean Modelling Programme system based on a local tools. Currently, the ERA5 Reanalysis for representativeness errors from (JOMP) Global Ocean 5.0 (GO5.0) and the ensemble transform Kalman dataset is partially available and will observation and structure and analysis NERC/Met Office Joint Sea Ice Modelling provide a large number of essential errors from surface forcing fluxes. Programme (JSIMP) Global Sea Ice version filter climate variables within the C3S climate 6 (GSI6). The operational implementation of Author Thomas Roesch data store (CDS). real-time extension of ORAS5 is also A planned update to an improved version Affiliation Deutscher Wetterdienst discussed; this provides ocean and sea- GO6/GSI8 version is expected within the Co-authors The ECMWF ocean-sea ice ice initial conditions for the ECMWF’s next calendar year. The new version, based Lilo Bach (DWD), Roland Potthast (DWD), reanalysis system ORAS5 and coupled ensemble forecasting system on NEMO vn3.6 and CICE 5.1 will include Frank Kaspar (DWD), Jan Keller (DWD, operational ocean analysis (spanning the medium range, monthly a variable volume level scheme for the Uni Bonn) and seasonal forecasts ranges). Results ocean, a parameterisation for under-ice- Author Hao Zuo from evaluation of ORAS5 with observed shelf melt, pronostic icebergs, and a multi- The question of high-impact weather and its relation to climate change today is of Affiliation ECMWF data, e.g. using RAPID-derived transport layer sea ice thermodynamic scheme along and re-processed sea-level data are with an improved representation of melt- tremendous importance for all parts of Co-authors also discussed, with the focus on some ponds. We will show some initial results our modern world. It touches all basic M. A. Balmaseda (ECMWF), K. Mogensen prominent climate signals. from this latest configuration, contrasting layers of a modern society, from logistics (ECMWF), S. Tietsche (ECMWF), and comparing the advancements over and production to national safety,from P. de Rosnay (ECMWF) previous versions in terms of several ocean renewable energy political strategy and A new operational Ocean ReAnalysis The GloSea/FOAM ocean and and sea ice monitoring indicators such as daily energy supply to personal holiday System 5 (ORAS5) has been sea ice re-analysis: Current heat and salt content, surface currents, sea planning. National weather services implemented at ECMWF. It spans status and future plans ice volume, along with root mean square and research institutions are reacting the period 1979 to present and was errors with the ingested observations. to the increasing need to estimate risk Author K. Andrew Peterson produced using NEMO Ocean Model Additionally, recent advancements towards and distributions of both standard coupled to LIM2 sea ice model. Affiliation Met Office the assimilation of sea ice thickness to variables of weather and climate such Subsurface in-situ observations from Co-authors satellite observations will be presented. as temperatures or humidity and high- EN4, SLA from AVISO DUACS2014, C. MacLachlan (Met Office), C. Harris Our current systems only assimilate sea impact phenomena such as strong SST from HadSST2/OSTIA and Sea (Met Office), A. Aguiar (Met Office), ice concentration, allowing model physics precipitation, wind gusts and storms, Ice Concentration from OSTIA were M.J. Martin (Met Office), E. Blockley to integrate the thickness properties of the tornados, hurricanes or fog. assimilated in ORAS5 using NEMOVAR (Met Office) sea ice. This has been shown to depend on The agenda of weather and climate Ocean data assimilation system (in 3DVar the external forcing applied to the model, As part of the seasonal forecast system forecasting and projection today includes FGAT approach). and has lead to inconsistencies between at the Met Office, a 1/4 degree ocean and the development and operation of the Met Office real time sea ice analysis Here we describe the most important sea ice analysis is performed for 1990 ensemble forecasting systems (EPS) on and re-analysis. Assimilation of the sea ice system upgrades in ORAS5, including to near real time. This analysis is one of all scales, which have the ability to model will create better consistency, along with increase of model resolution; change 4 members of the Copernicus Marine and describe the distribution of possible a better sea ice thickness climatology. to a coupled ocean-sea ice model Environment Monitoring Service Global
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 53 Section 1 events and as such the variability of at about 30 km. This gives much more extreme weather, its variables and UERRA SMHI HARMONIE- detail in precipitation, temperature and phenomena. ALADIN high resolution Regional wind near the surface. We describe the setup of the ensemble Reanalysis over Europe for The system is very efficient and parallel data assimilation (EDA) and forecasting 1961-2015 10 year streams were run with 4 months systems which have been developed at spin up periods. The output data, Author Per Undén DWD, including the ICON global model including observation statistics, are with its hybrid ensemble variational data Affiliation SMHI stored on ECFS at ECMWF but the fields assimilation (EnVAR) and the ensemble Co-authors have been archived in the common prediction system ICON-EPS as well Martin Ridal (SMHI), Esbjörn Olsson UERRA MARS archive. The reanalysis as the high-resolution ensemble data (SMHI), Jelena Bojarova (SMHI), Klaus will be presented and compared to assimilation system COSMO-KENDA Zimmermann (SMHI), Heiner Körnich the ERA reanalyses together with the (Kilometer Scale Ensemble Data (SMHI) and Eric Bazile (Météo-France) different data types stored, as well as Assimilation). observation usage and diagnostics using SMHI is coordinating the FP7 Project a partly newly developed observation The latter is the operational system of UERRA (Uncertainties in Ensembles monitoring system. DWD and used by further members of of Regional ReAnalyses) which has the COSMO consortium. It drives the developed three full upper air Regional high-resolution ensemble forecasting European Reanalysis systems and two system COSMO-DE-EPS. We 2-dimensional ones. The project is now demonstrate the high quality of the in its final phase and all data is archived system. in an openly available UERRA archive with common parameters within MARS We will then give perspectives on the use at ECMWF. of the coupled ICON-EPS COSMO-EPS ensemble system for the investigation At SMHI historical data assimilation and of climate variability for reanalysis forecast cycles have been produced and climate projection, which is under for the period 1961 until 2015 using the investigation by DWD core teams in HARMONIE-ALADIN system. It has been collaboration with the Hans-Ertel center run at 11 km horizontal resolution with HErZ in Bonn. 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 km respectively or even the current ERA5
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 54 of velocity and the CNES-CLS13 Mean means of the Satellite Application Facility in June the Arctic albedo of the Canadian Section 2 – Dynamic Topography. Ekman currents on Climate Monitoring (CM SAF, funded coast has slightly increased since Observations at two levels (surface and 15m) are by the European Organisation for the 2008/2009. calculated from an empirical model. The Exploitation of Meteorological Satellites The maximum increase of the June for reanalyses model parameters (amplitude and angle) (EUMETSAT)) data record CLARA-A2 albedo during 1982/1983 – 2014/2015 have been derived as to minimize the SAL (CM SAF cLoud, Albedo and surface is 0.55 and the maximum decrease is misfit between wind stress data and the RAdiation dataset from AVHRR data – A 24 year observation-based -0.51. During 2008/2009 – 2014/2015 ageostrophic component extracted from Edition 2, surface albedo), which covers reanalysis of ocean surface the corresponding increase for albedo in in-situ drifter velocities (SVP drifters at the years from 1982 to 2015, in the currents from the GlobCurrent August is 0.30 and the decrease -0.40. 15m depth, Argo floats at the surface). resolution of 0.25° (global product). The project SAL albedo contains contributions both A regional product for the Mediterranean from the sea ice and the open ocean. Author Marie-Hélène Rio Sea has also been produced over the Assessing the impact of GPS The previous CLARA-A1-SAL release Affiliation CLS same time period. Obtained currents radio occultation measurements already showed a dramatic decrease have been validated through comparison in ERA5 Co-authors in the surface albedo of the Arctic sea to independent in-situ observations and C. Dufau (CLS), H. Etienne (CLS), S. Mulet ice area during 1982-2009. Variations in Author Sean B. Healy other existing products based either on (CLS), G. Larnicol (CLS), J. Johannessen mean sea-ice albedo could be explained observations or model outputs. Affiliation ECMWF -NERSC), C. Donlon (ESA) using sea-ice concentration, surface air Co-authors temperature and elapsed time from onset Accurate estimate of ocean surface A Horanyi (ECMWF), of melt as drivers. currents is both a challenging issue Arctic sea ice albedo time series A J Simmons (ECMWF) and a growing end-users requirement. 1982-2015 according to the The CLARA-A2 SAL data set shows a GPS radio occultation (GPS-RO) Advancing the quantitative estimation CLARA-A2-SAL product continuation of the albedo decrease in the measurements are now a key of ocean surface currents from satellite Siberian and Scandinavian coasts during by CM SAF observation type forclimate reanalyses. sensor synergy and demonstrating the 2009-2015, whereas the Canadian coast They can be assimilated without impact in user-led scientific, operational Author Terhikki Manninen shows an albedo increase from 2009 to bias correction, and they perform and commercial applications was the Affiliation Finnish Meteorological 2015. The maximum increase of the August the role of “nchor measurements” in main objective of the GlobCurrent Institute albedo during 1982/1983 – 2014/2015 variational radiance bias correction project, a Data User Element (DUE) from is 0.32 and the maximum decrease is Co-authors schemes. The measurements provide the European Space Agency (ESA) which -0.40. During 2008/2009 – 2014/2015 K. Anttila (Finnish Meteorological accurate temperature informationin the run from October 2013 to June 2017. the corresponding increase for albedo in Institute), T. Manninen (Finnish upper troposphere and lower/middle August is 0.31 and the decrease -0.27. In the framework of this study, a global Meteorological Institute), E. Jääskeläinen stratosphere. reanalysis of 24 years (1993-2016) of (Finnish Meteorological Institute), The variation of the Arctic surface Furthermore, they have improved the global ocean currents at two depths A. Riihelä (Finnish Meteorological albedo in June in 1982/1983 – 2014/2015 consistency between stratospheric (surface and 15m) has been calculated Institute) shows a decrease in a larger area, thus as the sum of the geostrophic and temperature reanalyses since 2007, A new 34 –year long time series of surface indicating that the sea ice concentration Ekman components. The geostrophic when GPS-RO numbers increased with albedo was used to study the changes in has decreased also in June. In Hudson component is based on the SSALTO- the introduction of COSMIC data. In the albedo of the Arctic sea ice. The study Bay the location of sea ice changed from DUACS multi-mission altimeter maps this talk we review the measurement is based on the surface albedo monthly the western side to the eastern side. Also
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 55 Section 2 technique, and describe how GPS-RO in-situ profiles for instance or which In this framework, ARMOR3D have been Predictions regarding the future climate measurements are assimilated in ERA5. offer only a surface view of the ocean as compared with 6 other global ocean and the state of African tropical forest We will demonstrate that the GPS-RO satellite data. reanalysis/reprocessing products of remain uncertain in part due to a lack measurementsreduce stratospheric CMEMS: an optimal interpolation of in- of legacy data which provides the The originality of the ARMOR3D biases in ERA5, and that GPS-RO situ T/S profiles (CORA-OI from Coriolis), necessary climatological and ecological observation based product is to take and AMSU-A channel 14 provide 4 reanalysis (GLORYS2V4 from Mercator context for current research in the Congo advantage of the strengths of these 2 complementary information. Océan, ORAS5 from ECMWF, FOAM/ Basin. Even today, the central Congo types of data by combining satellite GloSea from Met Office and C-GLORS Basin is currently represented by only a More specifically, it will be demonstrated SLA and SST datasets with in-situ T, S from CMCC) and the ensemble mean of few rain gauges, limiting climate forecasts that AMSU-A channel 14 can constrain vertical profiles in order to build a global these reanalysis (GREP). across the Congo Basin. This lack of biases in the GPS-RO “null-space”. We 3D weekly temperature, salinity and long-term (historical) climatological data will also present new results assessing geostrophic velocities fields at a spatial In this presentation, the main steps of leaves the central Congo Basin spatially the quality and impact of data from 1/4° resolution. the ARMOR3D and the combined SSS/ and temporally under-represented. GPS/MET mission from 1995-1997. SSD production systems are described. The mesoscale content of the satellite However, old climate records could Although the GPS/MET data availability Then, results from ocean reanalysis/ data and the vertical sampling of the provide valuable information in support is sporadic, we will show that it is still reprocessing intercomparison are in-situ profiles are complementary in this of climate re-analysis. a useful dataset for testing reanalysis presented: hydrographic variability are statistical approach. Also, this method systems during this period. analyzed in all products in terms of spatial The historical archives of La régie des need to use a reliable mesoscale SSS patterns and time evolution. Robust plantations de la colonie (REPCO) field. We use the combined SSS/SSD features and weaknesses are highlighted and the Institut National d’Etudes field computed at CNR from an optimal CMEMS multi-observations and uncertainty levels are provided. Agronomique du Congo Belge (INEAC), interpolation of in-situ data using SST products to monitor ocean state cover six decades (1901–1960). Located gradients to add mesoscale features. at the State Archives of Belgium, the Author Sandrine Mulet ARMOR3D and the combined SSS/SSD COBECORE: recovering (eco-) Royal Museum for Central Africa and CLS products are part of the Copernicus Affiliation climatological data from Belgian the Botanic Garden Meise, they hold Marine Environment Monitoring Service Co-authors colonial archives. vast amounts of (eco-) climatological (CMEMS) through the Global observation Stéphanie Guinehut (CLS), Nathalie data, with great potential and relevance component of the Global Monitoring and Author Koen Hufkens Verbrugge (CLS), Bruno Buongiorno- for basic and applied research in the forecasting center. Nardelli (CNR), Riccardo Droghei (CNR), Affiliation Harvard University central Congo Basin. Marie Drévillon (Mercator-Océan), A full reprocessing from 1993 to 2016 Co-authors Their scientific value resides in the Jérome Gourrion (CNRS/Coriolis), and near-real-time fields since 2014 are Kim Jacobsen (1), Hans Beeckman (1), extent of the data collected in a Andrea Storto (CMCC), Hao Zuo available through the CMEMS web portal. Piet Stoffelen (2), Filip Vandelook (2), region where the availability of reliable (ECMWF), Drew Peterson (UK Met Office) The range of applications of this product Jan Van den Bulcke (3), Michael Amara (4), baseline measurements are practically goes from mesoscale to large-scale Hans Verbeeck (5). To have a synoptic view of the 3D absent. The COBECORE project (http:// studies. It could be used both for the ocean to pursue oceanic studies, a 1: Xylarium, Royal Museum for Central cobecore.org) aims to establish baseline evaluation of re-analyses and for ocean multi observations gridded product can Africa, 2: Botanic Garden Meise, climatological measurements, crucial for climate studies. For instance, ARMOR3D be often useful instead of using raw 3: Laboratory of Wood Technology, Ghent reanalysis, by valorizing climatological contributes to the annual CMEMS Ocean observations which can be irregularly University, 4: State Archives Belgium, legacy data through computer vision, State Report (OSR). distributed in space and time as the 5: CAVElab, Ghent University machine learning and citizen science
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 56 Section 2 approaches. Here we report on the first can also be found (Sea mammals The reference dataset has been validated holds an archive of several collections half year of data recovery of the first profiles from MEOP, XBT datasets simultaneously by both teams. An of original historical world-wide weather part of some 589 climatological stations from cruises…). (EN4 also takes data exhaustive comparison of the validation records from land stations and ships. spread throughout the Congo Basin from the ASBO dataset to supplement test results is now performed to find the The archive originates from the Deutsche (http://cobecore.org/map/). We discuss observations in the Arctic). best features of both datasets. Seewarte (German Marine Observatory), progress made in the automation of First advantage of this new merge The study shows the differences which was the predecessor organisation data recovery and issues regarding product is to enhance the space and between the EN4 and CORA validation of DWD in Hamburg. The largest archive transcription and provide a short time coverage at global and european results. It highlights the complementarity is the collection of meteorological overview of preliminary data products. scales for the period covering 1950 between the EN4 and CORA higher logbooks from sailing ships and till a year before the current year. This order tests. The design of the CORA and steamers. It contains about 37,000 Comparison of CORA and product is updated once a year and T&S EN4 validation charts is discussed to individual journals with an estimated total EN4 in-situ datasets validation gridded fields are alos generated for the understand how a different approach on amount of 23 Million observations that methods, toward a better period 1990-year n-1. The enhancement the dataset scope can lead to differences start in 1829 and end in 1945. compared to the revious CORA product in data validation. The new validation The majority of the observations are quality merged dataset. will be presented. Despite the fact that chart of the Copernicus Marine Service from the period from 1853 to 1934. The the profiles distributed by both datasets dataset is presented. Author Szekely Tanguy digitization procedure for the journals are mostly the same, the quality control Affiliation CNRS includes the registration of metadata, procedures developed by the Met Office archiving of optical scans and manual Co-authors and Copernicus teams differ, sometimes Data Rescue of Historic transcription of the observations. The R.Killick (Met Office), J.Gourrion (CNRS), leading to different quality control flags Observations from the Archives data are quality checked and transferred A.Piron (Altran), G. Reverdin (LOCEAN) for the same profile. of the German Marine into a data base. About 11 Million CORA and EN4 are both global delayed Started in 2016 a new study started Observatory observations are already stored in the time mode validated in-situ ocean that aims to compare both validation Author Axel Andersson data base. However, a large number of temperature and salinity datasets procedures to move towards a these observations have been digitized Affiliation Deutscher Wetterdienst distributed by the Met Office (http://www. Copernicus Marine Service dataset during previous decades and still have metoffice.gov.uk/) and Copernicus (www. with the best features of CORA and Co-authors to be assigned a respective metadata marine.copernicus.eu). A large part of the EN4 validation. A reference data set B. Tinz (DWD), L. Gates (DWD) record. Apart from ship observations, profiles distributed by CORA and EN4 composed of the full set of in-situ Historic observational data records are the Deutsche Seewarte also operated in recent years are Argo profiles from temperature and salinity measurements an important contribution for climate a world-wide net of overseas the ARGO DAC, but profiles are also collected by Coriolis during 2015 is used. reconstructions and analysis of past meteorological land stations, many of extracted from the World Ocean Database These measurements have been made weather events. Particularly in remote them situated at the coast or on islands. and TESAC profiles from GTSPP. thanks to wide range of instruments and data sparse regions, such as the The archive consists of more than 1500 (XBTs, CTDs, Argo floats, Instrumented In the case of CORA, data coming from open ocean, newly rescued data can stations, mostly from the periods from sea mammals,…), covering the global the EUROGOOS Regional operationnal significantly improve the knowledge 1884 to 1943. Nearly 200 stations have ocean. oserving system (ROOS) operated by about weather and climatic conditions already been digitized with a digitization European institutes no managed by in earlier decades and centuries. procedure similar to that of the ship National Data Centres and other datasets Deutscher Wetterdienst (DWD, German observations. Digitization of the data of profiles povided by scientific sources Meteorological Service) in Hamburg
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 57 Section 2 from China, Korea, the tropical Pacific, For example, quality control, Since about 15 years, the EUMETSAT Cameroon and Togo and Canada has transmission interruptions, and station EUMETSAF’s Climate Monitoring Satellite Application Facility on Climate been completed. The presentation will outages can occasionally affect data SAF: A sustained provision of Monitoring (CM SAF, www.cmsaf.eu) show the recent progress of the digitization availability. While orbital paths can be Climate Data Records for develops capabilities for a sustained efforts and ongoing analysis of the data. known, drift in certain instruments and Evaluation and Climate generation and provision of Climate Data the large number of available instruments Records (CDRs) derived from operational An important activity is the further makes it challenging to know which Monitoring meteorological satellites, which will be development of automatic quality control satellite is observing any region at any continued in the current phase until 2022. procedures, where the main task is to Author Rainer Hollmann point in the diurnal cycle. The ultimate aim is to make the resulting adapt the modern QC limits to the lower Affiliation Deutscher Wetterdienst data records suitable for the analysis of accuracy of the historical observations, Furthermore, there is information from Co-authors climate variability and the detection of different weather classifications, units the statistics generated by the data M. Schröder (Deutscher Wetterdienst), climate trends. and conventions. assimilation that can help understand the K. Fennig (Deutscher Wetterdienst), model and the quality of the reanalysis. M. Stengel (Deutscher Wetterdienst), The product portfolio of the CM Typically, the assimilated observations SAF comprises long time series of Development of Gridded J. Trentmann (Deutscher Wetterdienst), and their innovations are in observation- P. Fuchs (Deutscher Wetterdienst) Essential Climate Variables (ECVs) Innovations and Observations space data formats and have not been related to the energy & water cycle as supplement to MERRA-2 made easily available to reanalysis users. In recent decades climate variability and defined by Global Climate Observing change have caused impacts on natural System (GCOS). Thus, users have Author Michael G. Bosilovich A test data set has been developed and human systems on all continents. access to many parameters of the to make the MERRA-2 assimilated Affiliation NASA GSFC GMAO Observations are needed to understand water and energy cycle based on observations available for rapid and Co-author and document these interactions of the operational satellite instruments, but general use, by simplifying the data A.M. da Silva (NASA GSFC GMAO) climate system. They are increasingly also to fundamental climate data format. The observations are binned to based on remote sensing from satellites records based on microwave imager Atmospheric reanalysis have become a grid similar as MERRA-2 and saved as which offer global scale and continuous measurements thoroughly inter- an important source of data for weather net CDF. This data collection includes the coverage. Only long term and consistent calibrated and homogenized to be and climate research, owing to the mean and number of observations in the observations of the earth system allow us suitable for assimilation and integration continuity of the data, but especially bin as well as its variance. to quantify impacts of climate variability into re-analyses efforts. The time series because of the multitude of observational The data will also include the innovations and change on the natural and human of the climate data records range from data included (radiosondes, commercial from the data assimilation, the forecast dimension. From this understanding 8 to more than 30 years with a global aircraft, retrieved data products and departure and the analysis increment, one can estimate and eventually predict coverage for data based on polar radiances). However, the presence of as well as bias correction (for satellite future states of the earth system and orbiting satellites, while those based on assimilated observations can vary based radiances). We refer to this proof-of- quantify its vulnerability and resilience geostationary satellite data cover the on numerous factors, and so it is difficult concept data as the MERRA-2 Gridded to continuing anthropogenic forcing. region of the METEOSAT diskntil 2022 or impossible for a researcher to say with Innovations and Observations (GIO). In In addition, these observations can be new editions of climate data records any degree of certainty how many and this paper, we present the data format used in the evaluation and assessment (CDR) will be published extending the what type of observations contributed to and its strengths and limitations with of reanalyses data records and climate time-range and the portfolio. In particular, the reanalysis data they are using at any some initial testing and validation of the models. new products related to the following give point in time or space. methodology. topics will be developed and provided
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 58 Section 2 during CDOP 3 global precipitation Our confidence in using these data sets evaluated data available at 20CRv2 and But, it is not very clear about SCV and its (ocean and land), regional land fluxes to reconstruct past climate variability its newer version (20CRv2c) for Calm Bay severe weather because of the absence (Meteosat domain), global high clouds. requires careful efforts to validate (Buchta Tikhaya) located in the Franz Josef of meteorological station and the sparse This presentation will highlight results them against observations, especially Land archipelago for the period 1930– of observing data. The research and the from the currently available CDRs and in the Arctic, where the network of 1940. This study investigated the quality of understanding on SCV and its torrential will present an overview of the upcoming meteorological stations is sparse. In this reanalyzed surface quantities, such as 2-m rain are seriously restricted. Based new editions of CDRs. paper we have compared different kinds air temperature, 2-m specific humidity and on the situation of scientific research of measured meteorological data with 10-m horizontal wind speed. Comparison and operational forecast for SCV, this reanalysis products. Early-instrumental of vertical temperature structure produced paper discusses the field experiment of Evaluation of reanalyses for the (1801–1920) atmospheric pressure data by two versions of 20CR at Calm Bay was SCV and its importance for short-term Arctic based on instrumental from land stations covering the entire high based on data taken from PANGAEA – weather forecast. And the intensive historical observations Arctic have been compared with data Data Publisher for Earth & Environmental observation scientific experiment of SCV (grids located nearest the historical sites) Science. This digital data library provides has been carried out in summer from Author Rajmund Przybylak taken from the 2nd version of the 20th a historical archive of radiosondes and 2010 to 2017. Affiliation Nicolaus Copernicus Century Reanalysis Project (20CRv2). tracked balloons on standard pressure The intensive observation data for SCV University, Department levels back to the 1920s. of Meteorology and Another of our evaluations used air activities and its weather processes Climatology temperature taken from 20CRv2 and has been obtained, and using the ERA20C reanalyses for the warm half- multi-source data from the surface, Co-authors Field experiment of Southwest year in the periods 1871–1910 and 1901– radiosonde, radar observation in daily P. Wyszy´nski (Nicolaus Copernicus China vortex and its applications 1910, respectively. Data covered the weather forecast operation, it has been University, Department of Meteorology in short-term weather forecast maritime part of the Svalbard archipelago effectively improved the forecast for SCV and Climatology), D. Klaus (Alfred (74–82°N, 6–30°E). The majority of Author Yueqing Li and its torrential rain. The basic feature Wegener Institute Helmholtz Centre the data were taken from a Norwegian and anomalous evolution of SCV have for Polar and Marine Research), Affiliation Institute of Plateau collection entitled Arctic Norwegian been deeply and refinedly analyzed in K. Dethloff (Alfred Wegener Institute Meteorology, China Logbook Data: 1867–1912 available at weather map, which further reveal the Helmholtz Centre for Polar and Marine Meteorological the Computational Information Systems structural feature, development process Research), A. Rinke (Alfred Wegener Administration, & Heavy Laboratory Research Data Archive and weather influence of SCV. Institute Helmholtz Centre for Polar Rain and Drought Flood (CISL RDA). Besides data downloaded and Marine Research), T. Strzyz˙ewski Disasters in Plateau and Furthermore, the radiosonde data from the CISL RDA, we also used air (Nicolaus Copernicus University, Basin Key Laboratory of assimilation, from the intensive observation temperature data digitized from logbooks Department of Meteorology Sichuan Province scientific experiment of SCV, obviously gathered by us as part of various data and Climatology) improves the operation ability of the recovery projects. In this research we The Southwest China vortex (SCV) is a numerical weather forecast in Southwest The development of atmospheric have compared air temperature data very important influence system for the China. In a word, it is necessary to reanalyses that assimilate only surface from observations made on ships and precipitation weather of China during reinforce the field experiment and expand data thereby allowing one to extend the available in logbooks. summer half year. And the torrential data application for the forecast of SCV period of the datasets back to the mid rain of SCV is also a much complex and Analysis was conducted for four regions and its torrential rain. 19th and early 20th century is one of distinctive torrential rain in China. SCV and (grid boxes, 4° latitude × 12° longitude) the most significant advances in climate its torrential rain are always a key scientific NW, NE, SW and SE. Finally, we sciences. problem in weather research and forecast.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 59 Section 2
We adopted a Bayesian approach, since bias adjustment scheme from radiosonde Generation of high resolution the data at the observation locations temperature to radiosonde humidity Gridded, high-resolution precipitation conditional on are honored and the spatial covariance measurements. observational data sets for structure of the spatial process is rainfall observations and infrared We use for example ERA-Interim to Southeast Asia and South reproduced in each realisation. This brightness temperature detect such breakpoints and to adjust the America generates more realistic fields than time series to a globally more consistent Author Ieda Pscheidt some interpolation method. In a second Author Gerard van der Schrier data set. We apply two methods, one step, realisations of occurrence/non- Affiliation University of Bonn, adjusts the mean between breakpoints Affiliation Royal Netherlands occurrence of precipitation exceeding Meteorological Institute whereas the other adjusts the quantiles Meteorological Institute the same thresholds are obtained given Co-authors and thus the distribution of humidity. (KNMI) the simulated latent process. HIRAIN Petra Friederichs (University of Bonn, Co-authors is extended to several thresholds of For long-term trend estimates (1979- Meteorological Institute), Dan Cooley E.J.M. van den Besselaar (KNMI), precipitation amount. A final precipitation 2016) of mean humidity both methods (Colorado State University, Department R. Cornes (KNMI, CRU), A. Suwondo product with hourly temporal and 4 km work well. For low and high percentiles, of Statistics), Jennifer Hoeting (Colorado (BMKG), Iqbal (BMKG), A.M.G. Klein spatial resolution is generated from the however, the distribution matching State University, Department of Statistics) Tank (KNMI) fields occurrence/non-occurrence of the methods works better. We compare This study is part of a high resolution individual thresholds. our results with ERA-Interim and Validation for reanalyses datasets reanalysis project proposed for Germany demonstrate existing humidity biases in requires access to high-quality andhigh- and Europe (Bollmeyer et. al., 2014). ERA-Interim. resolution observational datasets. For The reanalysis for Germany assimilates Global bias-adjusted radiosonde Europe, the gridded dailytemperature On a preliminary basis we compare precipitation among other variables. For humidity and precipitation fields of the E-OBS radiosonde humidity measurements periods after 2007 radar data is used for dataset, based onthe meteorological Author Michael Blaschek also with brightness temperatures from this purpose. However, for earlier periods station data provided by the European microwave sounders (SSM/T-2, SSMIS). when radar data is not available another Affiliation University of Vienna NationalMeteorological Services (NMSs) Results indicate still large discrepancies high resolution precipitation dataset is Co-author to ECA&D (www.ecad.eu), has been between brightness temperatures required. L. Haimberger (University of Vienna) usedfrequently for these purposes. Using calculated from radiosondes and ERA- a similar approach, the SoutheastAsian To meet this need we propose the method Radiosonde humidity measurements Interim employing RTTOVv11 compared Climate Assessment & Dataset (SACA&D) HIRAIN to generate an ensemble of are valuable because of their long-term to measured brightness temperatures has been developed in a collaboration probable space-time precipitation fields availability and secondly because of high from microwave sounders. with NMSs from the region. given a dataset of rainfall observed by vertical resolution of the measurements. synoptic stations and infrared brightness Nevertheless, no measurement system is Based on the meteorological station temperature from Meteosat Second without uncertainties and for radiosondes data, a gridded dataset providing daily Generation. HIRAIN works in two steps. the changes in the observation system maps of temperature and precipitation lead to more or less clear breakpoints has been developed. This data set, SA- First, a Bayesian statistical model in the observed long-term time series. OBS, is introduced in this presentation. conditional on the observational data These artificial jumps and biases need to The spatial resolution of these maps are simulates the latent spatial Gaussian be removed and we adapt a well-known 0.25 x 0.25 degree, and data spans the process that drives the occurrence of precipitation exceeding a selected threshold.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 60 Section 2 period from 1981onwards. The gridding New or improved data sources cover Decisions in the SOT have direct impacts description of the new features included techniques used for this data set are various time periods, from the late 18th on the Near-Real-Time product as well in R3.0 that further support and augment similar as for the European data set. Century all the way into the modern as other aspects of data collection and reanalysis studies. period. These sources include newly processing. Finally, we will also report The most recent developments are that The R3.0 data and metadata digitized historical observations from on progress towards establishment for South America, in collaboration with characteristics will be described in a collections such as the English East of ICOADS as a Centre for Marine- NMSs in the region and the Climatic companion presentation. By using new India Company and the German Maury Meteorological and Oceanographic Research Unit (University of East Anglia, IT infrastructure and IMMA1 format collections, and updated external Climate Data (CMOC), within the new UK), a similar gridded dataset will be enhancements, R3.0 now has new archives such as the Global Tropical WMO-IOC Marine Climate Data System developed of which first results will be ocean-based data parameters, observing Moored Buoy Array (GTMBA) and World (MCDS), which is anticipated to facilitate presented. system bias adjustments developed and Ocean Database (WOD). further longer-term improvements provided by experts whose contributions in the effective management and A major observational format update create improved climate records, and stewardship of marine and near-surface ICOADS Release 3.0: Data is an extension to include near-surface assimilation model feedback from oceanographic data internationally. Characteristics and Future oceanographic data elements such reanalysis efforts. Priorities as salinity, nutrients and carbon cycle Unique report-level identifiers link parameters. These parameters, with Author Eric Freeman ICOADS Release 3.0: New all of these components together to associated depths, have been populated Relevance and Support for support traceability back to individual Affiliation NOAA/NCEI/ERT, Inc. from the WOD and other near-surface Reanalyses core records and further strengthen Co-authors oceanographic sources. The new the data provenance. Details about the A. Anderson (DWD), W. Angel (NOAA/ inclusion of a unique identifier (UID) to Author Thomas Cram content in these components as well as NCEI), P. Brohan (Met Office), L. Gates each individual marine report will help Affiliation National Center for their current status will be described to (DWD), E.C. Kent (NOC), S. Smith (FSU), to improve traceability and facilitate Atmospheric Research illustrate the new data that are available. S. Worley (NCAR) collaboration between ICOADS users. (NCAR) Furthermore, the community is invited to The latest update of the International Future plans for ICOADS will be Co-author contribute additional observing system Comprehensive Ocean-Atmosphere described in the second part of S. Worley (NCAR) adjustments and reanalyses feedback Data Set (ICOADS), Release 3.0 (R3.0), the presentation. The longstanding which then can be included as subsidiary The International Comprehensive provides major coverage expansions on MARCDAT/CLIMAR user community records linked to the core R3.0 records. Ocean-Atmosphere Data Set (ICOADS) the previous version (R2.5) for 1662-2014, will continue to actively help shape the Release 3.0 (R3.0) brings into operational The process and procedure to do so followed by improved monthly near- database and improve data management production new technical features and will be outlined. Uniquely, ICOADS as real-time (NRT) extensions, e.g. partly to meet future needs and continue to user-driven innovations that make it a foundational observation dataset is addressing the impacts of many masked make ICOADS a valuable resource for more data rich as both an input for and one of the first, if not the first, open Global Telecommunication System global climate research well into the output from reanalysis products. This access archive to capture significant (GTS) ship callsigns since late 2007. This future. The SOT is also a highly valuable presentation will highlight the suite of components of the data life cycle. In this presentation will describe the data and and integral source of feedback and product types and data access methods case, the ICOADS data life cycle includes metadata characteristics of R3.0, and collaboration to ICOADS in keeping the available from NCEI, NOAA ESRL/ routine new releases that add new data provide details on new data sources dataset in tune with current observational PSD, and NCAR, followed by a detailed sources and coverage throughout the full and on extensive observational format procedures and instrumentation, as well updates. as new sources of marine climate data.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 61 Section 2 period of record (over 300 years), and is assimilate a wide range of satellite data tool for the reanalysis production, itself. data exchange in the context of the furthermore updated with modern data (radiances, atmospheric motion vectors, The web interface provides a quick WMO Marine Climatological Summaries on a monthly basis. scatterometer winds and ground-based tree-based overview on the complete Scheme (MCSS). GPS measurements). observing system on one single page. This is supported by preservation in a Several data streams are combined into long-term archive that freely distributes The spread in the ensemble can be Instruments or satellites can be selected a consolidated archive with a constantly the data and related products and taken as a measure of the uncertainty and time series of statistics on their increasing data amount. Real-time GTS enables numerous flexible pathways in the reanalysis. It is to be hoped that usage can be plotted instantly from a data from ship, buoys and other marine to access the data. Finally, as will be improvements in the observation network previously created catalogue without the measurement platforms are automatically described in this presentation, an over time lead to more reliable analyses need of costly data retrievals. Besides stored in an interim database and are operational system has been developed with smaller uncertainty. Here this this data discovery mode there is the consolidated in near real-time for the to receive information back from the hypothesis is tested by comparing the possibility to download data. The OFA archive. Secondly, Voluntary Observing data user community that captures ensemble spread for short periods run serves feedback data from the ERA- Ship (VOS) data, which is collected by the knowledge gained and makes it with and without satellite data. 20C, ERA-Interim and ERA5 reanalysis. the Global Collecting Centres (GCC), is shareable with the next generation of An overview will be presented as well injected in delayed mode into the archive. users. as a real test case to demonstrate the In this context, DWD acts together with Introduction to the Copernicus’s importance of feedback data. UK MetOffice as a contributing as well as observation feedback archive a responsible member. In a third stream, Impact of satellite data on Author Gionata Biavati newly digitized data from the historic reanalysis uncertainty for Observational Data from the ship journal archive of the DWD are ECMWF UERRA Affiliation Marine Data Climate Centre continually added to the archive as well Co-author of Deutscher Wetterdienst as other available sources. All incoming Author Amy M. Doherty H. Hersbach (ECMWF) data sets are routinely checked with a Affiliation Met Office Author Axel Andersson Within the Copernicus Climate Change sophisticated high quality control (HQC) Affiliation Deutscher Wetterdienst Co-authors Service (C3S), one task is the provision procedure that performs several formal R. Renshaw (Met Office, P. Jermey of easy access to observations that were Co-authors and meteorological checks on the data. (Met Office), J. Davie (Met Office), L. Gates (DWD), H. Otten-Balaccanu ingested in global reanalysis as produced As part of the contributing member S. Mahmood (Met Office) (DWD), M. Schulz (DWD) at ECMWF. Key feature is the inclusion role in the GCC, German VOS data UERRA (Uncertainties in Ensembles of feedback information on how such The Marine Data Climate Centre of undergoes an additional manual quality of Regional ReAnalyses) is an EU- observations were used, like how well Deutscher Wetterdienst maintains an control. In the light of the evolution of funded project that provides high- they fitted the analysis products before extensive climatological archive of the WMO MCSS into the new Marine resolution reanalyses over Europe, and after assimilation,and estimates on quality controlled marine surface and Climate Data System (MCDS) new forms together with measures of uncertainty biases and data quality. atmospheric observations. Apart from of data management are implemented, in those reanalyses. As a part of This service will be provided by the web- recent data, the archive consists of a such as flexible data access and product UERRA, the Met Office is running based Observation Feedback Archive large amount of historic data ranging generation. Standardized data formats a single high-resolution reanalysis (OFA) as an integral part of the Climate back to the mid-19th century. Data and metadata handling is essential and a lower-resolution ensemble of Data Store (CDS) toolbox,with the aim is from the archive is used in a variety to allow data exchange with external reanalyses. These reanalyses cover to reach a wide range of reanalysis users. of application, such as operational partners, e.g. ICOADS. the satellite era (1979-present). They In addition it forms a relevant monitoring climate monitoring and international
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 62 Section 2
The presentation will give an overview compilation and quality control, and error Meteorological Information Center, quality control (QC) using NCEP GDAS of the marine data management at assessment. Such efforts took place CMA), Kaixi Hu (National Meteorological QC procedures, a “PrepBUFR” to the DWD that includes all stages from data within the ERA-CLIM2 project, aiming Information Center, CMA), Zhe Chen so-called NCEP DUMP BUFR conversion collection by the port meteorological at providing a better observational basis (National Meteorological Information tool were developed based on the python officer to data quality assurance and for reanalyses. The work on observations Center, CMA), Hui Jiang (National interface to NCEP BUFR library, and all aggregating into marine data products. ideally is one cycle ahead of the Meteorological Information Center, CMA), the merged conventional observations Current developments such as new generation cycle of reanalyses, allowing Chenghu Sun (National Meteorological were converted to DUMP format which routines for automatic and manual them to make full use of it. Information Center, CMA), Qi Zhao is needed by GDAS QC procedure. HQC, migration of the data archive to a (National Meteorological Information The presentation will also introduce In this paper we describe the activities high performance data base system to Center, CMA) the collection and processing of AMV within ERA-CLIM2, which range form facilitate user access will be highlighted and GPS-RO. As a pilot experiment, upper-air data rescue to satellite data CMA started global reanalysis efforts at as well as present and planned data the prepared observations will firstly recalibration and from the generation of the end of 2013 to produce CMA 40- products for a variety of applications. being assimilated in a GFS/GSI-3DVar snow cover products to the development year atmospheric reanalysis (CRA-40) based interim reanalysis (CRA-Interim) of a global station data metadatabase. The extending back to 1979. As observations covering 10-years from 2007 to 2016. data generated feed into global repositories assimilated in the NCEP climate forecast Observations for Reanalyses We also intend to present some initial and serve future reanalysis projects. system reanalysis (CFSR) covering – Lessons from ERA-CLIM2 results of observation minus analysis and from 1979 to 2014 and in the NCEP background from this pilot experiment. Author Stefan Brönnimann operational global data assimilation Affiliation University of Bern Observations Processing for system (GDAS) archive from 2014 to CMA 40-year atmospheric Co-authors present were collected, the basic idea On the Use of Sea Level Climate ERA-CLIM2 WP3 team reanalysis (CRA-40) for CRA-40 observations preparation is Data Record (CDR) for that, 1) use satellite radiances in CFSR/ Author Lipeng Jiang Reanalyses Evaluation Global dynamical reanalyes of the GDAS observation database directly; atmosphere and ocean fundamentally Affiliation National Meteorological 2) add more Chinese observations to Author Jean-Francois Legeais rely on observations, not just for the Information Center, CMA CFSR/GDAS database for conventional Affiliation CLS assimilation (i.e. for the definition of the Co-authors observations; 3) try to use the latest Co-authors state of the Earth-system components), Zhiquan Liu (NCAR), Chunxiang Shi reprocessed AMV and GPS-RO Y. Faugère (CLS), G. Taburet (CLS), but also in many other steps along the (National Meteorological Information observations from various organisations. MI. Pujol (CLS), G. Larnicol (CLS), production chain. Observations are Center, CMA), Zijiang Zhou (National At this point, the presentation will focus B. Meyssignac (LEGOS) used to constrain the model boundary Meteorological Information Center, CMA), on the processing of conventional conditions, for the calibration of Tao Zhang (National Meteorological Sea level is a very sensitive index of observations, AMV and GPS-RO. transfer function or retirevals, for error Information Center, CMA), Jie Liao climate change and variability. Sea level Chinese radiosonde, SYNOP, Ship/Bouy determination of observations, and for (National Meteorological Information integrates the ocean warming, mountain observations and aircraft observations the evaluation of data products. Center, CMA), Zhisen Zhang (National glaciers and ice sheet melting. Accurate collected from various data sources Meteorological Information Center, CMA), monitoring of the sea level is required This requires major efforts on the side were firstly converted to “PrepBUFR” Minyan Wang (National Meteorological to better understand its variability and of observations, including data rescue format (same as CFSR observations) Information Center, CMA), Shuang Yao changes as well as the exchanges (for historical observations), data and then merged to CFSR/GDAS (National Meteorological Information between ocean, land, cryosphere, and management (including metadatabases), database. In order to perform online Center, CMA), Lijuan Cao (National atmosphere. The satellite altimeter
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 63 Section 2 sea level has been measured by presented. Then, the characteristics and In order to achieve this goal their inputs, different successive missions since limits of the different products described observations, must be accurate, stable, Quantifying The Improvement 1993. More than 70 cumulated years above (C3S, CMEMS) will be presented and available over long time periods. In Reanalysis Accuracy Due of measurements have now been in order to help the ocean and climate Serving this need, the Fidelity and To Hobbyist Weather Stations reprocessed with the DUACS (Data community on their optimal use for uncertainty in climate data records Unification and Altimeter Combination validation, assimilation activities as well from Earth Observations (FIDUCEO) Author Khaled Sharif System) production system. as scientific studies. project reassesses satellite observations Affiliation ArabiaWeather Inc of different instruments, in terms of In addition of the altimeter instrument, Co-author determine the uncertainty, recalibrating the sea level estimation strongly relies M. Mansour (ArabiaWeather) Preparing HIRS radiances as the measurements, and increasing the on other complex systems such as orbit input to Reanalysis within the accuracy. ArabiaWeather has, over time, created solutions, reference fields and oceanic/ Copernicus Climate Change a large network of hobbyist weather atmospheric geophysical corrections. Within the presented study, we Service stations distributed to volunteers around During the past 6 years (2011-2017), the demonstrate an undertaking of preparing the Middle East and North Africa region, ESA Sea Level Climate Change Initiative Author Timo Hanschmann input satellite data for reanalysis in in an effort to cover areas that are has been the opportunity to improve the a research-to-operations mode. A Affiliation EUMETSAT too distant from traditional sources homogeneity and stability of the altimeter Fundamental Climate Data Record of observational data. sea level record. Co-authors (FCDR) of the High Resolution Infrared G. Holl (University of Reading, reading, Radiation Sounder (HIRS) is prepared, Due to the sparsity of existing weather Today, the altimeter sea level is used UK), V. John (EUMETSAT, Darmstadt, based on the latest science including stations, the region makes for a good for two main kinds of applications: (i) Germany), R. Roebeling (EUMETSAT, metrological principles. This means case study regarding the improvement in The retrieval of mesoscale signals in the Darmstadt, Germany), J. Schulz not only revising the calibration and reanalysis accuracy gained by increasing context of ocean modeling and analysis (EUMETSAT, Darmstadt, Germany) investigating inter-satellite biases, but the number of weather stations at the of the ocean circulation at global or also determining all the associated surface level. In this paper, we attempt to regional scale. This requires the most Availability of operational satellite uncertainties. quantify the accuracy improvement versus accurate sea level estimation at each observations on a multi decadal time scale leads to an increased use of the amount of weather stations added, time step with the best spatial sampling In this presentation, the focus is put on and also quantify the plateau effect that of the ocean. Such dataset is produced them in reanalysis and climate studies, the very first instruments that have been e.g., for the investigation of climate occurs once we reach a saturating point within the Copernicus Marine Service rarely investigated until now. The time in terms of stations added. (CMEMS) (previously distributed by trends and feedbacks. However, to series of HIRS on board of NIMBUS-6, AVISO). (ii) The monitoring of the long- detect and evaluate climate trends and TIROS-N, NOAA-6, and NOAA-8 is We also attempt to geospatially visualize term evolution of the sea level for climate feedbacks, the time series need to have analysed and their stability and variability this increase in weather station density applications and the analysis of Ocean/ a high temporal consistency, accuracy is presented and compared to those of versus accuracy improvement, and Climate Index (such as the global and (small bias), and precision (high signal the new and more stable instruments, quantify the relationships between regional Mean Sea Level evolution). to noise ratio). One objective of the such as on METOP-A and METOP-B. distance, density, and accuracy. Finally, Copernicus Climate Change Service Further, C3S builds on the experience we propose a method to optimally This requires a homogeneous and (C3S) is to provide improved global and and achievements of FIDUCEO. Thus, choose locations for future weather stable sea level record. Such dataset is regional reanalysis data that meet these this presentation will show results of stations in such a way that would produced within the Copernicus Climate requirements. FIDUCEO on the increased accuracy of maximize gained accuracy improvement. Service (C3S). The main steps of the HIRS radiances due to revised calibration altimeter production system will be and in depth uncertainty analysis.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 64 Section 2
applied to the imagers’ infrared and The recalibrated radiances are used to Re-calibration of Infrared and water vapour channels (at ~11 μm and derive products such as clear and all sky Recovering (eco-)climatological Water Vapor channels of imagers ~6 μm, respectively) on both EUMETSAT radiances as well as Atmospheric Motion data from Belgian colonial on EUMETSAT and JMA and JMA geostationary satellites, i.e., Vectors that can be assimilated into archives geostationary meteorological VISSR/JAMI/IMAGER on the GMS/ models used for reanalysis. In addition, MTSAT series and MVIRI/SEVIRI on the the data are also used to derive Global Author Innocent Banzi satellites METEOSAT series. Data from the Infrared Climate Observing System Essential Ngulu-kulu Author Viju John Atmospheric Sounding Interferometer Climate variables such as sea and land Affiliation Ghent University Affiliation EUMETSAT (IASI), Atmospheric Infrared Sounder surface temperature, cloud properties, Co-authors (AIRS) and High Resolution Infrared upper trophospheric humidity etc. Co-authors Kim Jacobsen (Xylarium, Royal Museum Radiation Sounder (HIRS/2) were used as for Central Africa), Tom de Mil (Xylarium, T. Tabata (JMA), R. Roebeling references for recalibration. (EUMETSAT), F. Ruethrich (EUMETSAT), Recent developments in the Royal Museum for Central Africa), Jan T. Hewison (EUMETSAT), J. Schulz The referencing was performed at the European Climate Assessment Van den Bulcke (Laboratory of Wood Technology), Hans Verbeeck (CAVElab, (EUMETSAT) HIRS/2 channel’s spectral response that & Dataset shows the best fit to the instruments in Ghent University), Koen Hufkens Geostationary meteorological satellites geostationary orbit. To keep the time Author Gerard van der Schrier (Richardson Lab, Harvard University) have been observing the Earth for series of reference measurements the more than 40 years to support weather Affiliation Royal Netherlands The COBECORE project (http:// same, AIRS and IASI spectra were Meteorological Institute cobecore.org) aims to establish baseline nowcasting and forecasting and other convoluted using the HIRS/2 spectral Co-authors climatological measurements by environmental applications. Due to their response, which revealed very small E. van den Besselaar (KNMI), valorizing climatological legacy data, long observation period, good temporal uncertainties as compared to directly C. Photiadou (KNMI), A. Squintu (KNMI), crucial for reanalysis. This lack of long- sampling and spatial coverage, these using hyper-spectral sounder spectra R. Cornes (KNMI, CRU), A. Klein Tank term (historical) climatological data observations could be of tremendous convoluted with the spectral response value for climate studies, such as on (KNMI), G. Verver (KNMI) leaves the central Congo Basin spatially from the geostationary instruments. and temporally under-represented. cloud properties and their impact on the Collocated geostationary counts and the The European Climate Assessment global radiation budget. Even today, the central Congo Basin is reference radiances are then regressed & Dataset aims to provide daily currently represented by only a few rain They are also shown valuable for to derive re-calibration coefficients for meteorological station-baseddata and gauges, limiting climate both retrospective assimilating into Numerical Weather each geostationary instrument. analysis for scientific research in and analysis and forecasts across the Congo outside the climate sciences. An important Prediction models used for generating This research contributes to the WMO Basin. Here we present the historical contribution to this activity is the E-OBS, reanalysis products. Climate applications initiative Sustained and Coordinated context in which measurements were with is the gridded data set with daily require high accuracy satellite Processing of Environmental Satellite made by La régie des plantations de la maps of temperature,precipitation and observations or at least a quantification data for Climate Monitoring (SCOPE- colonie (REPCO) and the Institut National pressure for Europe, based on ECA&D. and correction of effects due to changes CM) project No. 6: Inter-calibration of d’Etudes Agronomique du Congo In this presentation the latest changes to in the characteristics of satellites imager observations from time-series Belge (INEAC), covering six decades the ECA&D station coverage and products and sensors that appear during their of geostationary satellites (IOGEO), (1901 – 1960). We discuss the rationale are shown. Emphasis will be on the newly operational lifetime. which aims at establishing spatially behind the establishment of various introduced Quality Control procedures and and temporally homogeneous radiance measurement stations, the protocols used This presentation addresses a common homogenization of daily temperature data re-calibration approach that has been data from all geostationary satellites. as well as instrumentation. Our analysis
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 65 Section 2 provides contextual information critical to records from the two sensors, located at the proper valorization and interpretation Revisiting the data record of different depths, were revisited with the The effective use of of data collected within the COBECORE High Resolution Sea Surface help of reanalysis products as a proxy for scatterometer winds in current project. Temperature drifting buoys: the sea-state. The differences between and future GMAO reanalysis possible implications for climate the two sensors can be reduced from 0.21 K RMS to 0.06 K RMS after retaining Author Mohar Chattopadhyay Reducing uncertainty by data monitoring only the situations that likely correspond Affiliation Sceince Systems and rescue Author Paul Poli to well-mixed SST. Accounting for Applications Inc./GMAO, Author Philip Brohan Affiliation Météo-France individual buoy biases, the differences NASA Goddard Space are further reduced to 0.02 K RMS. Flight Center Affiliation Met Office Hadley Centre Between 2012 and 2015, the EIG This would tend to suggest a strong Co-authors The Twentieth Century Reanalysis EUMETNET Operational Service relationship of the relevance of SST W. McCarty (GMAO, NASA Goddard (20CR) has demonstrated the power of for surface marine observations measurement with depth and sea-state, Space Flight Center, Greenbelt, MD, USA reanalysis as a tool for inferring long- (E-SURFMAR) and European partners and the importance of these factors Scatterometer-derived near-surface term climate variability and change. funded and deployed drifting buoys when using in situ SST data for climate ocean vector wind retrievals provide In particular, it is an effective user equipped to measure High Resolution monitoring. Another result concerns global measurements complementary of the limited historical observations Sea Surface Temperature. The HRSST potentially the temporal stability of to the sparse conventional observing record, adding value to the available referred to three major improvements buoy SST data. The HRSST buoys were system which primarily consists of ships observations. A key virtue of 20CR is as compared to standard practices at first calibrated individually in certified and buoys over water surfaces. The that it is an ensemble product, and the the time. First, the positioning accuracy laboratories. RapidScat instrument was flown on the distribution across the ensemble is an was increased, thanks to GPS instead International Space Station as a quick invaluable measure of uncertainty. of Argos. Second, the temperature Three buoys were recovered and the was transmitted and reported at higher temperature sensors were brought and low cost replacement of QuikScat Using the relative entropy of resolution, 0.01 K instead of 0.1 K. Third, back to a certified laboratory in 2016. and as a continuation of the NASA the ensemble with respect to a each buoy used an individually calibrated Comparing the initial laboratory results scatterometry data record. climatolological distribution shows temperature probe, instead of one picked with those of 2016, a temporal drift of A unique characteristic of RapidScat was clearly the time and space variation of from a batch calibration. about 0.01K/year is found for each of that it flew in a non-sun synchronous the reanalysis skill. The dominant factor the three buoys. These results from orbit at an inclination of 51.6 degrees. inthe analysis skill is the availability of Note the first two improvements (but so few buoys cannot be claimed to This orbit allowed for the collocation of nearby observations for assimilation – not the third) are now standard on most be significant. However, if confirmed, measurements with other scatterometers making new observations available by drifting buoys. In addition, some of these these results would have applications as well as an ability to sample diurnal systematic data rescue can generate buoys were also fitted with two digital on the use of in situ SST buoy data signals. In the Modern-Era Retrospective large improvements in 20CR. probes, one in the buoy hull around 17 as a reference, without any temporal cm depth, and another located around 45 analysis for Research and Applications, drift correction, for the calibration and Version 2 (MERRA-2) reanalysis, the cm depth (as part of a conductivity and validation of satellite data and to monitor temperature sensor). scatterometry record began with the climate. the ESA European Remote Sensing This configuration, with two accurate (ERS) scatterometer on 5 Aug 1991 sensors, offered near-optimal horizontal and continued through today with and temporal collocation. The data the EUMETSAT Metop Advanced
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 66 Section 2
Scatterometer (ASCAT). RapidScat, Surface in-situ observations are affected The dataset will be publicly available in after 2004. This study examines the however, was not used in the MERRA-2 by several problems, in particular by NetCDF format, with the exception of potential for extending the use of system as development had been inconsistencies in space and time in the a small fraction of the data (due to the limb-sounding observations at earlier completed prior to the beginning of its measurement procedures, and by the policy of data providers); nonetheless the times and into the future, so that future data record. In this presentation, the lack of information concerning these information derived from this fraction (e.g., reanalyses may be more applicable to RapidScat ocean vector winds will be procedures. Moreover, human errors for the homogeneity tests) will be public. the study of long-term ozone changes. compared to MERRA-2, both in terms of often contaminate the quality of the Historical data are available from NASA the analysis fields and in the context of data in different ways. The absence instruments: the Limb Infrared Monitor of its global observing system, to assess of an official global repository for Towards a Representation of the Stratosphere (LIMS: 1978-1979); the the viability of using the data in future meteorological observations means Vertically Resolved Ozone Upper Atmospheric Research Satellite reanalysis systems developed by the that often data undergo numerous Changes in Reanalyses (UARS: 1991-1995); Sounding of the Global Modeling and Assimilation Office modifications by different users and Atmosphere using Broadband Emission Author Steven Pawson (GMAO) at NASA Goddard Space Flight different versions of the same series can Radiometry (SABER: 2000-onwards). Center. be found even within the same collection, Affiliation NASA GSFC For the post EOS-MLS period, the joint with usually no information on the Co-authors NASA-NOAA Ozone Monitoring and modifications applied. K. Wargan (NASA GSFC), C. Keller Profiling Suite – Limb Profiler (OMPS-LP) The EUSTACE daily LSAT (NASA GSFC), W. McCarty (NASA GSFC), instrument was launched on the Suomi- Within EUSTACE public collections dataset: A collection of 36000+ L. Coy (NASA GSFC) NPP platform in 201x and is planned for (mainly GHCN-D, ISTI, and ECA&D) unique in-situ daily temperature future platforms. This study will examine of daily maximum and minimum The Solar Backscatter Ultraviolet two aspects of these data pertaining to series with inhomogeneities temperature observations, together with Radiometer (SBUV) instruments on NASA future reanalyses. First, the feasibility identified some additional dataset with restricted and NOAA spacecraft provide a long- of merging the EOS-MLS and OMPS- data policy, were merged. Duplicates term record of total-column ozone and Author Yuri Brugnara LP instruments to provide a long-term were removed by comparing the deep-layer partial columns since about University of Bern record that extends beyond the potential Affiliation observations in each individual year of 1980. These data have been carefully lifetime of EOS-MLS. Co-authors each series with the data of the stations processed to extract long-term trends S. Brönnimann (Oeschger Centre for located within a 200 km radius. and offer a valuable resource for ozone If feasible, this would allow for long- Climate Change Research, University monitoring. Studies assimilating limb- term monitoring of ozone recovery in a Moreover, an automatic quality control of Bern) sounding observations in the Goddard three-dimensional reanalysis context. algorithm was applied to all series. Earth Observing System (GEOS) data Second, the skill of the GEOS DAS in EUSTACE is a EU Horizon 2020 project We also carried out an homogeneity assimilation system (DAS) demonstrate ingesting historical data types will be whose goal is to produce daily estimates assessment, by using four different that vertical ozone gradients in the upper investigated. Because these do not of surface air temperature since 1850 breakpoint detection algorithms (three troposphere and lower stratosphere overlap with EOS-MLS, use will be made across the globe for the first time, by relative tests and one absolute test), (UTLS) are much better represented than of system statistics and evaluation using combining surface and satellite data and provide breakpoint locations for with the deep-layer SBUV observations. independent datasets. Impacts of using using novel statistical techniques. As each series. The final result is a quality- a complete ozone chemistry module will part of this, tens of thousands of in-situ controlled dataset of ca. 750 million This is exemplified by the use of retrieved also be considered. data series were collected from various unique observations over the period ozone from the EOS Microwave Limb providers. 1850-2015 that will be assimilated into Sounder (EOS-MLS) instrument in the other EUSTACE products. MERRA-2 reanalysis, for the period
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 67 product is validated by the comparisons in both reanalysis work and for EOFs allows the DA to respect the global Section 3 – Methods with independent observations and other operational forecasts. This is the first scale teleconnections in the climate for reanalyses reanalysis products such as SODA, time it is applied on HF radar data. system. Experiments subsampling ECCO, GODAS. modern day observations to emulate historical data distributions are used to An ocean reanalysis system Assimilation using large scale compare the performance of the EOF DA Assimilation of HF radar ocean Author Changxiang Yan EOF error covariances to a more standard DA using a shorter current data into NEMO-Nordic Affiliation Institute of Atmospheric Author Daniel J. Lea length scale Gaussian error covariance using 4D EnVar model. Physics, Chinese Affiliation Met Office Academy of Sciences Author Lars Axell Co-author The EOF DA method is shown to Co-authors Affiliation SMHI M.J. Martin (Met Office) work efficiently in a 1/4 degree global J. Zhu (Institute of Atmospheric configuration and does a good job of Physics, Chinese Academy of Sciences), Baroclinic eddies in the ocean are at In modern ocean data assimilation (DA) filling in the large data gaps. The system J. Xie (Institute of Atmospheric least one order of magnitude smaller than systems it is common to use relatively also allows a hybrid of the EOF and Physics, Chinese Academy of Sciences) their atmospheric counterpart, being of isotropic and small length scale error standard covariance models. This has the order of ten km rather than hundreds covariance structures. The Met Office the potential to allow us to formulate a An ocean reanalysis system is developed of km. One consequence of this is that FOAM system, for example, produces DA system which works well both in the based on the hybrid coordinate ocean ocean current magnitudes and directions a global 1/4 degree analysis using the historical and in the modern period. An model (HYCOM). The ensemble optimal are often difficult to forecast, unless an NEMOVAR variational DA system with initial assessment of the hybrid approach interpolation which estimates the observation network of extremely high Gaussian error covariances with two will be presented. background error covariance matrix density is used. In practice, for currents length scales: one shorter length scale, by the season-dependent ensemble this can be accomplished using coastally the first baroclinic Rossby radius, and composed of the long-term model based High-Frequency radars measuring one longer length scale of 400 km. Challenges in ERA5 data ouputs is used. For in-situ ocean the radial components of the sea surface assimilation state-of-the-art observations, the layer thickness, instead These error covariances perform well currents. with the modern ocean data distribution. system in the early satellite of temperature and salinity profiles, is period assimilated. This poster presents results from Such error covariance models are, assimilation experiments using an however, inadequate for DA in historical Author Cornel Soci For the HYCOM, the model bias lead ensemble-based variational data ocean and coupled reanalyses. Due Affiliation ECMWF to the inconsistency between the assimilation method, 4D EnVar. It is to the historically inhomogeneous assimilation of in-situ observations and shown that assimilation of HF radar distribution of ocean observations, using Co-authors the assimilation of altimetry observations. data greatly improves the surface these small scale error covariances leads H. Hersbach (ECMWF), A. Horanyi Therefore, a new mean dynamical currents in the model NEMO-Nordic to large areas of the ocean not being (ECMWF), C. Peubey (ECMWF), topography required by the altimetry in the Skagerrak, off the west coast of corrected and any analysis produced is D. Schepers (ECMWF), A. Simmons data assimilation is obtained by the Sweden. In it’s 3-D form, this assimilation not likely to be a globally realistic and (ECMWF) assimilation of Argo into the HYCOM. method has earlier been used at SMHI consistent one. ECMWF is currently producing the The reanalysis experiment is carried out for assimilation of SST, salinity and We present an enhancement to ERA5 atmospheric reanalysis under the in the Indian and Pacific oceans during temperature profiles as well as sea ice, NEMOVAR to use Empirical Orthogonal framework of the EU-funded Copernicus 1993-2015. The resultant reanalysis Function (EOF) error covariances. Using Climate Change Service (C3S). ERA5 will
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 68 Section 3 span the period from 1950 to near-real This presentation describes the system (2000-2014), based on a The Oceanography Division of the Naval time and will replace ERA-Interim. ERA5 practical solution of recomputing the variational data assimilation scheme. Research Laboratory has performed two employs a hybrid data assimilation system, climatological part of the background As a proof-of-concept in constraining ocean reanalyses, a 17-year (1999-2015) namely a 10-member ensemble4D-Var term suited for this period. Horizontal the global ocean heat budget for use in coupled ocean-sea ice reanalysis forced data assimilation (EDA), at 62km horizontal correlation length scale become longer a coarse resolution ocean reanalyses by NCEP CFS reanalysis fluxes and, in resolution which generates a flow- and vertical correlations broader. We and Earth system simulations, the conjunction with the Marine Meteorology dependent background error covariance also present results showing that in the methodology proves able to shape the Division, a 7-year (2009-2016) coupled matrix (hereafter the background term) 1980s, the quality control of the buoy global ocean heat content tendencies atmosphere-ocean-sea ice reanalysis. to be used in a deterministic 4D-Var data network in the southern hemisphere has according to the TOA estimates, without The reanalyses are built upon the current assimilation system at higher horizontal an important impact on improving the compromising the accuracy of the Global Ocean Forecast System using resolution (31km). reanalysis quality. reanalysis itself. the HYbrid Coordinate Ocean Model The background term is a combination Spurious variability and under- (over-) (HYCOM) and the Los Alamos Community of a climatological part and a flow- Constraining the global ocean estimation present in experiments with Ice CodE (CICE). The ocean model has dependent one. The climatological part heat content through the use in-situ (no) data assimilation disappear 41 layers and an equatorial resolution of the background term depends on the of CERES derived TOA Energy when EEI data are assimilated. Similarly, of 0.08° (8.8 km) on a tri-polar grid with observation density, geographical area the surface warming hiatus present the sea ice model on the same grid that and model resolution. The ERA5 data Imbalance estimates without EEI data is significantly mitigated, reduces to ~3.5 km at the North Pole. assimilation system utilises the ECMWF inducing ocean warming at depths below Author Andrea Storto Sea surface temperature (SST), sea Integrated Forecasting System that was 1500 m and slightly larger in the Southern Affiliation CMCC surface height (SSH) and temperature- the operational model version in 2016 Hemisphere, in qualitative accordance salinity profile data are assimilated into (though at lower resolution). Co-authors with many other recent studies. C. Yang (CNR-ISAC), S. Masina the ocean using the Navy Coupled This version has been optimized to (CMCC and INGV) Ocean Data Assimilation 3D Var system best use data provided by the current Coupled high-resolution ocean- (NCODA) every day. The SSH anomalies observing system. In particular, the Clouds and the Earth’s Radiant Energy are converted into synthetic profiles System (CERES) sensors onboard ice and ocean-atmosphere-ice climatological part of the background reanalyses at the Naval of temperature and salinity prior to term has been generated based on TERRA and AQUA Earth Observation assimilation. the recent data rich period. For the satellites in combination with other Research Laboratory Incremental analysis updating of early satellite period (1979/1980s) over space-borne sensors measure the Author James G. Richman geostrophically balanced increments the southern hemisphere, however, it reflected shortwave radiation and Affiliation Florida State University is performed over a 6-hour insertion appears challenging to obtain optimal outgoing longwave radiation at the top window. For the coupled atmosphere- reanalysis results. Although the EDA of the atmosphere (TOA). The TOA net Co-authors ocean-sea ice reanalysis, the same provides flow-dependent information, the radiation budget (also referred to as the E. J Metzger (Naval Research Laboratory, ocean-sea ice model configuration is required changes in the background term Earth’s energy imbalance, EEI) is stored Stennis Space Center, MS USA) used. However, the prescribed CFS due to the sparser observing system are in the oceans for the largest part. P. J. Hogan (Naval Research Laboratory, Stennis Space Center, MS USA) fluxes are replaced by coupling to the too large to be represented by errors of In this study, we propose a procedure O. M. Smedstat (QinetiQ-North America, NAVy Global Environmental Model the day alone. to assimilate global TOA radiation Stennis Space Center, MS USA) (NAVGEM) with 50 levels and T359 imbalance estimates from CERES in (37 km) horizontal resolution. a coarse-resolution ocean reanalysis
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 69 Section 3
The coupling is done hourly using CDA1 is applied to a coupled reanalysis COARE 4.0 bulk fluxes on the ocean Effect of assimilating sparse Evaluation of a Coupled experiment for the period from November exchange grid. Following the lead of weather observations in two Atmosphere-Ocean Data 2013 to December 2015. the Ocean Reanalysis Intercomparison different ensemble reanalyses Assimilation System Reanalysis Comparison of the reanalysis result with Project (ORA-IP), the monthly mean in JMA/MRI Japanese 55-year Reanalysis (JRA-55) upper ocean heat and salt content Author Philip Brohan indicates that the overestimation of the from the surface to 300 m, 700m and Affiliation Met Office Hadley Centre Author Chiaki Kobayashi sea surface latent heat flux found in 1500 m, the mixed layer depth, the Affiliation Meteorological Research JRA-55 disappears in the reanalysis of depth of the 20°C isotherm, the steric The Twentieth Century Reanalysis (20CR) Institute MRI-CDA1. The system also effectively sea surface height and the Atlantic and the CERA-20C coupled climate Co-authors suppresses the excess rainfall in the Meridional Overturning Circulation for reanalysis are both ensemble products Y. Fujii (Meteorological Research tropics in JRA-55, particularly in the the two NRL reanalyses and the Simple assimilating only surface observations. Institute), C. Kobayashi (Meteorological Intertropical Convergence Zone (ITCZ) Ocean Data Assimilation (SODA 3.3.1) They assimilate almost the same set of Research Institute), T. Ishibashi in the Pacific. eddy-permitting reanalysis have been atmospheric observations, but CERA uses (Meteorological Research Institute), compared on a global uniform 0.5° grid. more information from each observation, These improvements of MRI-CDA1 over Y. Takaya (Meteorological Research assimilating marine winds in addition to JRA-55 mostly stems from improvements The differences between the NRL Institute), Y. Takeuchi (Meteorological the surface pressures used by 20CR. of atmospheric physical schemes in the coupled and uncoupled ocean Research Institute) coupled model. We are also conducting reanalyses for the 7-year overlap period Comparison of the two ensembles, in JMA/MRI has developed a weakly- the uncoupled reanalysis using the MRI- are small. The differences in heat and a time and place where observations coupled Data Assimilation (DA) system, CDA1. In the reanalysis, observational salt content increase with increasing coverage is sparse, demonstrates MRI-CDA1, based on JMA’s operational SST data are given instead of passing integration depth and salt content the relationship between individual systems. MRI-CDA1 is composed of oceanic data from the ocean to the differences are largest in the Southern observations and analysis precision, the global atmosphere 4-Dimensional atmosphere in the coupled model. Ocean. The differences increase when and shows the effect of the different Variational (4D-Var) system for numerical either NRL reanalysis is compared to assimilation choices. Although the difference of the coupled weather predictions, NAPEX, the SODA. reanalysis from the uncoupled one global ocean 3-Dimensional Variational becomes much smaller than the In addition, large differences in the (3D-Var) system for seasonal predictions, difference from JRA-55, averaged error equatorial circulation are found MOVE-G2, and the coupled atmosphere- and root mean square error against an comparing SODA to either NRL ocean model for seasonal predictions, observation-based precipitation dataset reanalysis. In the Indian Ocean, the JMA/MRI-CGCM2. (CMAP) are still reduced in a large part Equatorial Counter Current extends to The coupled atmosphere-ocean model of the tropics and subtropics. We also far to the east and the subsurface flow in is adopted as the outer model of the found that the consideration of the ocean the thermocline is too weak in both NRL atmospheric 4D-Var routine, although the surface currents in the estimation of the reanalyses. uncoupled atmospheric model is used as momentum fluxes across the sea surface the inner model. The analysis increments in the coupled system affects oceanic of ocean temperature and salinity circulation and near-surface wind fields. estimated by oceanic 3D-Var routine are adopted to the outer (coupled) model while integrating for prediction. MRI-
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 70 Section 3
0.25°x0.25° latitude/longitude grid using The assimilated data are limited to the Evaluation of SST/SIC Boundary in-situ observations as well as satellite Is the regional reanalysis an observations with the systems operated Conditions for the Next observations. alternative to the dynamical for more than about 60 years such as the surface observations at the observatories Japanese Reanalysis: JRA-3Q Use of the latter high-resolution SST/ downscaling to reproduce the and the upper air observations with SIC is expected to improve quality of past meso-scale atmospheric Author Masashi Harada radiosondes, maintaining the long-term the reanalysis by better representing Affiliation Japan Meteorological fields? consistency of the analysis quality. This influences of oceanic eddies on Agency experiment covers August 2014. The atmosphere aloft and by improving the Author Shin Fukui regional reanalysis is compared with accuracy of radiative transfer calculations Affiliation Tohoku University Sea surface temperature (SST) and sea two types of dynamical downscalings: in satellite radiance data assimilation, ice concentration (SIC) are important Co-authors one with time-integration uninterrupted although MGDSST is not available before input data in a reanalysis since they Toshiki Iwasaki (Tohoku University), over long-term and the other with 1981 due to the lack of input satellite are used as lower boundary conditions Kazuo Saito (Meteorological Research time-integrations over short-term and data. In this study, we will present results (BCs) for the atmospheric model and Institute, Japan Agency for Marine- reinitializations without assimilation. data assimilation system. In the past of preliminary evaluation of SST/SIC from Earth Science and Technology), Hiromu two Japanese reanalysis projects, i.e., COBE-SST2 and MGDSST, focusing on Seko (Japan Agency for Marine-Earth The former type of dynamical JRA-25 (Onogi et al. 2007) and JRA-55 comparison with other widely used SST/ Science and Technology, Meteorological downscaling often fails to reproduce (Kobayashi et al. 2015), the used SST SIC products. Research Institute), Masaru Kunii (Japan synoptic-scale fields due to the internal variability. Assimilating only the and SIC BCs were derived from COBE- The topics to be presented include long- Meteorological Agency) conventional observations in addition to SST (Ishii et al. 2005), which is a global term trends and variabilities of global/ We investigate the potential of the the forcing from the lateral boundaries century-long objective analysis dataset regional SST and polar SIC, as well as regional reanalysis assimilating only successfully prevents the degradation, produced from only in-situ observations. spatial distribution of their climatology. the conventional observations as an which is more apparent in the lower In addition, we will also show results of In the next Japanese reanalysis JRA- alternative to the dynamical downscaling fields. The latter type of dynamical preliminary experiments using the current 3Q (Japanese Reanalysis for Three to reproduce the past 3-dimensional downscaling underestimates the version of JMA’s data assimilation system Quarters of a Century), we are currently high-resolution atmospheric fields for precipitation due to insufficient spin-up as a prototype for the JRA-3Q system planning to utilize two SST/SIC products the studies of the local responses to the accompanied by the reinitializations, to investigate the impacts of different by the Japan Meteorological Agency climate change and various meso-scale although it captures the synoptic patterns SST/SIC BCs on analyzed atmospheric (JMA): COBE-SST2 (Hirahara et al. extreme events. appropriately. 2014) for the period up to the 1980s and conditions. Based on these results, we will discuss an appropriate period to A preliminary experiment of regional The regional reanalysis, where the MGDSST (Kurihara et al. 2006) for the reanalysis is conducted with the NHM- period thereafter. COBE-SST2, which combine two SST/SIC BCs for JRA-3Q simulated fields in the previous cycles production. LETKF, which consists of the Japan are inherited as first-guess, reduces the is an improved version of COBE-SST, is Meteorological Agency’s non hydrostatic produced on a 1°x1° latitude/longitude underestimation of precipitation. The model and the local ensemble transform configurations of this system are also grid using basically in-situ observations Kalman filter, applying the one-way only, whereas MGDSST is produced on a discussed from the perspective on long- double nesting to JRA-55. The inner term regional reanalysis. and outer domains cover Japan and its surrounding area with a gird spacing of 5 km and the eastern part of the Asia with a gird spacing of 25 km, respectively.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 71 Section 3
The use of these meteorological (SMOS) approach combined with meta- Modeling process chain of reanalysis datasets may solve uncertainty Post-treatment of the Climate Gaussian spatio-temporal (MGST) ECMWF reanalysis data to of data. In addition, phenomena such as Forecast System Reanalysis random fields were used to this aim. rainfall evolution require the analysis of monitor rainfall evolution (CFSR) daily precipitations The SMOS approach used CFSR time series of ECMWF meteorological across the Great Lakes region precipitation as covariate and is Author Aimé Richard Hajalalaina reanalysis datasets and the development based on two regression models, the Affiliation Ecole de Management of automated and reusable processing (Canada) logistic regression to deal with rainfall et d’Innovation chains for monitoring rainfall evolution. Author Dikra Khedhaouiria occurrence and the vector generalized Technologique, University We propose to formalize these Affiliation INRS-ETE linear model in a Gamma distribution of Fianarantsoa processing chains from modeling an framework for the intensity. Two skill abstract and concrete models based Co-authors Co-authors scores (Brier and continuous ranked on existing standards in terms of A.M. Mailhot (Institut national de la Angelo Raherinirina (Ecole Normale probability skill scores) showed that interoperability (International Standard recherche scientifique, Centre Eau Supérieure, Université de Fianarantsoa, estimated SMOS distributions had Organisation ISO and OGC Open Terre Environnement), A.C.F. Favre Madagascar), Adolphe Ratiarison a better predictive power than the Geospatial Consortium). The use of these (Univ. Grenobles Alpes, CNRS, IRD, (Laboratoire de la Dynamique de climatology for both precipitation standards solves uncertainty of process. IGE, Grenoble INP) l’Atmosphère, du Climat et de l’Océan, occurrence and intensity. Université d’Antananarivo, Madagascar), These processing chains modeled The most important challenge that many Thérèse Libourel (Université de will be capitalized, and diffusible in countries faces, including Canada, is Post-treated daily rainfall fields were Montpellier, Montpellier, France) operational environments. Our modeling to characterize historical precipitation then generated from SMOS daily approach uses work-context concepts. considering the low station density distributions with the use of the MGST In this paper, we propose a models of These concepts need organisation of in many of their regions. Reanalysis, random fields to ensure persistence process chain and knowledge-based of human resources, data, and process generated by Numerical Weather and spatial consistency in the series. meteorological reanalysis datasets that in order to establish a knowledge- Prediction methods assimilating past Selected climate indicators (e.g., annual help scientists, working in the field of based connecting the two latter. This observations, are an attractive alternative cumulative wet day or spatial correlation) climate and in particular of the rainfall knowledge-based will be used to solve as they provide coherent, spatially and were estimated for post-treated, evolution, to solve uncertainty of spatial uncertainty of meteorological reanalysis temporally continuous meteorological observed and CFSR precipitation series. resources (data, process) to monitor datasets resources for monitoring rainfall fields for a specific period and domain. Comparisons between these indicators the rainfall evolution in an area. Indeed, evolution. However, reanalysis precipitations cannot helped identify the advantages of using rainfall evolution mobilizes all research, be directly used as local estimates post-treated CFSR instead of CFSR, and various methods of meteorological without post-treatments to correct bias highlighted which aspects of the daily reanalysis datasets processing are and other errors. post-treated sequences still need further proposed. The ECMWF (European Centre investigations. for Medium-Range Weather Forecasts) The main objective of this study was meteorological reanalysis datasets to post-treat the CFSR gridded daily available at present are voluminous and precipitation over the Great Lakes region heterogeneous in terms of spatial and in Canada to provide spatially-coherent temporal resolutions (ERA-15, ERA-40, local estimates of precipitation series ERA-Interim and ERA-20C reanalysis). at sites without historical records. The Stochastic Model Output Statistical
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 72 Section 3
air temperature, surface pressure, pressure, surface humidity, surface wind, to reduce the analysis error and water Progress of CMA Land Data surface humidity and surface wind surface shortwave radiation, and surface budget residuals. The assimilation results Assimilation System (CLDAS) forcing data; As for shortwave radiation precipitation. indicate that the analysis error is reduced forcing data, we develop a new method and the water imbalance is mitigated with Our assessment shows that indexes Author Chunxiang Shi based on DISORT method, rewrite code this approach. of CLDAS-V2.0 products are better Affiliation National Meteorological with parallel technology, use numerical than any other similar product in China. Information Center forecast product and reanalysis data It is encouraging that CLDAS-V2.0 to replace climatic background field; The application of variational Co-authors products has been used operationally in we also use three land surface models data assimilation method on 2D Zhiwei Jiang (National Meteorological monitoring and forecasting of regional (CLM3.5, CoLM and Noah-MP1-4) to gain tides model for Malacca Strait Information Center), Xiao Liang drought in Inner Mongolia, drought a more steady and accurate land surface (National Meteorological Information monitoring in Qinghai, and numerical Author Evie Hadrijantie Sudjono simulation using assemble method. Center), Tao Zhang (National prediction research in Beijing. A new (2) In high performance computing Affiliation Marine Geological Meteorological Information Center), land data assimilation system is under environment of China Meteorological Institute Lipeng Jiang (National Meteorological construction with the ability to assimilate Administration, we successfully develop Co-authors Information Center), Bin Xu (National soil moisture observations and satellite CLDAS-V2.0 operation system with Agus Setiawan (Marine Research Center, Meteorological Information Center), brightness temperature. We are looking the standard of China Integrated Ministry of Marine Affairs and Fisheries, Shuai Han (National Meteorological forward to build the best land data Meteorological Information Sharing Indonesia) Information Center), Zhi Zhu (National assimilation system in China System (CIMISS). Using EC-Flow Meteorological Information Center) A variational data assimilation method software, we build Land Surface Forcing was applied in this study in order to CMA Land Data Assimilation System Data Fusion Sub-system, Land Surface Soil Moisture Assimilation Based improve the result of 2D tides model of (CLDAS) is founded by Multi-source Data Assemble Simulation Sub-system, on a Modified ETKF Malacca Strait. Several available tidal Fusion Team in National Meteorological Product Service and Distribution Sub- measurement data were assimilated Information Center, China Meteorological system, Product Evaluation Sub-system, Author Guocan Wu Administration. In May 2017, second into the tides model by applying the and Product Monitor Sub-system. Affiliation Beijing Normal University version of CLDAS (CLDAS-V2.0) has conjugate gradient least square method. In the end, we build the first operational been put into operation In CLDAS-V2.0, Assimilating observations to a land By comparing the results of data land data assimilation system in China, we have three important progresses: surface model can further improve soil assimilation model with forward model as which has complete data acquisition, (1)Through import and digestion, we moisture estimation accuracy. However, well as independent data (measurement product production, product evaluation, realize key technologies of land surface assimilation results largely rely on data that were not used in the product monitoring, product archiving, multi-source data fusion and analysis, forecast error and generally cannot assimilation), some improvements were product distribution ability.(3) Based and transform these technologies from maintain a water budget balance. In this obtained. This method can significantly on comprehensive consideration of research to operation. study, shallow soil moisture observations reduce the over- and under-estimate feedback from different research and are assimilated into Common Land results obtained by forward model. Based on previous survey, we choose operation users, we widen spatial STMAS developed by Xie as our Model (CoLM) to estimate the soil coverage of our product and develop moisture in different layers. method to fuse numerical forecast more land surface products including product and observations from more soil moisture, soil temperature, surface A proposed forecast error inflation and than 50000 surface meteorological skin temperature, relative moisture of water balance constraint are adopted in observation stations to produce surface the soil, surface air temperature, surface the Ensemble Transform Kalman Filter
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 73 Section 3
By excluding the data during daytime, The representation of the diurnal atmospheric component with a local Toward Assimilation of AHI over sandy land, Tibetan Plateau, or to seasonal variability of the water ensemble transform Kalman filter Surface-sensitive Channels with steep terrains, the brightness cycle on small scales, needed for the (LETKF). temperature simulations generated representation of surface and sub- over Land – A Quantitative To assess the added value of using such by the Community Radiative Transfer surface water flow in river catchments, Assessment of Simulation a soil-vegetation-atmosphere-transfer- Model (CRTM) with the ECMWF LST and is not well represented by current model in ensemble mode, we evaluate Accuracy CAMEL_HSRemis database compare reanalyses. However, the interest in such precipitation and soil moisture with very well with the Advanced Himawari data sets is increasing for hydrological Author Xiaoyong Zhuge respect to independent measurements Imager (AHI) observations statistically and agricultural applications. Affiliation Nanjing University and compare them to existing high- and instantaneously. This study suggests Recent studies on land surface resolution atmospheric regional that the AHI surface-sensitive channels Simulations of surface-sensitive channels simulations for specific river basins, reanalyses as well as a pure dynamical over land could be effectively assimilated from geostationary imagers over land with a finer grid spacing and driven by downscaling experiment with the coupled and contribute to improved numerical require accurate land skin temperature global reanalyses, show a significant Te r r SysMP. weather predictions. (LST) and infrared land surface emissivity improvement in the representation of soil (LSE). Compared with ground-based moisture and precipitation. The next step observations, large biases are found in Ultra-high resolution reanalysis would be to allow a feedback between Using lagged covariances the European Center for Medium range the land surface and the atmosphere to assimilate RAPID data Weather Forecasting (ECMWF) LST for a river catchment to take place, in order to achieve a Author Christopher Thomas analyses during daytime, over sandy Author Clarissa Figura sustainable effect on the water cycle land and Tibetan Plateau, and areas Affiliation Department of Affiliation University of Bonn within the terrestrial system as a whole. Meteorology, University with terrain height differences between This study focuses on an ensemble of 0.25° and 1-min topography resolutions Co-authors of Reading A. Hense (Meteorologisches Institut retrospective analyses of a short summer outside the range from -100 to 200m. Co-authors der Rheinischen-Friedrich-Wilhelms period for a catchment in the western Keith Haines (Department of Meteorology, The Combined Advanced Spaceborne Universität Bonn), J. Keller (Hans- part of Germany. University of Reading), Irene Polo Thermal Emission and Reflection Ertel-Center for Weather Research, We utilize a limited area model setup (Department of Meteorology, University Radiometer (ASTER) and Moderate Deutscher Wetterdienst), C. Simmer at horizontal resolutions of 1 km for of Reading), Jon Robson (Department Resolution Imaging Spectroradiometer (Meteorologisches Institut der the atmosphere and 500 m for the of Meteorology, University of Reading) (MODIS) Emissivity over Land (CAMEL) Rheinischen-Friedrich-Wilhelms land surface and soil. The simulations High Spectral Resolution Emissivity Universität Bonn), I. Thiele-Eich are based on the Terrestrial Systems The motivation of this work is to database (CAMEL_HSRemis) have the (Meteorologisches Institut der Modeling Platform (TerrSysMP) which assimilate the observations of the AMOC highest accuracy than the International Rheinischen-Friedrich-Wilhelms has the capability to exchange the made by the RAPID array at 26°N in Geosphere-Biosphere Programme Universität Bonn), S. Wahl (Hans- relevant state vectors between the the Atlantic Ocean by modifying ocean (IGBP) emissivity and the University Ertel Center for Weather Research, soil, vegetation and the atmosphere in densities ‘upstream’ in the Labrador Sea. of Wisconsin at Madison (UW) High Meteorologisches Institut der either direction, thus representing a fully Previous studies have shown that the Spectral Resolution Emissivity (UW_ Rheinischen-Friedrich-Wilhelms coupled terrestrial model approach. AMOC is robustly sensitive to anomalies HSRemis) databases. Universität Bonn) in the Labrador Sea which occur at a In order to bring the model closer time lag of several years earlier. to observed precipitation, rain radar reflectivity is assimilated into the
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 74 Section 3
The RAPID data will be assimilated into between biased and nearby reference a high-resolution (0.25°) global NEMO- Variational bias correction of observations (which are assumed to be CICE model. Assimilating the data using Sea Surface Temperature unbiased). a standard variational procedure with observations First, the bias correction system was a multi-year time window would be tested using the Lorenz 63 model. Under impractical in such a model. Instead, Author Daniel J. Lea most parameter regimes the VarBC the aim is to use robust covariance Affiliation Met Office scheme with observations-of-bias information to make earlier increments Co-authors worked well. However, when the true without the need for an adjoint. J. While (Met Office), bias was very small VarBC methods were The covariances are used to assimilate M.J. Martin (Met Office) found to slightly degrade the analysis the lagged data on top of the trajectory Observations can contain significant relative to doing no bias correction. produced by an initial (standard) systematic error. With Sea Surface Under all circumstances the VarBC variational assimilation. Using earlier Temperature (SST) data from satellites, scheme including observations-of-bias assimilation increments should give biases arise due to both measurement outperformed a VarBC scheme without better continuity to the circulation and and processing error, with a major source these observations. the heat transports, making the model of bias coming from uncertainty in the Second, we show results from applying more useful for coupled forecasting. atmospheric state used in the retrieval. the VarBC scheme in a realistic setting We will present the lagged covariance If unaccounted for, SST observation using the NEMO ocean model and methodology and show results from biases will propagate through any data NEMOVAR data assimilation framework. simulation studies of an idealised system. assimilation procedure and contaminate The system is tested both for a period We will also show the results of the the analysis. We have developed a where reference data are plentiful, and assimilation of RAPID data. Variational Bias Correction scheme for a period with only sparse reference (VarBC) for estimating observation bias data. Real data from the AQUA- in satellite measured SST. In the VarBC AMSRE, NOAA-AVHRR and NOAA- system, observation bias is estimated by METOP instruments are bias corrected. appending the bias state to the control Reference data were taken from vector and modifying the observation drifting buoys and the ENVISAT-AATSR operator to remove the bias from the instrument. observations before comparing to the state. The system is compared to the output of the Met Office’s current offline bias 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 75 permitting model specifications. The In order to assess the quality of the Meteorological fields within the ensemble Section 4 – Evaluation analysis is conducted with respect to climate representation and thereby average include 2-meter air temperature, and intercomparisons the representation of near surface point the added value of regional data precipitation, and 500-hPa geopotential observations for precipitation and wind. sets, we also quantitatively verify the heights. The original reanalyses were of reanalyses indices derived from reanalyses with translated onto a common 0.5°x0.5° independent observations.decadal and latitude-longitude grid using bilinear Added value of regional Added value of regional multi-decadal timescales interpolation. In this paper, the merits reanalyses: Precipitation reanalyses: Representation of each reanalysis model are examined and wind of climate indices against the ensemble average for the 30- An Ensemble Average year climate period 1981–2010. Author Jan D. Keller Author Sabrina Wahl and Evaluation of the Third Affiliation Hans-Ertel-Centre for We find that the individual reanalysis Affiliation Hans Ertel Center for Generation Global Climate Weather Research models perform similarly, but the Weather Research Reanalysis ensemble better approximates the Co-authors Co-authors observed global average. The four- S. Wahl (Hans-Ertel-Centre for Weather Author Jeffrey D. Auger J.D. Keller (Hans Ertel Center for Weather member reanalysis ensemble can be Reserach, University of Bonn) Affiliation University of Maine Research, Climate Monitoring Branch) examined through the website Climate The importance of reanalyses as a Co-authors Reanalyzer (http://cci-reanalyzer.org). Regional reanalyses are a rapidly basis for numerous applications in S. D. Birkel (Climate Change Institute, emerging field of research. Such data geosciences, economics and other fields University of Maine), K. A. Maasch sets constitute a valuable source of has significantly grown over the last (Climate Change Institute, University An Ensemble Version of the Daily information on smaller spatial scales decade. Therefore, a comprehensive of Maine), P. A. Mayewski (Climate E-OBS Dataset compared to established global evaluation and intercomparison of Change Institute, University of Maine), reanalyses. As the production of regional Author Richard Cornes reanalysis data sets is essential. K. C. Schuenemann (Metropolitan State reanalyses requires a high computational KNMI Here, we quantify the added value of University of Denver) Affiliation effort, the quantification of the added regional atmospheric reanalyses (such Co-authors value compared to global reanalyses A global ensemble average of monthly as COSMO-REA6) compared to their Gerard van der Schrier (KNMI), and/or regional downscaling products output from the four latest-generation global forcing reanalysis products (e.g., Else van den Besselaar (KNMI), is of high interest. In this study we climate reanalysis models for the years ERA-Interim, MERRA-2) with respect to Phil Jones (CRU/UEA) investigate global and regional reanalyses 1979–2013 is presented here. The models monitoring climate and its variability. with different horizontal resolutions and used in this study are ECMWF Reanalysis Daily, gridded datasets formed solely model specifications with respect to their To this end, we investigate the Interim (ERA-I), NCEP Climate Forecast from station data provide an important near surface representation of wind and representation of climate indices in the System Reanalysis (CFSR), JMA 55-year tool for the evaluation of reanalysis precipitation. reanalyses in comparison to indices Reanalysis (JRA-55), and NASA Modern- datasets. However, uncertainty in the derived from observations. The set Era Retrospective Analysis for Research gridded datasets is rarely taken into Especially for the European domain, of climate indices in consideration and Applications (MERRA). Although each consideration in such comparisons, several regional reanalysis data sets comprises simple measures such as of these models is considered state-of- primarily because few gridded datasets are available. A comparison with number of summer days or frost days but the-art, an ensemble average can afford a provide estimates of uncertainty. In this independent observations allows for also aggregated indices, e.g., heating/ more statistically robust climate signal by study we describe a new version of a quantification of the added value of cooling degree days. smoothing model biases. the daily, Europe-wide E-OBS gridded higher resolutions and/or convection-
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 76 Section 4 temperature and rainfall dataset that these NMS datasets compared to the While MERRA-2 indicates that the valuable, but unique, details that can be contains a number of significant current operational version of the dataset Arctic Amplification has occurred, a used to understand the climate of and developments over earlier releases. (version 14.0). ten member ensemble of the MERRA-2 biases within the model itself.” Atmospheric Model Intercomparison Notably, uncertainty estimates are The new version of E-OBS is expected to Project (M2AMIP) simulations, using generated from a 100-member ensemble aid evaluation of global-scale reanalyses the same prescribed climate forcing, Annual and semiannual cycles of realizations of each daily gridded across Europe, but particularly including Sea Surface Temperature of midlatitude near-surface field. In order to produce a consistent European-scale regional reanalyses (SST) and ice, does not. An evaluation temperature and tropospheric ensemble of realizations, the original of the temperature tendency within the interpolation method used in E-OBS baroclinicity: reanalysis data lower troposphere due to radiation, has been overhauled. In contrast to An Intercomparison of Changes and AOGCM simulations moisture, and dynamics as well as the the kriging/spline method used in Associated With Earth’s Lower surface energy budget in MERRA-2 and Author Valerio Lembo earlier versions, we have made use Tropospheric Temperature Using M2AMIP will demonstrate that despite University of Hamburg of Generalized Additive Modelling. Affiliation Traditional and AMIP-style identical prescribed SSTs and sea ice in Topographic effects are integrated Co-authors Reanalyses bothversions, enhanced warming in the through the modelling of gridded I. Bordi (CINFAI), A Speranza (CINFAI) Arctic and a suppressed warming in the background fields that are calculated Author Allison B. Collow Mid-latitudes in MERRA-2 is in response Seasonal variability in near-surface air using month-by-month climatological Universities Space Affiliation to the analysis increment tendency due temperature and baroclinicity from the averages calculated over the period Research Association to temperature observations that correct ECMWF ERA-Interim (ERAI) reanalysis is 1961-90. Co-author for issues related to inconsistent SST and analysed in this study. This is compared In addition to altitude, these background M.G. Bosilovich (NASA GSFC) ice boundary conditions, as presented by with a set of six coupled atmosphere– ocean general circulation models fields also incorporate additional “Reanalyses have become an integral Cullather et al. environmental factors, such as coastal (AOGCMs) participating in the Coupled tool for evaluating regional and global Furthermore, the implications of the proximity and slope/aspect. To assess Model Intercomparison Project phase 3 climate variations, and even more about weaker equator-to-pole temperature the success of the new interpolation and 5 (CMIP3 and CMIP5). the climate and the reanalysis itself gradient in M2AMIP on the Mid-latitudes method, the gridded data are compared can be learned through comparison will be discussed through an analysis The annual and semiannual cycles against several high-resolution gridded to identical free-running simulations of variables representing the jetstream, of hemispherically averaged fields datasets produced by National following the guidelines of the storm tracks, and blocking. Theory are investigated using univariate and Meteorological Services (NMS) across Atmospheric Model Intercomparison suggests an enhanced equator-to-pole bivariate spectral analysis. The aim is Europe. Project (AMIP). temperature gradient will decrease to assess the agreement between ERAI and coupled models in the reproduction These datasets generally contain many Observations and numerous reanalyses, zonal flow in the Mid-latitudes, thereby of the near-surface temperature and more station data and are therefore including the Modern Era Retrospective increasing meridional flow and slowing baroclinicity annual and semiannual expected to replicate the true daily analysis for Research and Applications – the progression synoptic systems and cycles and their coherency and relative fields of temperature or precipitation Version 2 (MERRA-2), have demonstrated it will be demonstrated that this is not phase. Concerning univariate analysis, a more accurately than E-OBS, but do that the Arctic has warmed more rapidly necessarily the case in M2AMIP. statistically significant power spectrum so at a scale that is comparable to than anywhere else in the world, referred Analysis increments from reanalyses as peak is found at the annual frequency E-OBS. On the whole the new version to as “Arctic Amplification”, though well as a comparison to a free-running in the zonally averaged fields of both of E-OBS has reduced error relative to uncertainty still remains regarding how version of the model both provide hemispheres. this has impacted the Mid-latitudes.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 77 Section 4
The semiannual peak, instead, shows system of the region that is characterized less power and in the NH seems to Assessment of cloud geometry by strong coastal upwelling and one of Assessment of MERRA-2 Land have a more regional character, being in ERA-Interim and ERA-20C the driest regions on Earth land inwards, Surface Energy Flux Estimates observed in the North Pacific Ocean over the Southeast Pacific using i.e. the Atacama desert. region. Bivariate analysis for such Author Rolf H. Reichle satellite observations Within the German Science Foundation a region and the whole Southern Affiliation NASA/GSFC funded Collaborative Research Center Hemisphere midlatitudes shows some Author Christoph Böhm “Earth at its dry limit” our overarching Co-authors discrepancies between ERAI and Affiliation University of Cologne goal is to understand the moisture supply C. S. Draper (NASA/GSFC and NOAA model data, as well as among models, Co-authors to the Atacama desert and its variability ESRL/CIRES), R. D. Koster (NASA/GSFC) especially regarding the semiannual Susanne Crewell (Institute of Geophysics which is to a large degree affected by frequency. Specifically, (i) models and In NASA’s Modern-Era Retrospective and Meteorology, University of Cologne, stratocumulus clouds moving inland. ERAI agree on the coherency at the analysis for Research and Applications, Germany), Ulrich Löhnert (Institute of Reanalyses such as ERA-Interim and annual and semiannual frequency in version 2 (MERRA-2) reanalysis the Geophysics and Meteorology, University ERA-20C are well suited to study trends both hemispheres, and (ii) on the annual land is forced by replacing the model- of Cologne, Germany), Johannes Quaas and variability in cloud geometry with frequency, showing a relative phase of generated precipitation with observed (Institute for Meteorology, University of respect to interannual and interdecadal 220±15°. precipitation before it reaches the Leipzig, Germany), Odran Sourdeval patterns such as El Niño Southern surface. We assess the MERRA-2land The latter denotes an approximately (Institute for Meteorology, University Oscillation or Pacific Decadal Oscillation. surface energy fluxes and 2 m air 1-month phase shift between of Leipzig, Germany), Johannes In order to further assess the quality temperatures (T2m) and investigate temperatures and baroclinicity annual Mülmenstädt (Institute for Meteorology, of the reanalyses, a comparison to whether the inserted precipitation cycle. At the semiannual frequency University of Leipzig, Germany) satellite retrievals from Multi-angle observations result in the expected model phases show a wider dispersion The representation of clouds in Imaging SpectroRadiometer (MISR) improvements to these fields. Averaged in both hemispheres with larger errors climate models is still subject to large on Terra is carried out. In addition, over global land, MERRA-2 overestimates in the estimates, denoting increased uncertainties. In particular this holds to the more traditional parameters the latent heat (LH) and incoming uncertainty and some disagreement true for marine boundary layer clouds. cloud fraction and cloud top height a shortwave radiation (by 5-10 W/m2) among models and with ERAI. We As the Earth’s radiation budget is novel approach enables us to derive and underestimates (in magnitude) believe that better constraining the cyclic strongly influenced by clouds, these CBHs with a horizontal resolution of the incoming and outgoing longwave response of current global atmosphere– uncertainties introduce a wide spread 0.25°x0.25°. Previous research shows a radiation (by 10-15 W/m2), while the ocean models to the external (solar) among simulations of future temperature good agreement of these observations sensible heat biases are unclear. forcing might be helpful for the increase. Important parameters which with ceilometer measurements within improvement of seasonal forecasts. The global average biases differ only affect the net radiative effect of clouds a continental region of the USA. Here, slightly from those in NASA’s previous are cloud cover along with cloud top and this new approach is applied to an area reanalysis, MERRA. In regions where LH cloud base height (CBH). within the stratocumulus region of the is limited by surface moisture availability Southeast Pacific over a time period In this study, we focus on the Southeast and hence sensitive to local precipitation, of 16 years between 2001 and 2016. Pacific which hosts the largest the MERRA-2 LH biases are reduced Furthermore, regional and seasonal subtropical stratocumulus deck on Earth. from those in MERRA, and the direction variabilities of cloud heights are The associated stratocumulus clouds of change is consistent with the investigated. represent a critical but poorly understood precipitation increments from inserting component of the coupled climate
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 78 Section 4 the observed precipitation. However, severe impacts on the society and the Summary statistics from the observed and Remote Sensing Center, Norway), large positive biases remain in some environment. Nonetheless, systematic records and the gridpoint series from K. Andrew Peterson (Met Office, UK), regions where LH is not moisture-limited. biases and uncertainties can affect the low-resolution reanalysis products and Steffen Tietsche (European Centre for ability of reanalysis system in describing corresponding high-resolution dynamical Medium-Range Weather Forecasts), Li Shi The globally averaged anomaly the true state of climate, specially at the downscaling were compared over the (Bureau of Meteorology, Australia), Zhaoru correlations (Ranom) with reference data local scale. period from 1979 to the last decade. Zhang (Shanghai Jiao Tong University), were improved from MERRA toMERRA-2, Remon Sadikhi (University of Hamburg) for both LH (from 0.40 to 0.50 vs. The Italian Peninsula with its complex GLEAM data) and the daily maximum topography can be regarded as an Assessment of ten ocean Ocean reanalysis (ORA) combines T2m in Boreal summer (from 0.64 to interesting test for assessing reanalysis reanalyses in the polar regions observations either statistically or with 0.70, vs. CRU data). There is a strong representation of climatic extremes. We a hydrodynamical model, to reconstruct correspondence between regions of the took advantage of the availability of a Author Dorotea Iovino historical changes in the ocean. greatest improvement in the MERRA-2 new dataset of high-quality, land-based Affiliation CMCC Global and regional ORA products are T2m Ranom, and regions where the precipitation records of observations to Co-authors increasingly used in polar research, but MERRA-2 T2m is most sensitive to compare and evaluate the capability of Petteri Uotila (Finnish Meteorological their quality remains to be systematically the inserted observed precipitation, low-resolution global reanalysis products Institute), Marika Marnela (Finnish assessed. To address this, the Polar ORA suggesting that the observed precipitation and numerical high-resolution CORDEX Meteorological Institute), Meri Korhonen Intercomparison Project (PORA-IP) has did in fact lead to improved T2m. simulations in reproducing precipitation (Finnish Meteorological Institute), Antoine been established following on from the extreme events over Italy. Barthélemy (Université catholique de ORA-IP project (Balmaseda et al. 2015, with other papers in a special issue of In particular, the Med-CORDEX Louvain), Hugues Goosse (Université Assessment of reanalysis Climate Dynamics). precipitation extremes over Italy simulations driven by ERA-Interim will catholique de Louvain), François Massonnet (Université catholique from global reanalysis products, be taken into account. The observation The PORA-IP is constituted under the series was retrieved from the national de Louvain, Belgium and Barcelona COST EOS initiative with plans to review high-resolution simulations and system of climate data SCIA and covers Supercomputing Centre, Spain), reanalyses products in both the Arctic historical observations almost uniformly the country. The James Carton (University of Maryland), and Antarctic, and is endorsed by YOPP Keith Haines (University of Reading, UK), Author Emanuela Piervitali series were selected in order to meet – the Year of Polar Prediction project. severe completeness and continuity Davi Mignac Carneiro (University Currently, the PORA-IP team consists Istituto Superiore per la Affiliation requirements. Potentially inhomogeneous of Reading, UK), Frank Kauker of 23 researchers from 16 institutes and Protezione e la Ricerca records at yearly level were discarded. (Alfred Wegener Institute, Germany), universities. The ORA-IP products with Ambientale (ISPRA) First, a number of contiguous subregions Matthieu Chevallier (Centre National de polar physics, such as sea ice, have been Co-authors were identified using hierarchical cluster Recherches Météorologiques, Météo updated where necessary and collected G. Fioravanti (ISPRA), A. Dell’Aquila analysis based on daily observations of France/CNRS UMR3589, France), in a public database. (ENEA), S. Calmanti (ENEA), F. Desiato precipitations. Marie Drevillon (Mercator Océan, France), (ISPRA), E. Piervitali (ISPRA) Gilles Garric (Mercator Océan, France), In addition to model output, available Then the spatial and temporal Clement Bricaud (Mercator Océan, observational polar climatologies are Reanalysis gridded datasets are a occurrence of moderate extreme rainfall France), Neven Fuc˘kar (Barcelona collected and used in the assessments. valuable source of information for events in each cluster was investigated Supercomputing Centre, Spain), Due to the extensive variety of products, monitoring climate variability and through the calculation of a subset of Vidar Lien (Institute of Marine Research, this database should become a change and assessing the evolution indices from the Expert Team on Climate Norway), Jiping Xie (Nansen Environmental valuable resource outside the PORA- of climate extremes, which can have Change Detection and Indices (ETCCDI). IP community. For a comprehensive
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 79 Section 4 evaluation of the ten ORA products a suppression of high frequency
(CGLORSv5, ECDA3.1, GECCO2, Assessment of the Conventional Benchmarking Northern variability is apparent in the centennial Glorys2v4, GloSea5_GO5, MOVEG2i, Observation Reanalysis (CORe) Hemisphere midlatitude reanalysis products. ORAP5, SODA3.3.1, TOPAZ4 and atmospheric synoptic variability This behaviour does not have a UR025.4) in the Arctic and Southern Author Li Zhang in centennial reanalysis and counterpart in the atmospheric model Oceans several specific diagnostics Affiliation INNOVIM/CPC/NOAA integrations. Since the latter differ from are assessed. numerical simulations Co-authors one of the reanalysis products considered The PORA-IP diagnostics target the Arun Kumar (CPC/NCEP/NOAA), Jeffrey Author Alessandro Dell’Aquila here (ERA-20C) only in the assimilation of following topics: hydrography; heat, Whitaker (PSD/NOAA), Jack Woollen Affiliation ENEA surface observations, it seems reasonable (IMSG), Wesley Ebisuzaki (CPC/NCEP/ salinity and freshwater content; ocean Co-authors to attribute the high frequency variability NOAA), Hyun-Chul Lee (EMC/NOAA) transports and surface currents; mixed Susanna Corti (ISAC-CNR), Antje suppression to the poor coverage of the layer depth; sea-ice concentration and The Conventional Observation data Weisheimer (ECMWF, Uni. Oxford), observations assimilated. thickness; and snow thickness over sea based EnKF (Ensemble Kalman Filter) Hans Hersbach (ECMWF), ice. Based on these diagnostics, ORA atmospheric reanalysis (CORe) was Carol Peubey (ECMWF), Paul Poli Biases in the 20th Century product biases against observed data recently completed at the National (ECMWF, MeteoFrance), Paul Berrisford and their mutual spread are quantified, Centers for Environmental Prediction (ECMWF), Dick Dee (ECMWF), Reanalysis Version 2c and possible reasons for discrepancies (NCEP), for the period of 1950 to 2010. Adrian Simmons (ECMWF) Author Laura C. Slivinski discussed. The observations assimilated include The representation of midlatitude winter Affiliation Univ. of Colorado’s surface station data, radiosondes and So far, we have identified product outliers atmospheric synoptic variability in Cooperative Institute pibals, profilers, aircraft data, and satellite and evaluated the multi-model mean. centennial reanalysis products, which for Research in winds. The EnKF system is based on the We have identified the importance of the assimilate surface observations only, Environmental Sciences latest Semi-Lagrangian Global Forecast atmospheric forcing, air-ocean coupling and atmospheric model simulations System (GFS) T254 L64 model. Co-authors protocol and sea-ice data assimilation constrained by observation-based G.P. Compo (CIRES/NOAA), for the product performance. Moreover, By not assimilating satellite radiances, datasets is assessed. Midlatitude waves J.S. Whitaker (NOAA), P.D. Sardeshmukh we are investigating co-variability CORe avoids the spurious climate activity in twentieth century reanalyses (CIRES/NOAA) between the Arctic Ocean heat content shifts caused by introduction of new (20CR, ERA-20C) and atmospheric and the North Atlantic heat transport, satellites. However, one expects a larger model simulations (AMIP ERA-CLIM) are The NOAA-CIRES Twentieth Century and between the mixed layer depth, lossof accuracy in regions where the compared with those estimated from Reanalysis version 2c (20CRv2c) was oceanic convection, the upper ocean conventional observation network is observationally-complete reanalysis publicly released in 2015, and included hydrography and sea ice. weak such as the Southern Hemisphere products. many improvements over the previous and above the tropopause. version 2 system. However, several We will also present other diagnostic All reanalyses are in good agreement biases and issues in version 2c remain. results which provide closely related This initial assessment focuses on the regarding the representation of the First, version 2c used a digital filter in information for those interested in monthly up to the decadal variability for a synoptic variability during the last its 6 hour first guess fields to damp enhancing model predictive skill over a set of surface and tropospheric variables. decades of the twentieth century. This gravity waves that can cause numerical range of time scales, including seasonal The results are compared with other suggests that the assimilation of surface instabilities. This filter generated artificial to decadal. available reanalyses (R1, CFSR, JRA55c, observations can generate high-quality trends in precipitation that can be seen ERAI and MERRA2). extratropical upper-air fields. In the in the forecast fields: the hour 3-6 first decades of the twentieth century
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 80 Section 4 precipitation forecasts are consistently for East Asia, Institute of Atmospheric The radiosonde data show only and significantly larger than the hour Physics, Chinese Academy of Sciences, small variations and weak trends in Characterisation of Air-Sea 0-3 forecasts. Second, version 2c did China) tropospheric RH over China. Using these Fluxes from Reanalysis Products not include bias correction to marine homogenized observations, the PW from Radiosonde humidity data provide the over the Bay of Bengal during observations. the NCEP/NCAR, NCEP/DOE, MERRA, longest record for assessing changes in the Southwest Monsoon JRA-55, JRA-25, ERA-Interim, ERA-40, In the 19th century, these observations atmospheric water vapor, but they often CFSR and 20CR reanalyses is evaluated Author Alejandra Sanchez-Franks were strongly biased, and have been contain large discontinuities because for the period from 1979-2012 (1970-2001 shown to significantly impact the global of changes in instrumentation and Affiliation National Oceanography for ERA-40). sea level pressure in this time period. observational practices. Centre Finally, 20CRv2c has an apparent high- Results suggest that the PW biases in Co-authors In this study, the variations and trends pressure bias over the high Southern the reanalyses are within ~20% for most E.C. Kent (National Oceanography Centre, in tropospheric humidity (up to 300 latitudes in the early-to-mid 20th century. of northern and eastern China, but the Southampton, UK), A.J. Matthews (Centre hPa) over China are analyzed using a Potential reasons for this include a reanalyses underestimate the observed for Ocean and Atmospheric Sciences, newly homogenized radiosonde dataset. possible model bias, lack of observations PW by 20%–40% over western China, School of Environmental Sciences and There are, however, many spurious in this region at this time, and nonlinear and by ~60% over the southwestern School of Mathematics, University of East changes and discontinuities in the interactions with the data assimilation Tibetan Plateau. The newer-generation Anglia, Norwich, UK), B.G.M. Webber raw radiosonde records resulting from system. Many of these issues are being reanalyses (e.g., JRA25, JRA55, CFSR (Centre for Ocean and Atmospheric changes in instruments, observational addressed in the new 20CR version 3 and ERA-Interim) have smaller root- Sciences, School of Environmental practice, processing procedures, station system currently in development. mean-square error (RMSE) than the Sciences and School of Mathematics, relocations, and other issues. Recently, older-generation ones (NCEP/NCAR University of East Anglia, Norwich, the daily humidity records radiosonde NCEP/DOE and ERA-40). Most of the UK), S.C. Peatman (National Centre derived from about 130 Chinese stations Changes of atmospheric reanalyses reproduce well the observed for Atmospheric Science, Climate and were homogenized using a new approach precipitable water in PW climatology and interannual Department of Meteorology, University developed by Dai et al. (2011). observations and reanalysis variations over China. of Reading, UK), P.N. Vinayachandran It is shown that the homogenization (Centre for Atmospheric and Oceanic over China However, few reanalyses capture the removes the large shifts in the original Sciences, Indian Institute observed long-term PW changes, Author Tianbao Zhao records of humidity resulting from sonde of Science, Bangalore, India). primarily because they show spurious Affiliation Institute of Atmospheric changes in recent years in China, and it wet biases before about 2002. This Meteorological variables and surface flux Physics (IAP), Chinese improves correlation of the precipitable deficiency results mainly from the variables from five reanalysis products Academy of Sciences water (PW) with precipitation and the discontinuities contained in reanalysis are compared and evaluated against in- (CAS) spatial coherence of the PW trend during RH fields in the mid-lower troposphere situ data from the RAMA moored array. recent 40 years. The PW variations Co-authors due to the wet bias in older radiosonde and changes are highly correlated with The reanalysis products, ERA-Interim Jingpeng Zhang (Key Laboratory of records that are assimilated into the those in lower–midtropospheric mean (ERA-I), TropFlux, MERRA2, JRA-55 Regional Climate-Environment Research reanalyses. Thus, more efforts are temperature (r = 0.83), with a dPW/dT and CFSR are specifically assessed for for East Asia, Institute of Atmospheric needed to remove spurious changes slope of ~7.6% K−1, which is slightly their characterisation of air-sea fluxes Physics, Chinese Academy of Sciences, in input data for future long-term higher than the 7% K−1 implied by during the southwest monsoon season China), Tianbao Zhao (Key Laboratory of reanlayses. Regional Climate-Environment Research Clausius–Clapeyron equation with a (JJAS) in the Bay of Bengal. Results constant relative humidity (RH).
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 81 Section 4 show that TropFlux and (to a slightly for evaluating the reanalysis skills to 2016. Results and data sets gathered lesser extent) ERA-I perform best, with CHOCO-JEX: A Research capture and display regional and local during the four IOPs allowed us to the highest correlations and smallest Programme Focused on the atmospheric circulations. contrast diverse reanalysis products biases when compared to the observed such as Era-Interim, MERRA-2, NCEP/ CHOCO Low-level Jet over the The CHOCO-JEX experiment is an meteorological parameters and the NCAR and CFSR. Preliminary results Far Eastern Pacific and Western on-going international and inter- associated fluxes from the RAMA array. show striking cold and wet mid- institutional research program developed Colombia – Reanalysis troposphere biases in the reanalysis over In contrast, MERRA2, CFSR and JRA-55 by Universidad Nacional de Colombia Evaluation both ocean and land. have lower correlations and much higher at Medellín, the General Maritime biases when compared to the observed Author Johanna Yepes Directorate of the Colombian Navy, the This effect is likely related with colder data. In general, however, all products Affiliation Universidad Nacional Colombian Air Force, and the Desert radiative effect of smoothed terrain struggle to capture shortwave radiation de Colombia Research Institute at Reno, Nevada, US. constrained to the reanalysis resolution flux (SWR) and latent heat flux (LHF), with and dispersion of these errors over the Co-authors The main objective of CHOCO-JEX is non-negligible biases ranging from -6 W/ regional ocean by the predominant mid- Germán Poveda (Departamento to expand our understanding of the m2 to 75 W/m2. Further analysis of the tropospheric easterly flow. However, de Geociencias y Medio Ambiente, tropospheric flow characteristics of flux variables showed SWR and LHF to some noisier but warmer and drier Universidad Nacional de Colombia, the Choco Jet through observations, be the largest drivers of the observed biases are observed during organised Sede Medellín, Facultad de Minas, assimilation and reanalysis. To that end, net heat flux variability, thus highlighting convective activity episodes. Such Medellín, Colombia), John F. Mejía four 8-day Intensive Observation Periods the importance of the results from the disturbed convective environments (Desert Research Institute, Reno, NV, (IPO) have taken place, two over land reanalysis product comparison to the appear to be unresolved by all reanalysis United States), Leswis Cabeza (Centro and two over the Pacific off the coast RAMA buoy. products, even by those assimilating de Investigaciones Oceanográficas of Colombia, including the deployment satellite data. Although there are not It was also found that mean fields were e Hidrográficas del Pacífico, Tumaco, of upper-air soundings to monitor the significant differences regarding the consistent with the findings at the buoy Colombia), Carolina Rueda (Subdirección predominant diurnal cycles patterns different reanalysis, NCEP/NCAR (the location, indicating confidence in the de Meteorología, Fuerza Aérea (4 times per day) and the seasonal coarser reanalysis) shows the largest representation of variability across the Colombiana, Bogotá, Colombia) variability. The maritime IOPs took place biases, overestimating temperature basin. Finally, the representation of the during January and November 2016 on The Choco Low-Level Jet (Choco Jet) around 5°C at mid-to-upper levels. intraseasonal variability was investigated has been related to the formation of large board of the ARC Gorgona vessel. through the boreal summer intraseasonal and frequent Mesoscale Convective Such campaigns were constrained by oscillation and it was shown that Systems over the far eastern Pacific the availability of the research vessel, TropFlux and ERA-I perform best at Ocean and inland over the world-record whose schedule was tied to the near capturing intraseasonal climate variability rainy region of western Colombia. The yearly reconnaissance marine campaigns during the southwest monsoon season. structure and dynamic of the Choco aiming to monitoring El Niño/Southern Jet have been studied using reanalysis Oscillation (ENSO) over the Colombian products, but no permanent upper-air coastal waters making part of the Estudio soundings have been put in place on Regional del Fenómeno de El Niño the region neither for improving the (ERFEN). The continental component understanding of the Choco Jet nor of the CHOCO-JEX IOPs was carried out in the city of Quibdó (5°41′32″N, 76°39′29″W) during June and October
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 82 Section 4
While in the winter and summer seasons In the stratosphere the temperature time To achieve this, cyclone and windstorm Comparative evaluation of the these distinctions have a significant series relationship R1 and R2 with R3 time series are low-pass filtered with changes of the temperature in difference both in magnitude and sign. considerably less, especially over the a cut-off frequency of 1/31 years and the troposphere and There is also a non-linear character of oceans. So, on the 100 hPa in January high frequency variability is assessed stratosphere of the Northern the investigated period differences in air over the oceans the correlation is close by calculating the remainder between temperature. This particularly evident to zero. original and low-pass filtered time Hemisphere according to in the Middle troposphere, where at the series. The results suggest partly large reanalyses NCEP and ERA- beginning of the period the difference differences w.r.t. long-term trends of both Interim grows to a value of 0.8°C. Further, since Comparison of Extra-tropical extra-tropical cyclones and windstorms, the second half of the 1980s and until Cyclones and Windstorms in most pronounced during the early 20th Author Vladimir V. Guryanov the beginning of the 21 century, the ERA-20C and NOAA-20CR century. Interestingly, a better agreement Affiliation Kazan Federal University difference goes to zero, and then grows Reanalyses is found for high-frequency variability, Co-authors again. especially over the Northern Hemisphere. K.M. Shantalinskiy (Kazan Federal Author Daniel J. Befort The outcome of this study suggests that At the end of the period the temperature University), Yu.P. Perevedentsev Affiliation University of Birmingham it is difficult to draw reliable information difference, submitted by reanalyses R1 (Kazan Federal University) about long-term variability of extra- and R3, reaching values of 0.4°C. Non- Co-authors tropical cyclone and windstorm events According to the three reanalyses NCEP- linear course of temperature difference S. Wild (University of Birmingham, School during the past century from these two NCAR1, NCEP-DOE2 and ERA-Interim is also reflected in the respective of Geography, Earth and Environmental reanalysis datasets. In contrast, studies (next, respectively, R1, R2 and R3) coefficients of linear temperature trends. Sciences, Birmingham, United Kingdom), focusing on short-term variability of these evaluated differences in air temperature In the same time sign of linear trend T. Kruschke (GEOMAR Helmholtz Centre events might be useful if long-term trends in the free atmosphere averaged on coefficient does not change. In General, for Ocean Research Kiel, Germany), are taken into account. the Northern Hemisphere. The nature in the troposphere according to all U. Ulbrich (Institute of Meteorology, of the impact of these differences reanalyses holds temperature rise. Unlike Freie Universität Berlin, Germany), on the assessment of changes of air the troposphere, in the tropopause region G.C. Leckebusch (University of temperature during the period 1979- and lower stratosphere temperature trend Birmingham, School of Geography, 2013 is defined. Found that reanalysis reversal is observed. Earth and Environmental Sciences, R2 and R3 are more equal temperatures Birmingham, United Kingdom) According to the R1 and R2 on the compared to R1. surfaces of 200 and 100 hPa temperature Extra-tropical cyclones and windstorms The studies were identified differences in decreases, but according to R3 over both hemispheres are analysed dependence of reanalysis from the ocean temperature changes are not statistically for the 20th century in two reanalysis and land. In the lower troposphere over significant. In the middle stratosphere (30 datasets, ERA-20C and NOAA-20CR (v2) the oceans R3 gives lower values of air and 10 hPa) according to all reanalyses (Befort et al., 2016). Analyses focus on temperature compared to R2 and more temperature decreases. long and short-term variability of these so with R1 (average for the year to 1.2°C). events as knowledge on the variability The calculation of the coefficients of the Over land temperature difference is not on different time-scales is of high linear correlation between the time series significant. importance due to their damage-related of temperature according to the R1, R2 impact. and R3 showed that in the troposphere, the correlation is great (more than 0.9).
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 83 Section 4
products are available nowadays that a decrease of performance for others. we investigate how the results differ, Comparison of ten global differ in terms of assimilation technique, This work can thus help choosing an with special focus on wind fields. The reanalysis datasets for assimilated data, atmospheric model, appropriate dataset for the analogue 10m-windspeed and also wind speed precipitation prediction with a archive length, and spatial and temporal method considered, or raise awareness for several model heights up to 100m statistical downscaling method resolution. of the consequences of using a certain are compared with station and mast dataset. observations. ERA-Interim is added in the The context of the application of Author Pascal Horton comparison as a benchmark. analogue methods might drive the choice Affiliation University of Bern of an appropriate dataset, for example Comparison of wind fields from Mean square error, bias, correlation Co-authors when the archive length is a leading European regional reanalyses and other skill scores are investigated Rolf Weingartner (Oeschger Centre for criterion. However, in many studies, a from the UERRA project and to quantify the differences in the four Climate Change Research, Institute reanalysis dataset is subjectively chosen, reanalyses depending on local and of Geography, University of Bern, according to the user’s preferences or COSMO-REA6 temporal scale. In general, the synoptic Switzerland), Stefan Brönnimann the ease of access. The impact of this Author Deborah Niermann patterns are captured well by all regional (Oeschger Centre for Climate Change choice on the results of the downscaling reanalysis productions. There are Affiliation Deutscher Wetterdienst Research, Institute of Geography, procedure is rarely considered and no examples for each regional reanalysis University of Bern, Switzerland), comprehensive comparison has been Co-authors outperforming the other ones at certain Charles Obled (Laboratoire d’étude undertaken so far. In order to assess Andrea K. Kaiser-Weiss (Deutscher locations. des Transferts en Hydrologie et the impact of the archive’s quality in the Wetterdienst), Michael Borsche For special case studies, the comparison Environnement, LTHE, Université de analogue method, ten global reanalysis (Deutscher Wetterdienst), Frank Kaspar with independent or dependent wind Grenoble-Alpes, Grenoble, France) datasets were compared in seven (Deutscher Wetterdienst) observations could hint on abilities and versions of the analogue method, over The analogue method allows predicting Within the FP7 project UERRA limitations of each reanalysis system, 300 precipitation stations in Switzerland. precipitation by means of a statistical (Uncertainties in Ensembles of Regional which has to be investigated further. downscaling of synoptic predictors. To Despite the fact that all reanalysis ReAnalyses) several new large data sets Here we give a first assessment of predict the precipitation for a target day datasets might be considered accurate are produced, mainly for the European uncertainties in UERRA’s regional of interest, analogue days are sought for central Europe, differences in terms of CORDEX domain. At their boundary, reanalyses with the intention to guide in long archives of synoptic predictors, prediction performance were identified. these regional reanalyses are driven potential users. typically from reanalysis datasets. Satellite-based products generally similarly by ERA-Interim (and ERA-40 for showed higher skills. There were no years before 1979). The various regional A certain number of analogue days are overall winner amongst these, but reanalyses employ different regional then extracted and their corresponding some datasets were found to perform models: UM by UKMO, HARMONIE by observed precipitation is used to better for different methods. MERRA-2 SMHI, MESCAN by MeteoFrance and establish a conditional empirical provides SLP data particularly skillful COSMO by DWD. distribution, which is the statistical in the analogue method. Geopotential prediction for the target day. Most of Their data assimilation systems heights from CFSR show slightly higher the recent analogue methods rely on range from nudging of conventional skills, as well as the vertical velocity the atmospheric circulation as the main observations (DWD), optimal interpolation from JRA-55. Increasing the complexity predictor, with additional predictors for surface observations (MeteoFrance), of the analogue method was relevant based on moisture, air temperature, and 3D-Var for the full observing system only for certain datasets, while it led to vertical velocity. Many different reanalysis (SMHI) to 4D-Var for UKMO. Here
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 84 Section 4
throughout the model simulation. Parameters such as: surface pressure, existing ones. The simulations were COSMO ensemble reanalysis Therefore, the system can be utilized relative humidity, 2-m air temperature and performed for January 2010. The chosen system for Europe: diagnostics with a deterministic forcing at the lateral 10-m wind speed have been simulated parameterizations will be applied for long of quality of data assimilation boundaries. for the purpose of further implementation term 2010-2015 hindcast. in fjord –ocean water circulation, and uncertainty estimates Here, the system is used for the hydrodynamic model. Special emphasis production of a 21 member ensemble Author Maarit Lockhoff was put on obtaining proper wind Duration and Decay of Extreme for an initial 5 year time period. In this Affiliation University of Bonn conditions. Vortex Events in the Polar presentation, we focus on the evaluation Stratosphere: Comparison of Co-authors of the quality of the data set using basic Results from simulations with different M. Borsche (Deutscher Wetterdienst), diagnostics for observations and data reanalysis data sets used for the the ECMWF Seasonal Forecast L. Bach (Deutscher Wetterdienst), assimilation monitoring as well as on the boundary condition: ECMWF – Era Model with Reanalyses C. Schraff (Deutscher Wetterdienst), probabilistic evaluation using standard Interim and NCEP – Climate Forecast Author Yvan Orsolini K. Stephan (Deutscher Wetterdienst), measures for ensemble reliability and/or System Reanalysis (CFSR) have been NILU – Norwegian J. Keller (Deutscher Wetterdienst) resolution, e.g. spread-skill relation, rank compared. The results have been Affiliation Institute for Air Research histograms, Brier/CRPS scores. validated against observations performed The objective of the FP-7 funded in the Polish Polar Station in Hornsund Co-authors project Uncertainties in Ensembles of The provided uncertainties are also and measurements conducted in the Kazuaki Nishii (Mie University), Regional Reanalyses (UERRA) is to evaluated by comparison against other Bayelva/Ny-Ålesund in Norwegian Hisashi Nakamura (University of Tokyo) produce ensembles of European regional ensemble reanalyses produced within synoptic station. Preliminary results atmospheric reanalyses of Essential UERRA. We investigate extreme stratospheric show good agreement with 2-m Climate Variables thereby providing polar vortex events in the operational temperature, relative humidity, surface estimates for the associated uncertainties seasonal forecast model (System 4) of pressure. However results show high bias in the data sets. One of these data Customizing the Weather the European Centre for Medium-Range associated with higher wind speeds. sets is the high resolution probabilistic Research and Forecasting Model Forecasting (ECMWF) in comparison COSMO-EN-REA12 reanalysis (Bach for west Spitsbergen fjords For the sake of large wind impact on to re-analysis data during the Northern et al. 2016) which is based on the non- – wind hindcast the water circulation in fjord, especially Hemisphere winter. While previous hydrostatic limited-area model COSMO due to the phenomena of “topography studies have documented both weak (COnsortium for Small-scale MOdeling). Author Szymon Kosecki tunnelling” along the fjord axis, further vortex events (WVE) and strong vortex It is produced at 12-km grid spacing Affiliation Centre for Polar Studies studies have been performed considering events (SVE) in models or re-analyses, and with hourly resolution covering the Co-authors specially attention on the wind field. there has been little focus on the CORDEX-EUR11 domain. The applied K.S.A. Kjetil Schanke Aas University of The problem has been diagnosed as duration of these events and their decay ensemble data assimilation method Oslo, J.J. Jaromir Jakacki, L.D.G. Lidia a bad representation of subgrid-scale processes. is an ensemble nudging scheme. In Dzierzbicka-Głowacka orographic effects. To this end, we use a 5-member set this scheme, an ensemble of different Therefore the dedicated of 7-month reforecasts made over the deterministic nudging realizations is The state-of-the-art Weather Research parameterizations have been applied. period 1981-2014, and compare with generated by perturbing the observations and Forecasting Model has been The presentation points up the the Japanese 55-year Reanalysis (JRA- with perturbations reflecting the applied for the West Spitsbergen fjords: problem of lack of topographic data 55) dataset. Strong and weak vortex observation errors. A major benefit of this Hornsund and Kongsfjorden. for Arctic regions and unreliability of events are classified into short (less approach is that uncertainty is generated
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 85 Section 4 than 10 days) and long (no less than The impact of aerosols, as evidenced Snow cover variability has significant 20 days) events, and each category is Energy budgets and transports: by the sensitivity experiments with effects onlocal and global climate composited. global evolution and spatial ECHAM5-HAM, sets up an inter- evolution. By changing surface en-ergy hemispheric gradient in the TOA and fluxes and hydrological conditions, In particular, we examine how the patterns during the twentieth surface budget after 1960, increasing changes in snowcover can alter characteristics of each category (i.e. century as estimated in two the total poleward transport in the atmospheric circulation and lead to frequency of occurrence, anomalous AMIP‐like experiments Northern Hemisphere and decreasing remoteclimate effects. To document such winds and E-P fluxes) are represented it in the Southern Hemisphere. This multi-scale climate ef-fects, atmospheric in the forecast model in comparison to Author Valerio Lembo feature is not found in ERA-20CM, reanalysis and derived products offer the reanalyses. Obviously, long WVEs Affiliation University of Hamburg suggesting a substantial difference in the theopportunity to analyze snow variability (SVEs) tend to be accompanied by longer Co-authors representation of the aerosol forcing in in great detail farback to the early 20th enhancement (suppression) of upward- D. Folini (ETH Zürich), M. Wild (ETH the two experiments. century. propagating planetary wave than their Zürich), P. Lionello (Università del Salento) short counterparts. Both types begin in SST variations do not seem to induce So far only little is know abouttheir the same fashion with a barotropic zonal The 20th century evolution and spatial long-term variations in the patterns of quality. Comparing snow depth in four wind anomaly extending from 1 hPa to patterns of the Top-of-Atmosphere TOA budget and related total meridional long-term re-analysis datasets with the lower stratosphere, but in the latter (TOA), atmospheric, and surface energy transport. On the contrary most of Russian in situ snow depth data, wefind case, sustained wave forcing from the budgets (EB) are investigated in this the surface and atmospheric budget a moderately high daily correlation upper-troposphere allows for persistence work. Total, atmospheric and oceanic and transport inter-annual variability (around 0.6–0.7), which is comparable and further downward propagation of the meridional energy transports are also is attributable to the evolution of SST, to correlations for the recent era wind anomalies. computed from the EBs. and much more agreement is observed (1981–2010), and a good representation among the two models in this respect. of sub-decadal variability. However, However, short WVEs uniquely show an Two AMIP-like ensemble simulations the representation of pre-1950 inter- E-P flux divergence anomaly dominated are considered: Integrated Forecast decadal snowvariability is questionable, by its meridional component in their System (IFS) simulations of the ERA- Eurasian snow depth in long- since reanalysis products diverttowards ending phase, which suggests that 20CM experiment, and ECHAM5-HAM term climate reanalyses different base states. barotropic instability abruptly terminates model simulations. With the latter, these events. The characteristics additional sensitivity experiments are Author Martin Wegmann Limited availability of indepen-dent carried out by constraining either Sea- of precursory upper-tropospheric Affiliation University of Grenoble long-term snow data makes it difficult to Surface Temperatures (SST) and Sea-Ice disturbances are also examined for each Co-authors assess the exactcause for this bifurcation category, in both the seasonal forecast Cover (SIC) or aerosol concentrations to in snow states, but initial investiga- climatological values. Yvan Orsolini (NILU), Olga Bulygina model and the reanalyses. (All-Russian Research Institute of tions point towards representation of The recent decades estimates of the Hydrometeorological Information – the atmosphere rather than differences EB are in reasonable agreement in the World Data Centre), Alexander Sterin in assimilated data or snow schemes. two models, while they are not for what (All-Russian Research Institute of Thisstudy demonstrates the ability of concerns the global scale evolution. Hydrometeorological Information – long-term reanalysis to re-produce snow Particularly, in the 1970s ERA-20CM World Data Centre), Stefan Brönnimann variability accordingly. shows a fast transition from negative to (University of Bern) positive EBs at Top of Atmosphere (TOA) that is not found in ECHAM5-HAM.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 86 Section 4
synthetic spectra based on the ARM- reanalysis data, ARM sounding profiles added value of the regional reanalyses Evaluate reanalysis with SGP are used to establish observation and AIRS-L2 physical retrievals. But such compared to existing global reanalyses, simultaneous in-situ and satellite uncertainties. MERRA-2 and ERA-interim radiance comparisons clearly disclose the global radiation of ERA-Interim is observations: bracketing the data at the same 51 occasions are also the biases in the middle and upper included into this study. observational uncertainties used generate synthetic AIRS spectra. troposphere and avoid any uncertainties associated with level-2 retrievals. For AIRS channels in the CO band Author Xianglei Huang 2 Evaluating groundwater sensitive to the temperature from resources by means of global Affiliation The University surface to 800hPa but not to water Evaluating global radiation of of Michigan datasets vapor, both reanalyses show negative regional reanalyses over Europe Co-authors differences from the AIRS observation against the satellite-derived Author Paolina Bongioannini Xiuhong Chen (Univ. of Michigan), and such differences are much larger Cerlini SARAH dataset Norman G. Loeb (NASA/Langley), Xiquan than the observation uncertainties (OU) Affiliation Centre for Climate and Dong (Univ. of Arizona), Baike Xi (Univ. established above. For channels sensitive Author Michael Borsche Climate Change, of North Dakota), Erica Dolinar (Univ. to temperature from 400-200hPa, Affiliation Deutscher Wetterdienst University of Perugia of North Dakota), Michael Bosilovich the MERRA-AIRS difference is much Co-authors (NASA/GSFC), Seiji Kato (NASA/Langley), smaller than the OC while the ERA-AIRS Co-authors S. Meniconi (Centre for Climate and Paul Stackhouse (NASA/Langley), difference is comparable to the OU. A. K. Kaiser-Weiss (Deutscher Climate Change, University of Perugia), William Smith Jr. (NASA/Langley) Wetterdienst), F. Kaspar (Deutscher For channels sensitive to temperature Wetterdienst) B. Brunone (Centre for Climate and Every observation has its own between 800 and 400 hPa, reanalysis Climate Change, University of Perugia) uncertainty. This naturally leads to a and AIRS difference is smaller than Within the European Framework Climate change influences the question in the evaluation of reanalysis or comparable to the OU. The BT Programme 7 project UERRA hydrological cycle with direct effects against observations: how good is good differences between both reanalyses (Uncertainties in Ensembles of Regional on groundwater resources, one of enough? Here we answer this question and AIRS are negative and significantly Reanalyses) several regional reanalyses the most important supply source for by using two independent observations larger than the OU for the channels in are produced. The grid size resolution of human consumption and irrigation. to bracket observation uncertainties, the H O band. Such differences cannot the reanalyses is comparable to the one 2 In the framework of assessing water and then using such uncertainties in be explained by temperature difference of the satellite-derived solar radiation balance and the related hydraulic works the evaluation of MERRA-2 and ERA- alone. The only possible explanation is estimate SARAH v002 produced by CM for water supply, it is crucial to correlate interim reanalysis. Using cloud radar that both reanalyses have positive biases SAF (Satellite Application Facility on quantitatively climate trends, precipitation observations, we have identified 51 for the water vapor from 800 to 200 hPa. Climate Monitoring). and groundwater behaviour. In this paper, occasions from 2004 to 2013 when AIRS Similar positive humidity biases can In this study we compare solar radiation the use of global atmospheric datasets on NASA Aqua flied over the ARM SGP be seen for the comparisons between of all regional reanalyses of that project as a reliable tool for water resources site with no cloud in a 30km-by-30km reanalyses and AIRS over the 30-40N (from the National Meteorological management is further explored. proximity. zone, indicating that it is a systematic Services of Sweden (SMHI), Great In fact, in a previous paper (Cerlini et Using the ARM SGP soundings, we then bias instead of any coincidence over the Britain (UKMO), France (Météo France), al., 2017), ERA-Interim reanalysis of computed synthetic AIRS spectra and ARM site. We further show that such and Germany (DWD)) with the satellite meteorological observations made by compared them with observed AIRS differences in BT are consistent with the estimate on instantaneous to multi- the European Centre for Medium-Range spectra. The brightness temperature differences seen in the comparison of decadal time scales within the period Weather Forecasts (ECMWF) have (BT) differences between AIRS and the 1982 to 2014. In order to estimate the
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 87 Section 4 been compared to the local water table of wind is 1.0-4.5m/s. The temperature measurements given by the monitoring Evaluating the coherence of Evaluation of CFSv2, ERA- observations of three sites show a good network managed by the Regional reanalyses’ North Atlantic Interim and MERRA2 datasets consistent against CFSv2, ERA-Interim, Agency for Environmental Protection atmospheric circulation using with intensive radiosonde data except for the 2165m high site Jinchuan, of the Umbria Region (ARPA Umbria dynamical proxies in the lee of the Tibetan plateau which shows a peak RMSE about 8k at Italy). The pointed out good correlation 200hPa level. between the trend of soil moisture Author Davide Faranda Author Zhiwei HENG The RMSE between temperature – the result of precipitation over all Affiliation CNRS (LSCE CEA-Saclay) Affiliation Institute of Plateau observation and MERRA2 is about 4k meteorological space-time scales – Co-authors Meteorology, China than those of CFSv2 and ERA-Interim. and local water table data of unconfined M.C. Alvarez-Castro (LSCE-CNRS Meteorological It is also found that, the observations of aquifers authorises further in-depth CEA Saclay, France), D. Rodriguez Administration, Chengdu the lower altitude sites are relatively more analyses. (LSCE-CNRS CEA Saclay, France), similar than higher sites. The intensive Southwest China vortex In the line with such promising results, G. Messori (MISU Stockolm, Sweden), observation experiment is conducted in this paper meteorological observations P. Yiou (LSCE-CNRS CEA Saclay, France) in Sichuan province (in the lee of the from ERA-Interim and ERA5 reanalyses Evaluation of circulation type We evaluate the coherence of the Tibetan Plateau), from 21 June to 31 July are compared with the aim of evaluating: classifications in five global dynamical properties of atmospheric in recent years. This study collects about i) the effect of the different models reanalyses over selected Euro- circulation over the North Atlantic for 1900 high-quality radiosonde data from 4 and procedures used to obtain global several reanalyses datasets (20CR, of the meteorological stations, from 2014 Atlantic and South-American datasets, and ii) the role played by ERA20CM, CERA20C, NCEP-NCAR). to 2016, to evaluate the quality of the domains in winter the characteristics of data on which commonly used global datasets ERA- reanalyses are based (e.g., their temporal We measure the instantaneous metrics Author Jan Stryhal Interim (interim ECMWF Re-Analysis), and spatial resolution). Attention is defined in Faranda et al. (Scientific CFSv2 (NCEP Climate Forecast System Affiliation Charles University & focused on the behaviour of water fluxes Reports, 2017), namely the number of Version 2) and MERRA2 (the second Academy of Sciences towards water table as a preliminary degrees of freedom and the persistence Modern-Era Retrospective analysis for of the Czech Republic phase of the water budget assessment. of daily averaged sea-level pressure fields. Research and Applications) over this Co-author In fact, reanalyses produce the land We find that, before 1948, the ensemble steep terrain region. Radan Huth (Department of Physical surface forecast for soil moisture at four means of all reanalyses suffer from a Geography and Geoecology, Faculty levels (0-7; 7-28; 28-100; and 100-289 cm non-physical reduction of the number of The stations vary from 520m to 2900m in of Science, Charles University, Prague, from the ground level, respectively). degrees of freedom originating from the the altitudes, providing comprehensive Czech Republic; Institute of Atmospheric large spread of the ensemble members. observations in the basin and in the The ultimate goal of this research is Physics, Academy of Sciences of the highland. The root mean-square errors to check whether the global datasets On the contrary, ensemble members Czech Republic, Prague, Czech Republic) (RMSE) of relative humidity, meridional – specifically the behaviour of the soil of different datasets show significant wind, zonal wind show general similarity Atmospheric reanalyses have been moisture volumetric content – may allow shits of the dynamical proxies over time. between observations and the three widely used in synoptic-climatology to estimating the available groundwater These shifts are however not coherent global datasets. study large-scale atmospheric circulation resources at a regional scale. among different reanalyses datasets. and its links to local weather and A comparison with large ensemble of In terms of relative humidity, the RMSE climate, including the role that changes climate models is also presented. The is about 10%-20% below 400hPa, and in circulation play in trends of climatic effects of the seasonal cycle are analysed. raises to 30% at higher levels. The RMSE
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 88 Section 4 variables, and to evaluate outputs of ranges, there is a better agreement climate models. In this kind of research, Evaluation of ERA-Interim and between the frequency of occurrence of Evaluation of JRA-55C, an automated classifications of daily mean CCMP wind fields for wave CCMP and measured wind speeds. For Atmospheric Reanalysis sea level pressure or geopotential height simulation in the Persian Gulf wind speed above 10 m/s, occurrence Assimilating Conventional patterns represent one of the most frequency of ERA-I and CCMP winds Observations Only prominent approaches. Author Mohammad Hossein are much less than that of the measured Kazeminezhad winds, such that, there is no wind speed Author Chiaki Kobayashi Such classifications define a few Affiliation Iranian National Institute above 12.5 m/s from ERA-I and CCMP distinguished circulation types (CTs), Affiliation Meteorological Research for Oceanography and datasets in the Lavan station. to which daily patterns are classified Institute Atmospheric Science according to a similarity measure. So To investigate the sensitivity of the Co-authors far, no study has aimed at comparing In this study performance of ERA-Interim wave model to the wind field, several H. Endo (Meteorological Research classifications (e.g., CT occurrence (Dee et al., 2011) and CCMP (Atlas et wave simulations in the period of Institute), H. Kamahori (Meteorological frequencies) in multiple reanalyses, al., 2011) wind fields were evaluated for 1/10/2009-7/7/2010 were carried out Research Institute) and, in general, the effect of reanalysis using WAVEWATCH III model forced wave simulation in the Persian Gulf. One As a subset of the Japanese 55- selection on results has been rather with ERA-Interm and CCMP wind of the shortcomings in the Persian Gulf year Reanalysis (JRA-55) project, the marginalized. The present research fields. Application of CCMP wind field region is the lack of sufficient measured Meteorological Research Institute of the focuses on quantifying the differences in compared to ERA-I wind field sometimes overwater wind data as well as results Japan Meteorological Agency conducted CT frequencies in five global reanalyses results in larger wave height and of atmospheric numerical models which a global atmospheric reanalysis that (ERA-40, NCEP-1, JRA-55, ERA-20C, sometimes vice versa. To evaluate the specifically calibrated for this region. assimilates only conventional surface 20CRv2) during 1961–2000 winters. performance of applied wind fields, the and upper air observations, with no use Therefore, it is common that the forcing simulated and measured significant wave We focus on two spatial domains,– of satellite observations, using the same wind data for wave models are derived height (Hs) and peak spectral period Euro-Atlantic and South-American–, data assimilation system as the JRA-55. from the global wind resources such as (Tp) were compared and error indices each represented by several smaller ECMWF (European Center for Medium were calculated. Results indicated that The project, which name is “JRA- subdomains covering regions with range Weather Forecasting). To do so, application of ERA-I and CCMP led to an 55 Conventional (JRA-55C)”, aims to various climates and numbers of wind rose from measurements, ERA- average underestimation of 30% for Hs produce a more homogeneous dataset observations assimilated by reanalysis Interim and CCMP wind were compared and 10% for Tp in both stations. over a long period, unaffected by models. Furthermore, for selected in Lavan and Siri islands stations located changes in historical satellite observing subdomains, it will be shown how in the northern Persian Gulf in the period systems. In addition, JRA-55AMIP, the choice of the reference reanalysis of 1/10/2009-7/7/2010. which is the AGCM experiment, is affects validation of models by ranking also conducted. In the experiment, the 32 CMIP5 GCMs according to their The measured wind data are collected same model and the same boundary skill to simulate the winter CTs. A total from synoptic stations located on islands such as the observed SST and sea-ice, of eight classification methods will be and may affected by the land. Therefore, greenhouse gases, ozone and aerosols used in parallel to minimize the effect of the recorded wind speeds may be smaller as in the JRA-55 and JRA-55C, are subjective, unavoidable methodological than those occurred overwater. The most prepared. choices on results. frequently occurring wind speed in both stations was in the range of 2.5-5.0 m/s. As can be seen, almost in all wind speed
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 89 Section 4
We evaluated JRA-55C by comparing EOS intends to provide a uniform of Meteorology and Climatology these three datasets, JRA-55, JRA-55C Evaluation of Ocean Syntheses: protocol for the evaluation of ocean MeteoSwiss, Zurich, Switzerland), and JRA-55AMIP. The main results are a COST Action to improve our syntheses, and seek adhesion to this O. E. Tveito (Norwegian Meteorological as follows. On the basis of forecast skill, knowledge about ocean protocol from scientists working on Institute, Oslo, Norway) and L. Cantarello the quality of the JRA-55C is inferior to syntheses and reanalyses ocean reanalyses worldwide. This work (Norwegian Meteorological Institute, Oslo, that of the JRA-55, but the JRA-55C has builds-up on previous efforts made within Norway, Federal Office of Meteorology better temporal homogeneity than the Author Aida Alvera Azcarate the GODAE and ORA-IP initiatives for and Climatology MeteoSwiss, Zurich, JRA-55. The climatological properties Affiliation University of Liege intercomparisons. The metrics proposed Switzerland of the JRA-55C are similar to those of need to facilitate the assessment Co-authors Re-analysis aims at providing long- the JRA-55 in the troposphere and lower of progress in the quality of ocean M. Drevillon (Mercator Océan, France), term, high-resolution, dynamically stratosphere, except for high southern reanalyses. Detailed metrics are needed K. Haines (University of Reading, UK), consistent climate datasets useful for latitudes. QBO is properly represented also for regional ocean reanalyses and S. Masina (CMCC, Italy), K.A. Peterson environmental applications. Usually, in JRA-55C, which is not appeared in for process-based intercomparisons. (Metoffice, UK), A. Storto (CMCC, Italy) these datasets cover a time period of JR A55AMIP. This protocol, still under development, several decades and they assimilate The COST Action “Evaluation of Ocean The pattern correlation of spatial will be presented at the conference in high-quality and detailed observations Syntheses” (EOS) was initiated in 2014 precipitation anomaly of JRA-55C order to foster discussion and obtain into the atmospheric analysis. In UERRA, in order to establish and consolidate a shows temporal homogeneity through feedback from reanalysis experts. The a FP7 research project of the EU, several network of European scientists working the reanalysis period. The radiation main achievements of the EOS network regional deterministic and ensemble on the generation and evaluation of balance of JRA-55 and JRA-55C has and a brief presentation of the activities re-analyses, as well as downscaling ocean syntheses and reanalyses. The characteristics similar to those of JRA-55 organised in the following months will be procedures based on these re-analyses, main goals of EOS are to improve the AMIP (model). Therefore, improvement also presented. are calculated for the past 30-50 years. coordination of the European efforts in of the radiation balance of the model is the evaluation of ocean syntheses, to With respect to precipitation, regional reflected directly in the balance of the optimize their use and value, to ease their re-analyses are expected to better reanalysis field. Evaluation of precipitation in access, to promote their improvement UERRA regional re-analysis represent high threshold events than and to raise confidence in their quality. datasets for complex terrain global re-analysis. The aim of the present study is to evaluate daily precipitation Through the activities organised by regions data from the new regional re-analyses of the network, regional intercomparison UERRA in two topographically complex initiatives of ocean reanalyses have been Author Cristian Lussana sub-regions of Europe, namely the started (polar regions, Atlantic Ocean). Affiliation Norwegian European Alps and Fennoscandia. EOS is also co-organising future plans Meteorological Institute of the Ocean Reanalysis Comparison Co-authors Our focus is on aspects of re-analysis Project (ORA-IP) for, among other things, F. Isotta (Federal Office of Meteorology uncertainty that may be relevant for establishing a protocol for the next and Climatology MeteoSwiss, Zurich, hydrological applications, notably intercomparison exercise, discusssing Switzerland), B. Casati (Meteorological the dependence on spatial scale. In strategies for the near real-time extension Research Division, Environment and comparison with verification of numerical of the current reanalyses and identifying Climate Change Canada, Dorval weather predictions, the evaluation of recommendations and good practices for (QC), Canada), C. Frei (Federal Office reanalysis data must focus more on the reanalysis production. assessing the spatial smoothing and
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 90 Section 4 filtering properties of the atmospheric uncertainties, the magnitude of which space–time scales, such as equatorial being of direct societal importance. model considered, while the forecast may be significant at the resolution of waves, compared with JRA-25 during the Ocean reanalysis systems are critical for error is less relevant because it is modern re-analyses and, hence, could satellite era, and improved the temporal the evaluation of this ocean monitoring expected to be rather small due to the affect a scale-dependent evaluation. consistency compared with the older indicator as they deliver a 3-D view frequent data assimilation cycles. This difficulty is addressed in the Alpine reanalyses throughout the reanalysis on the interior of our oceans and its section of our analysis by introducing period, although some issues in JRA-55 temporal changes from a combined The evaluation is based on a comparison a new probabilistic rain-gauge dataset were also identified. use of ocean observing systems and against conventional climatological which explicitly quantifies uncertainties numerical model techniques. datasets derived from spatial analyses by ensembles. of high-resolution rain-gauge networks. Evaluation of steric sea level In this analysis we will present results The Alpine rain-gauge dataset covers from the CMEMS ensemble on the evaluation of global and regional territories of seven countries and Evaluation of representation of of ocean reanalysis ocean steric sea level under the Ocean encompasses more than 5300 daily atmospheric circulation and State Report activity from a multi- rain-gauge observations on average. climate variability in the JRA-55 Author Andrea Storto reanalysis approach based on an In Fennoscandia, we focus on Norway, Affiliation CMCC ensemble product of the Copernicus Sweden and Finland where a dataset reanalysis Marine Service. Co-authors of approximately 2000 daily rain-gauge Author Yayoi Harada Karina von Schuckman (Mercator Océan), In addition, consistency checks through observations is available. Affiliation Meteorological Research Magdalena Balmaseda (ECMWF), physical budget constraints with the Our evaluation strategy combines Institute/Japan Clement Bricaud (Mercator Océan), combined use of climate observing “standard” verification measures of meteorological Agency Charles Desportes (Mercator Océan), systems and reanalyses are performed systematic errors (such as the bias and Marie Drevillion (Mercator Océan), as they have a large potential to deliver root mean squared deviations) with This study investigates the quality of Yann Drillet (Mercator Océan), Clotilde a robust uncertainty assessment spatial verification methods, which the Japanese 55-year Reanalysis (JRA- Dubois (Mercator Océan), Gilles Garric and to shed new light on unresolved account for the presence of features and 55, Kobayashi et al. 2015), which is the (Mercator Océan), Laura Jackson (UK climate science issues. In particular, for the coherent spatial structure inherent second global reanalysis constructed by MetOffice), Matt Martin (UK Met Office), complementary information coming in precipitation fields, and provide the Japan Meteorological Agency (JMA), Simona Masina (CMCC), Sandrine Mulet from altimetry and gravimetry satellite enhanced diagnostics (e.g. scale- comparing with other reanalyses and (CLS), Coralie Perruche (Mercator Océan), missions is helpful for qualifying the separation approaches inform on the observational datasets. Improvements Isabelle Pujol (CLS), Drew Peterson reanalysis datasets. For this purpose, scale-structure and scale-dependence of were found in the representation of (UK Met Office), Patricia de Rosnay the sea level budget has been applied, the error). atmospheric circulation on the isentropic (ECMWF), Richard Wood (UK Met Office), allowing an assessment of the multi- surface and in the consistency of Hao Zuo (ECMWF) reanalysis approach and the reliability Scale dependence of the uncertainty/ momentum budget based on the mass- of the ensemble mean. accuracy is examined in our analyses weighted isentropic zonal mean (MIM) Thermal expansion of seawater is a major by considering (nested) hydrological method. driver of global mean sea level change. catchments of variable size and by Quantifying the effect of the seawater decomposing precipitation fields into The representation of climate variability density changes on sea level variability is (orthogonal) wavelets of variable scale. in several regions was also examined. of crucial importance for climate change A difficulty for an unbiased evaluation The results indicate that JRA-55 studies, as the cumulative sea level of re-analyses is that reference generally improved the representation rise can be regarded as an important datasets themselves are subject to of phenomena on a wide range of climate change indicator, as well as
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 91 Section 4
For comparison purposes, we perform assimilated. While this change in data Evaluation of the ensemble the analyses on the 56 members and streams does lead to a discontinuity in Evaluation of water cycle reanalysis ability to reproduce the ensemble mean of the 20CRv2c the assimilated ozone fields in MERRA-2, components in the Upper Blue mechanisms leading European reanalysis, as well as for another making it not useful for studies in decadal Nile basin based on an ensemble temperature extremes reanalyses products, ERA-20C and (secular) trends in ozone, this choice of water resources reanalysis NCEP, in order to properly estimate and was made to prioritize demonstrating the Author M. Carmen Alvarez- discuss the uncertainties and be capable value NASA’s high-quality research data products. Castro to assess the ability of reanalyses to in the reanalysis context. Author Marika Koukoula reproduce the mechanisms that lead to Affiliation Laboratoire des The MERRA-2 ozone is compared with Affiliation University of Connecticut Sciences du Climat European temperature extremes. independent satellite and ozonesonde Co-authors et de l’Environnement data, focusing on the representation of Efthymios I. Nikolopoulos, Zoi Dokou, (LSCE/IPSL/CEA-CNRS) Evaluation of the Ozone Fields the spatial and temporal variability of Semu Moges, Amvrossios C. Bagtzoglou, Co-authors in NASA’s MERRA-2 Reanalysis stratospheric and upper-tropospheric (University of Emmanouil), N. Anagnostou D. Faranda, P. Yiou. (LSCE/IPSL, France) ozone. The comparisons show (Department of Civil and Environmental Author Steven Pawson agreement within 10% (standard The atmospheric circulation is an Engineering, University of Connecticut) deviation of the difference) between important driver of temperature Affiliation NASA GSFC MERRA-2 profiles and independent Availability of multiple global water variability. Weather regimes are typical Co-authors satellite data in most of the stratosphere. resources reanalysis (WRR) products atmospheric circulation patterns K. Wargan (NASA GSFC), G. Labow The agreement improves after 2004, has provided a unique opportunity to obtained using a cluster analysis. Climate (NASA GSFC), S Frith (NASA GSFC), when EOS Aura data are assimilated. advance understanding of terrestrial decadal variability can induce changes N. Livesey (NASA JPL), G. Partyka The standard deviation of the differences hydrologic processes at regions in those frequencies. We investigate how (NASA GSFC) between the lower-stratospheric and where in situ information is sparse or the atmospheric circulation might have The assimilated ozone product from the upper-tropospheric MERRA-2 ozone nonexistent. Africa is a continent where evolved in the past century, focusing Modern-Era Retrospective Analysis for and ozonesondes is 11.2% and 24.5%, this aspect is particularly emphasized specifically on the weather regimes Research and Applications, Version 2 respectively, with correlations of 0.8 because it is generally characterized associated with temperature extremes in (MERRA-2), produced at NASA’s Global and above. This is indicative of a by sparse hydrologic observations Western-Europe. Modeling and Assimilation Office (GMAO) realistic representation of the UTLS while at the same time there is need for The 20CR is the longest reanalysis is summarized. The reanalysis begins ozone variability in MERRA-2. After efficiently managing water resources available that assimilates only surface in 1980 with the use of retrieved partial- 2004, the upper tropospheric ozone in to enhance food and water security in pressure observations since 1851 column ozone concentrations from a MERRA-2 shows a low bias compared the area. Managing water resources in using an Ensemble Kalman Filter data series of Solar Backscatter Ultraviolet to the sondes, but the covariance with a sustainable manner requires at the assimilation method, producing an Radiometer (SBUV) instruments on NASA independent observations is improved very least an adequate characterisation ensemble of 56 members of reanalysis and NOAA spacecraft. compared to earlier years. Case studies of hydrological fluxes (precipitation, fields. Therefore, the differences among demonstrate the integrity of MERRA-2 streamflow, evapotranspiration, Beginning in October 2004, retrieved groundwater) and states (soil moisture) the 56 members provide an estimate of ozone profiles from the Microwave Limb analyses in representing important the uncertainty for the reanalysis. features such as tropopause folds. at monthly, seasonal and annual scale. Sounder (MLS) and total column ozone In this work we present a comprehensive from the Ozone Monitoring Instrument evaluation of water cycle components (OMI) on NASA’s EOS Aura satellite are
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 92 Section 4 for the Upper Blue Nile basin in Ethiopia thus, an evaluation of these products is estimated from four state-of-the-art WRR Front statistics in modern Global evaluation of ERA-Interim strongly needed before to use them in products. reanalyses using an automated and other global rainfall applications. Specifically, evaluation is carried out front recognition over East Asia estimates over land without Classical validation of satellite and for two datasets produced through Author Eunho Choi ground-based observations by reanalysis products still relies on the NASA’s Land Data Assimilation System use ground networks of rain gauges Affiliation Seoul National University using Triple Collocation Analysis (LDAS) at global (GLDAS v2) and regional hence the problem of investigating the (FLDAS) scale and two versions (tier Co-authors Author Christian Massari satellite and reanalysis performances in 1&2) of the global WRR product of the G.H. Lim (Seoul National University) Affiliation IRPI- CNR data-scarce regions in not eliminated. EU Earth2observe project. Each product A front is one of most important part Co-authors Given three collocated datasets (a triplet) includes a multi-model ensemble output. of weather and climate over East Asia, Wade Crow (USDA – Hydrology of precipitation, Triple Collocation (TC) The final ensemble output, considering bringing severe weather events such and Remote Sensing Laboratory, offers a valid alternative to characterize all products, incorporates differences in as heavy rain, damaging winds. We Beltsville, Maryland), Luca Brocca rainfall product errors without relying on forcing, model space/time resolutions have tried to recognize a front given (IRPI-CNR, Perugia, Italy) ground-based observations, but TC is and assimilation procedures used in each subject to several assumptions such as horizontally gridded variables on a Precipitation is a fundamental physical WRR product. specific pressure level through an the existence of an uncorrelated error process of the global hydrological between the products of the triplet – a Thus, evaluation of the ensemble output automated computer algorithm. Then, cycle, and its temporal and spatial requirement that is hardly satisfied within with respect to available long-term we have applied our approach to state- distribution has a significant impact global non-gauge based precipitation hydrologic observations for rainfall, of-the-art reanalyses; ERA-Interim, CFS, on many land applications. Acquiring estimates. streamflow and groundwater levels and MERRA. We have analyzed the result accurate and real-time precipitation data allows us to assess the accuracy of from front recognition to get statistics is essential to researching the global Recently, Brocca et al. (2014) developed current WRR products and the range of of front frequencies and front intensities hydrological cycle, mitigating worldwide a method for estimating rainfall from associated uncertainty due to differences (defined by precipitation rate, upward drought and flooding, simulating land satellite soil moisture observations in forcing and model structure. Bias wind, horizontal temperature gradient, surface hydrological processes, and based on the principle that the soil can and uncertainty characteristics are convective instability and so on) and understanding global climate change. be treated as a “natural raingauge”. presented as function of hydrologic compared it across the reanalyses. We In contrast with classical satellite variables and temporal scale (monthly, will try to elaborate possible explanation Despite this importance, ground- precipitation products, this new bottom- seasonal and annual). Results from this to a reason why the differences among based estimates of rainfall over land up approach attempts to measure rainfall analysis highlight the current strengths the reanalyses exist. are scarce within Africa, Central Asia by calculating the difference between and limitations of available WRR datasets and South America hence, relying on two successive SM measurements for analyzing the hydrological cycle these estimates for studying processes derived from a satellite sensor. and dynamics of East Africa region and at large scales is often impossible. provide unprecedented information for Satellite and reanalysis rainfall products both developers and end users in similar offer a valid alternative to ground based hydroclimatic regimes. observations but are subjected to some limitations that depend on the type of precipitation, topography and type of the background surface (Ebert et al. 2007)
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 93 Section 4
index has been derived from different and wavelet coherence. The period for Medium-Range Weather Forecasts’ Historical Southern Annular reanalysis, but it was affected by bias considered was 1905-2005. We found a (ECMWF) ERA-Interim reanalysis, 2) the Mode index derived from 20th of pressure values at high southern good agreement among all indices and a Monitoring Atmospheric Composition Century reanalysis and ERA- latitudes. Due to these reasons, SAM see-saw pattern adequately captured by and Climate (MACC) reanalysis and 20C: an overview index derived by Marshall (based both reanalyses after 1957. Before 1957, a 3) NASA’s Modern-Era Retrospective on appropriately located station weaker see-saw pattern was reflected at Analysis for Research and Applications Author Mariana Barrucand observations) is considered in many both reanalyses, slight better represented Version-2 (MERRA-2) reanalysis. Affiliation Conicet/University climate studies, but it is only available with 20CR. The results provide valuable The ERA-Interim cyclone tracks are of Buenos Aires since 1957. In order to understand how information for climate studies linked to used here to establish the long-term decadal to interdecadal hemispheric middle and high latitudes of the Southern relationship between cyclones and ozone Co-authors and regional processes have evolved Hemisphere. observations (since 1988). M. E. Zitto (Facultad de Ingeniería, over time, long time climate indices are Universidad de Buenos Aires, Buenos The MACC reanalysis data set, which needed, but the limitations originated Aires, Argentina), R. Piotrkowski (Facultad covers the period 2003–2012, is by the lack of data in the first part of Influence of mid-latitude de Ingeniería, Universidad de Buenos produced with the ECMWF integrated 20th Century must be taken into account. cyclones on European Aires, Buenos Aires, Argentina. Escuela forecast system (IFS) model two-way 20th Century Reanalysis (NOAA-CIRES) background surface ozone de Ciencia y Tecnología, Universidad coupled to a chemistry transport model and ERA-20C (ECMWF) provide datasets Nacional de San Martín, San Martín, Prov. investigated in observations (CTM). Since the MACC reanalysis uses spanning the entire twentieth century. de Buenos Aires, Argentina), P. Canziani and multiple reanalyses a similar atmospheric model to ERA- (Unidad de Investigación y Desarrollo de In this work, these datasets were Author Katherine Emma Interim, MACC is used to explore the las Ingenierías, Facultad Regional Buenos considered in order to construct Knowland mechanisms within case study cyclones Aires, Universidad Tecnológica Nacional, “Historical” SAM indices using sea that can influence surface ozone Universities Space Consejo Nacional de Investigaciones level pressure (SLP) values of 20CR Affiliation concentrations at Mace Head and Monte Research Association Científicas y Técnicas CONICET, (SAM20) and ERA-20C (SAMERA20) Velho. (USRA) / GESTAR & Buenos Aires, Argentina) according to Gong and Wang definition NASA GMAO The MERRA-2 reanalysis also provides (normalized differences of SLP between With the aim of understanding climate 3D distributions of ozone, although 45°S and 60°S). Likewise, other indices Co-authors processes while managing large less ideal for analysis of surface ozone were constructed, only considering the R.M. Doherty (School of Geosciences, datasets and model outputs for climate concentrations since MERRA-2 ozone grid points in the vicinity of the surface University of Edinburgh, Edinburgh, UK), variability and change studies, it is often under represents ozone variability in the stations used by Marshall (SAM20M K.I. Hodges (Department of Meteorology, convenient to define climate indices. lower troposphere as MERRA-2 has a and SAMERA20M respectively) with the University of Reading, Reading, UK), These are based on physical principles less detailed chemistry and emissions aim to perform a comparison with the L.E. Ott (NASA/GMAO) and statistical methods and they can scheme for the troposphere compared to observational index. be derived from observations or from The relationship between springtime mid- the MACC reanalysis. reanalysis products. A SAM index derived with other latitude cyclones and background ozone However, the MERRA-2 reanalysis has methodology (EOF) was also taken into at two rural monitoring sites on the west One climate index of special interest at the potential to identify more features account (AAO 0). All these indices were coast of Europe – Mace Head, Ireland Southern Hemisphere is the Southern 2 within the cyclones as the resolution is analyzed and compared on a range of and Monte Velho, Portugal – is explored Annular Mode (SAM), the principal higher than the MACC reanalysis, and timescales by spatial patterns analysis, using a combination of observations and mode of variability of the atmospheric correlation analysis, wavelet transform three reanalyses: 1) the European Centre circulation in the SH extratropics. This
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 94 Section 4 therefore is used in conjunction with the and relative humidity over China between consistence of annual variability and Satellite based products perform MACC reanalysis to provide a measure of radiosonde and the third generation dispersion in the lower troposphere reasonably well within tropical forests uncertainty to the case study analysis. reanalysis was undertaken. between REA and ADJ, and the and Eastern Asia and North America dispersion of REA were obviously higher but are subjected to errors at northern We found the main source of high The relative difference, correlation, than ADJ in the middle and upper latitudes. SM2RAINasc performs better ozone to these two sites is from the standard deviation and linear trend troposphere. in the Southern Hemisphere in areas stratosphere, which is well represented during 1979–2015 derived by RAW, ADJ where neither ERA-Interim nor the in both the MERRA-2 reanalysis and and REA were analyzed. The linear trends of specific humidity are satellite-based datasets provide good the MACC reanalysis, and occurs either consistent between REA and ADJ with The results revealed significant results. from direct injection into the cyclone wetting trends in the lower troposphere discontinuities in the raw radiosonde or associated with aged airstreams while different in the middle troposphere specific humidity and relative from decaying cyclones that becomes with wetting trends from ADJ and drying humidity time series in China and the IIntercomparison of regional and entrained and descends towards the trends from REA. The linear trends of homogenization of original data is global oceanic reanalyses in the surface within new cyclones over the relative humidity in the troposphere were essential for reanalysis assessment. Mediterranean Sea region. obviously different between REA and Homogenization adjusted the RAW with ADJ with drying trends from REA while Author Jonathan Beuvier a substantial correction before 2000s. wetting trends and more significant The average specific humidity and Affiliation Mercator Océan Inter-comparison of upper air wetting in the middle and upper relative humidity over China from REA Co-authors water vapor over China between troposphere. The spatial distribution were generally wetter than those from M. Hamon (Mercator Océan), Radiosonde and the third of trends from ADJ at 118 stations and radiosonde and the differences of relative C. Desportes (Mercator Océan), REA at the corresponding grids showed generation Reanalysis Datasets humidity were higher than specific M. Drévillon (Mercator Océan), remarkable difference over China. Author Zhang Siqi humidity. J.-M. Lellouche (Mercator Océan), In this contest, SM2RAIN offers an Y. Drillet (Mercator Océan) Affiliation National Climate Center Meanwhile the differences in the upper additional non-gauge based dataset for troposphere were larger than those in the One of the objectives of the COST action Co-authors properly applying TC on a global scale In lower troposphere, and the differences “Evaluation of Ocean Syntheses” (see Guo Yanjun (National Climate Center, this study, TC analysis has been applied between REA and ADJ were more presentation by Alvera-Azcárate et al.) Beijing 100081, China), Wang Guofu to the rainfall estimates derived from 1) remarkable than the difference between is to foster regional ocean reanalyses (National Climate Center, Beijing 100081, ERA-Interim, 2) SM2RAIN via inversion REA and RAW. The differences in spring intercomparisons, which focus on the China) of Advanced SCATterometer (ASCAT), and autumn were more significant than evaluation of specific regional processes SM2RAINasc, 3) the NOAA Climate Based on quality controlled (RAW) and those in summer. The consistency of and variability, in particular in ocean Prediction Center morphing (CMORPH) homogenized (ADJ) radiosonde data specific humidity and relative humidity and climate variability “choke points” and 4) the TRMM Multi-satellite from 118 stations in China and monthly from four reanalysis is high and JRA-55 such as the Mediterranean Sea. An Precipitation Analysis (TMPA 3B42RT) in mean specific humidity and relative were relative similar with radiosonde intercomparison in the Mediterranean the period 2007-2012. We found that that humidity from four reanalysis datasets with dryer humidity than other three Sea, also considering global ocean ERA-Interim dataset performs relatively (REA) which included ERA-Interim, reanalysis. reanalyses, will take place in 2017-2018. JRA55, MERRA and CFSR, a preliminary well in the Northern Hemisphere while comparison of upper air specific humidity The correlation and standard deviation have some limitations in Africa and South In this context, we show preliminary ratio of specific humidity and relative America. results of the evaluation of the humidity demonstrated the higher functioning of the Mediterranean Sea
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 95 Section 4
(water masses properties, transports Homogenization removed system error through the Strait of Gibraltar, oceanic Intercomparison of Upper Air caused by radiosonde instrument change Interdecadal variation of deep convection) for both global Temperature over China and updates to the radiation adjustment atmospheric overturning (GLORYS, Ferry et al. 2012) and regional between Radiosonde and method and observation system of RAW. circulation in the ERA-20C (MEDRYS, Hamon et al. 2016) reanalyses. Multiple Reanalysis Datasets Hence, the correlation between REA and reanalysis Global products have a too high water ADJ was higher than that between REA transports through the Strait of Gibraltar Author Yanjun Guo and RAW. The mean difference between Author Bo Dong (both in free runs and in assimilated runs), Affiliation National Climate Center/ REA and ADJ was approximately 1°C Affiliation University of Reading leading to a negative net salt transport China Meteorogical during 1981–2010, while REA was mostly for the Mediterranean Sea in long-term Administration cooler than ADJ in the troposphere and The phase transition of the Interdecadal average (opposite to what is observed), warmer in the stratosphere. Significant Pacific Oscillation (IPO) is one possible Co-authors and also to an important decrease of the correlation demonstrated the consistency cause of the early 2000 global warming Siqi Zhang (NCC, CMA), Jinghui Yan salinity of the surface layer (0-150m). The between the annual variability of REA hiatus. To physically understand the (NCC, CMA), Zhe Chen (National intermediate layer (150-600m) is too high and ADJ. modulation, changes in atmospheric Meteorological Information Center and too fresh in the free runs. Moreover, overturning circulations and the NMIC, CMA), Xin Ruan (NMIC, CMA) The linear trends were consistent the deep layers (below 600m) display an associated energy transport for the IPO between REA and ADJ, with warming unrealistic interannual variability, both Based on quality controlled (RAW) and global warming (GW) are quantified in the lower and middle troposphere in temperature and salinity, before year and homogenized (ADJ) radiosonde and contrasted using the ERA-20C and cooling in the middle stratosphere. 2005 and the substantial deployment of temperatures at 10 pressure levels from reanalysis data. Greater uncertainty was apparent the Argo network in the Mediterranean. 118 stations across China, and monthly for the upper troposphere and lower Multiple linear regression analyses For the deep convection, a focus is mean temperatures from 8 reanalysis stratosphere. ERA-Interim, JRA55 show that both warm IPO and GW made on winter 2013 in the Gulf of Lion, datasets (REA) including NCEP-1, and MERRA were generally closer to modes feature significant weakening to benefit from the oceanic Special NCEP-2, ERA-40, ERA-Interim, JRA-55, homogenized radiosonde temperatures and eastward shift of the Pacific Observation Period of the HyMeX 20CR, MERRA and CFSR, a preliminary than the other reanalysis datasets. Walker circulation, and strengthening program (Estournel et al. 2016). comparison of upper air temperature of the Hadley circulation, characterized over China between radiosonde and by southward shift of the ITCZ and reanalysis data was undertaken. intensified deep tropical convection The mean difference, correlation, with contracted meridional extent. Also, standard deviation and linear trend of strengthening in the subtropical jet, upper air temperature based on original increases in tropospheric temperature and homogenized radiosonde and and humidity are found. reanalysis temperature during 1981–2010 The resemblance of the two trend modes were analyzed. Generally, homogenized indicates that circulation anomalies temperatures averaged over China were of warm (cold) IPO phases amplify cooler than RAW, and the negative (dampen) the anthropogenic warming- adjustment in the upper troposphere and induced circulation trends. Besides, a lower stratosphere was more significant few implausible circulation trend patterns than in other layers. are found in the GW mode, such as
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 96 Section 4 strong increases in the tropospheric These OMIs have been operationally temperature over the Antarctic, and Monitoring and long-term implemented starting from the physical Multidecadal Rainfall Variability decreases in atmospheric humidity in assessment of the reanalysis products and then they have in Sahel the northern extratropics. The causes of been applied to the operational analyses. Mediterranean Sea physical Author Ellen Berntell these spurious changes in the ERA-20C state Sea surface temperature, salinity, height reanalysis deserve further investigation. as well as heat, water and momentum Affiliation Department of Author Simona Simoncelli fluxes at the air-sea interface have been Meteorology, Stockholm operationally implemented since the University Long-term trends in the Affiliation Istituto Nazionale di Geofisica e Vulcanologia reanalysis system development as a real stratosphere using reanalyses time monitoring of the data production. The Sahel is a water vulnerable region Co-authors which exhibits strong inter-annual rainfall Author Michal Kozubek Claudia Fratianni (INGV), Emanuela Their consistency analysis against variability. During the 20th century the Affiliation Institute of Atmospheric Clementi (INGV), Massimiliano Drudi available observational products or Sahel region experienced extended dry Physic (INGV), Jenny Pistoia (INGV), Alessandro budget values recognized in literature periods and droughts, with devastating Grandi (INGV), Damiano Del Rosso guarantees the high quality of the effects on the livelihoods of the people in The long-term trend of different (INGV), Andrea Storto (CMCC) numerical dataset. The results of the region. In this study the multidecadal atmospheric parameters has been studied the reanalysis validation procedures The near real time monitoring and long- variability of Sahel precipitation is separately during previous years in many are yearly published in the QUality term assessment of the physical state examined in the gridded observational papers. This study is focused on the Information Document since 2014 of the ocean are crucial for the wide dataset CRU and in the 20th-century temperature, wind (u and v component), available through the CMEMS catalogue CMEMS user community providing a reanalysis ERA20C. geopotential height and watervapour (http://marine.copernicus.eu), together continuous and up to date overview trends during 1979-2016. We present with the yearly dataset extension. Additionally, we use the Hadley sea the trend for each month with respect to of key indicators computed from surface temperature and sea level ozone turnaround during mid 1990s. operational analysis and reanalysis New OMIs of the winter mixed layer pressure datasets and the coupled datasets. depth and the heat content will be reanalysis CERA20C. Our analysis of The different reanalyses (MERRA, presented, in particular we will analyze This constitutes an operational warning the Sahel (10−18N, 20W -30E) July- ERA-Interim, JRA-55 and NCEP-NOE) their time evolution and trends starting system for the advanced prediction of September rainfall using CRU shows are used for comparison. We analyzed from 1987. Consistency analysis between extreme events, stimulating the research a clear multidecadal variability with a every grid point to reduce the problem OMIs computed from global, regional towards a deeper understanding of them dominating period of 60-80 years and a with zonal averages indifferent pressure reanalysis and analyses datasets will be and consequently increasing CMEMS high correlation to the North Atlantic sea levels. The results will show the shown as well. At the end, the focus will products uptake. Ocean Monitoring surface temperatures on a multidecadal complex view on the trend in the middle be on 2016 sea state and circulation of Indicators (OMIs) of some Essential scale. atmosphere (troposphere, stratosphere the Mediterranean Sea and its anomaly Ocean Variables have been identified and lower mesosphere). with respect to the climatological fields to Using a global field correlation and a and developed by the Mediterranean detect the 2016 peculiarities. single value decomposition we could This comparison can give us the clue Monitoring and Forecasting Centre see that the highest correlation between which reanalysis is better for studying (MED-MFC) under the umbrella of the low-pass filtered Sahel rainfall and sea different phenomena (QBO, NAO, ENSO, CMEMS MYPWG (Multy Year Products surface temperatures was located in etc.) and which one has some issues. Working Group). the mid-latitudes and in the sub-polar region as well as in eastern North
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 97 Section 4
Atlantic with values around R = 0.8. understanding of the climate as they correcting the mean state causes the Similarly, ERA20C reanalysis dataset Observation feedback confront observations with model in a deceleration of the warming trend and exhibits multidecadal rainfall variability in information of the ECMWF consistent and systematic way. alters the long-term climate signal. The Sahel with a dominating period of 60- ensemble spread reflects the long-lasting coupled climate reanalysis This presentation will describe 80 years, however largely out of phase memory of the initial conditions and the assessment results of CERA-20C such with the observational dataset and with Author Yuki Kosaka convergence of the system to a solution as trends of the analysis field and quality no correlation to the North Atlantic sea Affiliation JMA/ECMWF compatible with surface fluxes, ocean of the observations. surface temperatures. Co-authors model and observational constraint. The composite analysis of low-pass Patrick Laloyaux (ECMWF), Eric de Observations constrain the ocean heat filtered data showed a clear increase of Boisseson (ECMWF), Per Dahlgren Ocean heat content variability uptake trend of the last decades of rainfall across Sahel in wet compared to (ECMWF), Dinand Schepers (ECMWF) in an ensemble of 20th century the 20th century, which is similar to dry years for both the CRU observational The European Centre for Medium- ocean reanalyses estimations from the post-satellite era. and ERA20C reanalysis datasets. The An ocean heat budget analysis attributes Range Weather Forecasts (ECMWF) Author Eric de Boisseson composite difference for the sea level has developed a coupled assimilation ORA-20C heat content changes to Affiliation ECMWF pressure and surface temperature system that ingests simultaneously surface fluxes in the first part of the suggest that a strengthening of the ocean and atmospheric observations in Co-authors century. The heat flux variability reflects thermally driven meridional pressure a coupled ocean-atmospheric model. M. Balmaeda (ECMWF) and M. Mayer spurious signals stemming from ERA- gradient between Sahara and the Coast This approach has been used to produce (University of Vienna/ECMWF) 20C surface fields, which in return of Guinea in wet compared to dry result from changes in the atmospheric a new coupled 20th-century reanalysis, In the context of the EU-funded ERA- years is the driving mechanism for the observing system. called CERA-20C, which provides a CLIM2 project, ECMWF produced a ten- multidecadal rainfall variability in Sahel long record of low-frequency climate member ensemble of 20th century Ocean The influence of the temperature for both the observational and reanalysis variability using a consistent set of ReAnalyses called ORA-20C. ORA-20C assimilation increments on the heat dataset. observations. assimilates temperature and salinity budget is growing with time. Increments The strengthened gradients both To account for errors in the observational profiles and is forced by the ECMWF control the most recent ocean heat increase the moisture in the region record as well as model error, CERA- 20th century atmospheric reanalysis uptake signals, highlighting imbalances in through increased moisture flux and 20C provides a 10-member ensemble (ERA-20C) over the 1900-2010 period. forced reanalysis systems as well in the intensifies the monsoon system through of reanalyses. Regarding observation This study attempts to identify robust ocean as in the atmosphere. strengthened monsoon winds, resulting data, surface pressure and marine signals of ocean heat content change in in increased rainfall. The study shows wind observations as well as ocean ORA-20C and detect contamination by that it is challenging to capture the temperature and salinity profiles are model errors, initial condition uncertainty, multidecadal Sahel rainfall variability in assimilated in the CERA-20C assimilation surface fluxes and observing system reanalysis data. Reasons for this behavior system. changes. are discussed and the behaviour of the It is shown that ORA-20C trends and Sahel precipitation is also analyzed for These observation data, as well as variability in the first part of the century CERA20C. model departures before and after assimilation and usage flags, are stored result from the surface fluxes and model in observation feedback archive files. drift towards warmer mean state and These files can be used to improve our weak meridional overturning circulation. The impact of the observing system in
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 98 Section 4
positive polarity, indicative of antarctic The radiosonde and marine weather Performance evaluation of ozone depletion and Green House observations captured detailed time Planetary boundary layer CMIP5‘s characterisation of Gases induced warming of sea surface variations and vertical structures depicted by most recent regional circulation over Southern Africa temperatures. All these kinematic of temperature, wind and humidity reanalyses and its adjacent oceans using properties of circulation elements associated with the Beaufort High, observed in the reanalyses are used synoptic-scale cyclone, polar low and Author Ronny Petrik reanalyses. as a benchmark to evaluate the CMIP5 seasonal change. Affiliation Helmholtz Centre models’ performance in reproducing Geesthacht Institute for Author Teboho Nchaba While 4 atmospheric reanalyses (ERA- them. Evaluating the performance of Coastal Research Affiliation University of Cape Town Interim, CFSv2, MERRA, JRA-25) and the historical runs of the CMIP5 models initial values of the forecast from 8 Co-authors Co-authors allows for models’ selection and provides weather centers around the world from Beate Geyer (Helmholtz-Zentrum C Lennard (Climate System Analysis a baseline for analysing their projections. Group, University of Cape Town), the TIGGE (THORPEX Interactive Grand Geesthacht, Institute for Coastal Global Ensemble), roughly reproduced Research), Burkhardt Rockel (Helmholtz- The third generation reanalyses, the Performance of objective the above characteristics, there were Zentrum Geesthacht, Institute for Coastal CFSR, MERRA-2, and ERA-Interim, some differences. Research) are used in this study to evaluate the analysis data over the Pacific performance of the Coupled Model Arctic Ocean in summer based Compared to the observation, the large “Within the framework of the project Intercomparison Project Phase 5 on meteorological observations differences were seen in the temperature openFRED feed in power within complex (CMIP5) historical runs in characterizing during the R/V “Mirai” Arctic near the boundary layer and tropopause, electricity grids are simulated with energy system models over a couple of years. atmospheric circulation over Southern cruises wind speed in the whole troposphere and Africa and its adjacent oceans. The water vapor in the lower troposphere. The energy system models require to evaluation is performed for austral Author Kazuhiro Oshima have input data for the energy production The spread among the datasets were of each single renewable power plant. summers during the satellite era between Affiliation Japan Agency for also large for those variables. It is One of the possibilities is to rely on the 1980 and 2004. Reanalyses show Marine-Earth Science likely that the discrepancies are due data from regional hindcasts, because decreases in near surface wind speeds, and Technology to different treatments of snow/ice they allow to get a detailed picture of at 850 hPa and 10-m above ground level, Co-authors processes and of vertical resolution over the South East Atlantic and west the atmospheric processes during the M. E. Hori (JAMSTEC), Y. Kawai among the models using for the datasets. last decades. This details can still not coast of Southern Africa over the study (JAMSTEC), K. Sato (NIPR), period. be provided by the global reanalysis J. Inoue (NIPR) products as ERA, NCEP or MERRA. These changes in speeds are associated We evaluated the performance of However, the main question arises how with changes in the intensity of and a objective analysis datasets over the suitable are the regional hindcasts for poleward migration of the South Atlantic Pacific Arctic Ocean, the Chukuchi and the application with energy system Anticyclone, the midlatitude westerlies, Bering Seas based on meteorological modelling. the storm tracks and the descending limb observations during the R/V Mirai Arctic of the Hardly Cell. Our main focus is on the simulation cruises in the summer of 2013, 2014 and of feedin power with respect to solar The Southern Annular Mode indices 2015. plants, wind turbines and hydroelectric extracted from the reanalyses also power stations. As a first step, we show an inclination towards their aim at investigating the performance
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 99 Section 4 of various hindcasts with respect to The ARCGATE estimates (currently the representation of the planetary Precipitation over monsoon Asia: Reanalysis-based volume-, available October 2004 to May 2010) are boundary layer (PBL), i.e. how well the a comparison of reanalyses and temperature- and freshwater derived from mooring data in the four thermo- and hydrodynamic state of the observations transports through arctic straits under the constraint of mass-, PBL is captured by the models. Our gateways vs. mooring-derived and salinity conservation and include study involves, on the one side, regional Author Andrea Toreti realistic assumptions about freshwater hindcasts utilizing state-of-the-art/superb Affiliation European Commission, estimates input. We compare these new and data assimilation to force the model to Joint Research Centre Author Sebastian Stichelberger largely independent flux estimates (i.e. observations. Thanks to the UERRA Co-authors Affiliation University of Vienna most ARCGATE observations have not project most recently reanalyses were A. Ceglar (European Commission been assimilated in the reanalysis) to performed over Europe and provided Co-authors data of the Centro Euro-Mediterraneo Joint Research Centre), G. Balsamo M. Pietschnig (University of Vienna, by various European meteorological (European Centre for Medium-Range sui Cambiamenti Climatici Global services (for instance the COSMO- Department of Meteorology and Ocean Reanalysis System “C-GLORS, Weather Forecasts), S. Kobayashi Geophysics, Vienna, Austria), M. Mayer REA6 product by the DWD). On the (Japan Meteorological Agency) Version 5” and the latest ECMWF other side, our study involves regional (University of Vienna, Department Ocean Reanalysis System “ORAS5”. We hindcasts based on downscaling global Reanalyses represent an essential source of Meteorology and Geophysics, Vienna, investigate the differences between the reanalyses (as done for example at the of information for impact modelling Austria), T. Tsubouchi (Alfred Wegener datasets by preparing Hovmoeller plots Helmholz-Zentrum in Geesthacht).In the and monitoring in areas of the world Institute, Climate Sciences – Physical of volume-, temperature- and freshwater presentation we address the problem of characterised by sparse observational Oceanography of the Polar Seas, transports. finding evaluation data independent in network and/or limited data access. This Bremerhaven, Germany), A. Storto Generally, the patterns agree qualitatively the sense of a data assimilation process. study focuses on Monsoon Asia, a key (Centro Euro-Mediterraneo sui at most locations. An exception are The evaluation of the daily cycle of the agricultural region of the world. Cambiamenti Climatici, Ocean Modeling discrepancies in Davis Strait transports PBL is shown as well as the performance and Data Assimilation Division, Bologna, Four reanalyses (ERA-Interim, ERA- at the West Greenland slope region, with respect to the timing of specific Italy), H. Zuo (ECMWF, Reading, United Interim Land, AgMerra and JRA-55) are where upper-ocean volume transports lower-tropospheric weather events. Kingdom), L. Haimberger (University analysed and compared with two gridded are northward in ARCGATE throughout Moreover, it is discussed whether and of Vienna, Department of Meteorology observational datasets: Aphrodite and the year whereas they are northward only how far the reanalysis products are and Geophysics, Vienna, Austria) Chirps. Seasonality, extremes and during the spring season in C-GLORS superior over the “simple” downscaling distributional differences are assessed by Recently, new estimates of volume-, and during the spring and summer products.” using a combination of recently proposed temperature and freshwater transports season in ORAS5. statistical methods. The main results into the Arctic Ocean through the four show the good performance of the major gateways (Davis-, Fram-, and Comparing time series of total volume-, bias-corrected reanalysis AgMerra, the Bering Strait and the Barents Sea temperature- and freshwater transports temporal homogeneity of JRA-55 and the Opening) have become available through through each strait from ARCGATE good spatial representation provided by the ARCGATE project (“Maximizing the against the C-GLORS and ORAS5 data ERA-Interim Land. potential of the Arctic Ocean Gateway we find good quantitative agreement array”). for both reanalyses only in Fram Strait volume-, and in Bering Strait temperature transports.
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Considerable disagreement is found for the impact of the atmospheric forcing based on 250 hPa stream function the other straits and transport types, appears only marginal for the global heat South America climatic impact data, over South Pacific and a center which must be investigated further. The content estimates in both upper and during PDO phases based on of action on the southeastern South net export of volume out of the Arctic deeper oceans. NCEP-NCAR reanalysis I, JRA55 America, JRA55 shows only reversal Ocean derived from ARCGATE is – signs over South Pacific, from tropical A sensitivity assessment performed and ERA40 0.15 ± 0.06 Sv. This value is matched to middle latitudes. Considering the through realistic perturbation of the by ORAS5 very well (- 0.14 ± 0.18 Sv), Author Maria Elisa Siqueira Silva original values, NCEP-NCAR reanalysis main sources of uncertainty in ocean while C-GLORS net volume export I shows the strongest anomalous signs reanalyses highlights that bias- Affiliation Univerty of São Paulo is only about one third of the ARCGATE in the three PDO phases for both wind correction and pre-processing of in- Co-author estimate (- 0.05 ± 0.22 Sv). and geopotential height, while JRA55 situ observations represent the most Carlos Batista Silva shows the weakest anomalies. Beside crucial component of the reanalysis, The South America climatic behavior the anomaly intensity, the position of the whose perturbation accounts for up to Sensitivity of ocean heat on reversal Pacific Decadal Oscillation, strongest anomalies changes accordingly 60% of the ocean heat content anomaly content from reanalyses to the PDO, phases, from 1970 to 2003, is the reanalysis dataset. variability in the pre-Argo period. atmospheric reanalysis forcing: analyzed in this study through composite In all the three PDO phases, JRA55 zonal These results reveal useful information anomaly fields and the EOF technic. We a comparative study wind anomalies at low levels show a for the ocean observation community used the reanalysis I of NCEP-NCAR, westward displacement of the strongest Author Andrea Storto and for the optimal generation of ERA40 and JRA55 reanalysis datasets. negative and positive sign placed at the Affiliation CMCC perturbations in ocean ensemble Considering geopotential height and northern South America in relation to the systems. Additional information on the wind variables, at low and high levels, Co-authors NCEP-NCAR and the ERA40 reanalysis. dependence of the quality of ocean all the three datasets present reversal C Yang (CNR-ISAC), S Masina Also, the opposite sign placed over the reanalyses from atmospheric products climatic patterns on distinct PDO phases equatorial eastern Pacific westward of The global ocean heat content evolution are also presented. (1970-1976, 1977-1996, 1997-2003), with the strongest anomaly observed in the is a key component of the Earth’s different intensities. energy budget and can be accurately NCEP-NCAR and ERA40 datasets of determined by ocean reanalyses that Although the three first EOF modes the low level zonal wind anomaly in the assimilate hydrographic profiles. This obtained from the 850 hPa stream northern South America is not observed work investigates the impact of the function show very similar spatial in the JRA55 data. patterns over South Pacific and South atmospheric reanalysis forcing through a This aspect in the low level zonal wind America in the three considered multi-forcing ensemble ocean reanalysis, anomaly is observed both for positive reanalysis, it is possible to notice where the ensemble members are forced and negative PDO phases, constituting some important differences among by five state-of-the-art atmospheric an important distinction since it is the original values. At 250 hPa, NCEP- reanalyses during the meteorological observed throughout the whole analysed NCAR reanalysis I and ERA40 stream satellite era (1979-2013). period. function 3rd EOF modes agree very well Data assimilation leads the ensemble while JRA55 presents great differences to converge towards robust ocean heat in relation to these other two datasets. content estimates and significantly While NCEP-NCAR reanalysis I and reduces the spread (1.48 +/- 0.18 W/m2, ERA40 3rd EOF modes show a well per unit area of the World Ocean); hence characterized mean wave train pattern,
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 101 Section 4
products cover large parts of the NH, the observed trends and not with those Spring snow albedo feedback in but have problems with large solar zenith Stratospheric trends: Reanalysis from climate models (e.g. Monge-Sanz daily data over Russia. Analyzing angles as well as over complex terrain v. climate models et al., 2012; Diallo et al., 2012; Ploeger et in-situ data in comparison with (eg. Wang et al. 2014). al., 2015). To increase our confidence in Author Beatriz Monge-Sanz climate-chemistry projections, the causes reanalyses Our analysis focuses at the Russian Affiliation ECMWF for the apparent disagreement in trends territory where we utilize in-situ radiation Author Martin Wegmann of age-of-air between observations and and snow depth measurements. We Co-authors most climate models need to be identified. Affiliation University of Grenoble found 50 stations which measure both D. Dee (ECMWF), H. Hersbach (ECMWF), Co-authors variables on a daily basis for the period A. Simmons (ECMWF), J. A. Parodi When evaluating different reanalysis O. Zolina (Institut des Géosciences de 2000-2013. Since Hall (2004) found (AEMET), P. Hitchcock (NCAR), F. Haenel products it is important to know, to the l’Environnement, University of Grenoble, that 50% of the notal NH snow albedo (KIT), G. Stiller (KIT), M. P. Chipperfield possible extent, what differences among Grenoble, France and P.P. Shirshov feedback caused by global warming (U. Leeds), W. Feng (U. Leeds) datasets are due to the differences in the Institute of Oceanology, Moscow, Russia), occurs during NH spring, we focus on In the framework of the SPARC Reanalyses underlying numerical models, and what H.-W. Jacobi (Institut des Géosciences de the transition period of March to June Intercomparison Project (SRIP), we are differences are due to the assimilated l’Environnement, University of Grenoble, (MAMJ). Here we use custom ERA- evaluating the main reanalysis products datasets of observations. Grenoble, France), E. Dutra (Instituto Interim land configurations with different of the world (Fujiwara et al., 2017) with a That is why in this study we have carried Dom Luiz, Faculdade de Ciências, vegetation settings to compare in-situ particular focus on their ability to reproduce out simulations with a CTM to assess Universidade de Lisboa, Lisbon, Portugal) data to gridded products in respect to stratospheric processes. the stratospheric circulation with the albedo and snow depth properties on Global warming is enhanced at high ERA-Interim dataset, as well as with data daily and seasonal scales. In the present study we focus on the northern latitudes where the Arctic Brewer-Dobson circulation (BDC), produced from an equivalent climate surface air temperature has risen at We found a very good representation of the major circulation pattern in the system. AoA trends from our model twice the rate of the global average in daily snow variability and small absolute stratosphere. Most climate models results with ERA-Interim fields are in recent decades – a feature called Arctic errors among different reanalyses. have predicted an intensification of the good agreement with the recent age-of- amplification. This recent Arctic warming However, due to vegetation parameters, stratospheric circulation with the increase air studies based on observations and signal likely results from several factors albedo in reanalyses shows substantially in greenhouse gases concentrations, differ from the results we obtain with the such as the albedo feedback due to lower variability than in stations. For which translates into younger age- corresponding climate data. a diminishing cryosphere, enhanced this, significant improvement was of-air (AoA) values modelled in the We will show that biases in the mean AoA poleward atmospheric and oceanic heat found between stations and grass- stratosphere. Nevertheless, balloon and values are also different for these datasets transport, and changes in humidity. only configurations of ERA-Interim satellite observations do not agree with compared to observations. In addition we land. Finally, snow albedo feedbacks in Surface albedo feedback is stating that the widespread modelled trend towards have used recent experimental datasets stations and grass-only configurations the additional amount of shortwave younger age-of-air for the recent past from the ECMWF system to identify are naturally higher than in “realistic” radiation at the top of the atmosphere (Engel et al., 2009; Stiller et al., 2012; potential causes for the differences in AoA configurations of ERA-Interim. decreases with decreasing surface Haenel et al. 2015). distribution and trends. The validation of albedo whereas surface air temperature Furthermore, a few recent studies with our model results has been performed increases with decreasing surface chemistry transport models (CTMs) driven against the new revised AoA dataset albedo. Unfortunately, there remains a by ERA-Interim reanalysis (Dee et al., based on MIPAS SF6 observations lack of reliable observational data over 2011) have also shown agreement with (Haenel et al., 2015). large parts of the cryosphere. Satellite
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 102 Section 4
currently developed with that same This analysis shows that the assimilation The Copernicus Marine Service NEMO model grid (ORCA025 at 1/4°) to The effect of the data of surface fields apparently introduces Global Reanalysis Ensemble propose a multi-model ensemble product. assimilation on Hadley some spurious trends in the HC, Product GREPV1: deriving Four reanalyses are used; GLORYS2V4 Circulation variability and trends enhancing its multi-decadal and long- robustness estimates for ocean from Mercator Océan (Fr), ORAS5 from in the 20th century term variability. Its effect is particularly ECMWF, FOAM/GloSea from Met Office strong on Southern HC, where its currents and transports (UK), and C-GLORS from CMCC (It). The Author Roberta D’Agostino strengthening is only supported by Author Marie Drévillon four different time series of global ocean Affiliation Max Planck Institute ERA-20C and it is inconsistent with Affiliation Mercator Océan monthly estimates have been post- for Meteorology the projected weakening of the tropical processed to create the new product circulation. Assimilating surface Co-author Co-authors called GREP (Global Reanalysis Ensemble pressure and winds weakens the P. Lionello (University of Salento Clément Bricaud (Mercator Océan), Product), covering the recent period dynamical link between Southern HC and CMCC) Yann Drillet (Mercator Océan), Karina von during which altimetry observations are extent and meridional temperature Schuckmann (Mercator Océan), Gilles available: 1993-2015. The effect of the data assimilation gradient and extratropical tropopause Garric (Mercator Océan), Simona Masina on Hadley Circulation (HC) and ITCZ height in Southern Hemisphere, rising The ensemble mean and standard (CMCC), Andrea Storto (CMCC), Laura variability has been investigated through inconsistencies among ERA-20CM deviation of the ensemble, as well as the Jackson (UK Met Office), Drew Peterson the comparison of trend magnitudes and ERA-20C. Further, the analysis is four individual members for the period (UK Met Office), Richard Wood (UK Met among ERA-20CM and ERA-20C. ERA- extended to the ECMWF reanalysis ERA- 1993-2015, are thus made available on a Office), Hao Zuo (ECMWF), Magdalena 20CM is a 10-member atmospheric Interim, for the period 1979-2010, where 1°x1° grid and monthly frequency. The time Balmaseda (ECMWF), Stéphanie model integration forced by 10 different these correlations are found not to be series will be extended by one year each Guinehut (CLS), Sandrine Mulet (CLS), realisations of prescribed sea surface statistically significant. On this respect year. In this presentation, and in a series of Jérôme Gourrion (Coriolis), Laurent temperature (HadISST2.1) and sea-ice it appears that ERA-20CM produces a companion posters, the ensemble mean Parent (Mercator Océan), Charly Régnier cover. more consistent evolution of the HC than performance will be compared to that of the (Mercator Océan), Charles Desportes ERA-20C and data assimilation weakens individual members, with respect to satellite It is meant to provide a statistical (Mercator Océan) dynamical links that would otherwise be and in situ observations, and with 3D estimate of the climate evolution and a present in model simulations. During the MyOcean project, several temperature and salinity estimates deduced good description of the low-frequency high resolution (1/4° horizontal grid) ocean from observations with statistical methods. variability of the atmosphere during the reanalyses based on the NEMO numerical 20th century without assimilating any Surface currents, heat and mass ocean model and constrained by satellite atmospheric observations. ERA-20C is transports, western boundary currents observations and in situ T and S profiles, a deterministic reanalysis based on the variability, and tropical oceans variability were produced with different tunings and same atmospheric model of ERA-20CM (El Niño, Atlantic and Indian ocean dipoles) by different institutes, and were evaluated and forced by the same prescribed deduced from GREP will be shown in this jointly using common validation guidelines HadISST2.1 of the first member of the presentation. We will explore, following (Masina et al, 2015, DOI: 10.1007/s00382- ERA-20CM ensemble. Furthermore, it Xue et al (2017, DOI: 10.1007/s00382-017- 015-2728-5). assimilates marine surface winds and 3535-y), the possibility to use the spread surface and mean sea level pressure. The Copernicus Marine Environment in between individual members in order Monitoring Service CMEMS (marine. to highlight robust signals. copernicus.eu) now takes advantage of the diversity of ocean reanalyses
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 103 Section 4
The Rs from reanalyses have larger The GEWEX Data and Assessments free ocean scale the trend estimates The evaluations of surface uncertainties, because their cloud fields Panel (GDAP) has initiated the GEWEX among long-term data records were incident solar radiation among were based on the model’s simulations in water vapor assessment (G-VAP) which generally found to be significantly reanalyses, satellite retrievals the reanalysis systems. Finally, ground- has the major purpose to quantify the different. Maxima in standard deviation and ESMs based observations of Rs and CERES current state of the art in water vapour among the data records are found over, EBAF Rs have been used to evaluate products (upper tropospheric humidity, e.g., tropical rain forests. These and other Author Ma Qian simulations of global climate models. specific humidity and temperature noticeable regions coincide with maxima Affiliation BNU profiles as well as total column water in mean absolute differences among vapour) being constructed for climate trend estimates. Co-authors The GEWEX water vapor applications. Kaicun Wang (Beijing Normal University), assessment (G-VAP) – results These distinct features can be explained Martin Wild (Institute for Atmospheric from inter-comparisons In order to support GDAP and the with break points which manifest on and Climate Science) general climate analysis community regional scale and which typically do and stability analysis G-VAP intends to answer, among others, not appear in stability analysis relative to A best effort was made to collect the following questions:a) How large are ground-based observations. Results from ground-based measurements of Author Karsten Fennig the differences in observed temporal profile inter-comparisons will also been surface incident solar radiation (Rs). Affiliation Deutscher Wetterdienst changes in long-term data records of shown and exhibit, among others, that However, the distribution of observations Co-authors water vapour on global and regional the observed break points are not only a is still deficient on a global scale. Marc Schröder (DWD, Offenbach, scales?b) Are the differences in observed function of region but also of parameter. Alternatively, satellite Rs retrievals, which Germany), Maarit Lockhoff (DWD, temporal changes within uncertainty employ sophisticated atmospheric Offenbach, Germany), Lei Shi limits?c) What is the degree of radiative transfer models with satellite (NOAA/NESDIS/NCEI, Asheville, USA) homogeneity (break points) of each long- observations of cloud and aerosol term data record? A general overview parameters used as input, can provide A large variety of water vapour data of G-VAP will be given. The focus of globally gridded values of Rs. records is available to date. Without proper background information and the presentation will be on observed Two sets of satellite retrievals of Rs from understanding of the limitations of inconsistencies among long-term data CERES EBAF and GEWEX-SRB (WCRP/ available data records, these data may records (eleven TCWV data records and GEWEX Surface Radiation Budget), were be incorrectly utilised or misinterpreted. seven specific humidity and temperature compared with Rs values from ground- The overall goal of assessments of CDRs profile data records, six of which are based observations. Furthermore, is to conduct objective and independent based on reanalysis). two reanalyses from ERA-Interim and evaluations and inter-comparisons in The inconsistencies are observed by MERRA (Modern Era Retrospective order to point out strengths, differences inter-comparisons, comparisons to Analysis for Research and Applications) and limitations and, if possible, to in-situ observations and the stability were evaluated with ground-based provide reasons for them. The need for analysis. On basis of consistently applied observations. It shows that the CERES such assessments is part of the GCOS tools major differences in state-of-art EBAF Rs has a better comparison guidelines for the generation of data CDRs have been identified, documented with the ground-based observations products. and to a large extend explained. The among the latest satellite retrievals and results and the answers for TCWV are reanalyses. summarized as follows: On global ice-
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 104 Section 4
All correlations are stronger in the boreal reanalysis efforts and published 6-hour The importance of reanalysis The link between the tropical winter while in summer they become and monthly data in the Earth System monitoring: the example of ERA5 precipitation and Hadley not significant with bothψ N and ψS. In Grid Federation (ESGF). ERA-20C and in ERAInterim there is a circulation: comparing ECMWF The reanalysis data is presented in a Author Andras Horanyi correlation between total precipitation reanalysis ERA-20C and ERA- similar way as the CMIP3 and CMIP5 Affiliation ECMWF in the deep tropics and values of CE archives, using standardized Climate Interim to the AMIP-like and N, whereas the correlation with Co-authors ψ and Forecast (CF)-compliant variable experiment ERA-20CM NE and SE becomes not significant and P. Berrisford (ECMWF), G. Biavati names and consistent metadata. Along vanishes in boreal summer. Further, the (ECMWF), H. Hersbach (ECMWF), Author Ascanio Luigi Scambiati with easy access, CREATE’s processing J. Muñoz-Sabater (ECMWF), C. Peubey correlation between CE, NE, SE and the Affiliation Università del Salento and interface enable comparing multiple position of the precipitation maximum (ECMWF), R. Radu (ECMWF), I. Rozum reanalysis data sets with each other and Co-authors located near the Equator and north and (ECMWF), D. Schepers (ECMWF), with climate and weather model output. R. D’Agostino (MPI), P. Lionello south hemisphere precipitation minima, A. Simmons (ECMWF), C. Soci (ECMWF) The data is published one variable per (University of Salento, CMCC) respectively are investigated. In ERA- file on the native horizontal grid and in The ERA5 reanalysis (implemented by 20CM the correlations are significant This contribution investigates the vertical pressure levels. the Copernicus Climate Change Service only in the boreal winter, in ERA-20C the on behalf of the European Commission) reproduction of the link between intensity of zonally averaged tropical precipitation and correlations remains significative only for An ancillary project has produced a is in production at the European Centre the CE and SE and in ERAInterim only for similar product of the temperature, for Medium-Range Weather Forecasts Hadley Circulation (HC) width and intensity in ECMWF ERA-20C and ERAInterim the SE. All these outcomes suggest that salinity, and velocity fields for the major (ECMWF). The scientific validation of data assimilation reduces a dynamical ocean reanalyses. In addition to the the particular model version used is at seasonal scale. The reanalyses are compared to the ERA-20CM (AMIP- link that would otherwise be present in native grids, the ocean reanalyses are followed by the routine monitoring of the atmospheric circulation model also regridded to a common vertical and the production suites of the system. experiment) data. The HC monthly mean mass stream function ψ is computed and horizontal grid. The ESGF data interface The monitoring activity is focusing on is widely accepted throughout the the observation usage of the system as the HC Central Edge (CE), the Northern The NASA/NCCS Collaborative Edge (NE) and the Southern Edge (SE) are international climate research community compared to ERA-Interim and ECMWF Reanalysis Technical and provides a variety of tools for operations, the observation departures defined as the zero-crossing latitudes of ψ bulk, where ψ bulk is the average of ψ Environment access. Procedures for downloading, from the first guess and the analysis viewing, and manipulating the data will between 150 and 700 hPa. Author Gerald Potter and on the analysis increments and be demonstrated. differences as compared to other The strength of the HC is given by the Affiliation NASA/GFSFC reanalysis systems at ECMWF. maximum and minimum values of ψ Co-authors The presentation will provide a brief in the Northern Hemisphere (ψN) and L. E. M. Carriere (NASA/GSFC), overview of the monitoring tools used Southern Hemisphere (ψS), respectively. J.A. Hertz (NASA/GSFC) In ERA-20CM results show a large for ERA5 and an insight into how the In order to simplify access to monitoring activity is organised. Some correlation between the total precipitation in the belt 10°N – 10°S (deep tropics) multiple reanalyses, the NASA/NCCS examples will be shown focusing on Collaborative REanalysis Technical when monitoring proved to be essential and values of NE, SE, CE as well as with ψN, while correlation between the total Environment (CREATE) has repackaged to detect problems and deficiencies of selected fields from the world’s major the ERA5 production suites. precipitation and ψS is weaker.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 105 Section 4
and following the peak values. While land, the unglaciated terrestrial surface, The role of stratospheric Tropical Energy Variability in the model represents these variations and sea ice/ocean. An examination dynamics on the climate system MERRA-2 and M2AMIP in general, regional strengths and is conducted of contemporary global weaknesses can be identified. reanalyses of the ECMWF Interim project, in response to Antarctic ozone Author Michael G. Bosilovich trends: CMIP5 versus NASA MERRA, MERRA-2, JRA-55, and Affiliation NASA GSFC GMAO NOAA CFSR using available in situ data Reanalyses Understanding Arctic surface Co-author and assessments of the surface energy Author Chiara Cagnazzo F.R. Robertson (NASA MSFC) temperature differences in budget. Overly-simplistic representations Affiliation ISAC-CNR reanalyses of the Greenland Ice Sheet surface are Studies have shown the correlation and found to be associated with local warm Author Richard Cullather Co-authors connection of surface temperatures air temperature biases in winter. G. Rea (ISAC-CNR), F. Fierli (ISAC-CNR) across the globe, ocean and land, related Affiliation ESSIC/University of to Tropical SSTs especially El Niño. This Maryland at College Park A review of progress made in the In this work we analyze how CMIP5 development of the MERRA-2 land- climate variability greatly influences Co-authors models represent the stratospheric ice representation is presented. Large regional weather and hydroclimate B. Zhao (Global Modeling and dynamics and specifically the lower uncertainty is also found in temperatures extremes (e.g. drought and flood). In this Assimilation Office, NASA Goddard stratospheric cooling observed in over the Arctic tundra and boreal forest paper, we evaluate the relationship of Space Flight Center), C.A. Shuman summer since 1979 to 2001 over zone. But a key focus of temperature temperatures across the tropical oceans (Cryospheric Sciences Laboratory, NASA Antarctica, an important aspect differences for northern high latitudes and continents in MERRA-2, and also Goddard Space Flight Center, Greenbelt, associated the austral springtime ozone is the Arctic Ocean. Near-surface in a newly developed MERRA-2 AMIP Maryland), S.M.J. Nowicki (Cryospheric hole. We find that models with a well- air temperature differences over the ensemble simulation (M2AMIP). Sciences Laboratory, NASA Goddard resolved and a chemical representation Arctic Ocean are found to be related Space Flight Center, Greenbelt, Maryland) of the stratosphere better represent M2AMIP uses the same model and to discrepancies in sea ice and sea the lower stratospheric cooling, when spatial resolution as MERRA-2, Reanalyses in the Arctic are widely surface temperature boundary data, compared to reanalyses. producing the same output diagnostics used for model evaluation and for which are severely compromised in over 10 ensemble members. Composite However, there is a large range of trends understanding contemporary climate current reanalyses. Issues with the El Niño temperature data are compared among reanalysis data sets. Here we use change. Nevertheless, differences among modeled representation of sea ice cover with observations to evaluate the land/ reanalyses to estimate uncertainties in reanalyses in fundamental meteorological are an additional factor in reanalysis sea contrast, variations and phase the observed trends and we use models variables including surface air temperature trends. Differences in the relationship. The temperature variations to assess information about the quality of temperature are large. For example, the representation of the surface energy are related to surface heat fluxes and the reanalyses trends. 1980-2009 mean surface air temperature budget among the various reanalyses atmospheric temperatures and transport, for the north polar cap (70°N-90°N) are also reviewed. to identify the processes that lead to among global reanalyses span a range of the lagged redistribution of heat in the 2.4 K, which approximates the average tropics and beyond. warming trend from these reanalyses Discernable cloud, radiation and data over the 30-year period of 2.1 K. assimilation changes accompany the Understanding these differences requires onset of El Niño affecting continental evaluation over the three principal regions through the progression to surface domains of the Arctic: glaciated
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 106 Section 4
is the unprecedented reduction of In particular we assess changes in the Unprecedentedly weak Indonesian Throughflow (ITF) volume Using a multi-model ensemble of AMOC strength as observed by the Indonesian Throughflow during (-20%) and associated heat transport ocean reanalyses to understand RAPID array, changes in Atlantic ocean 2015/16 speeds up Tropical (-25%) during 2015/16. Although recent changes in the North heat content and changes in North Pacific heat recharge after El Niño weakening of the ITF is typical for El Niño Atlantic ocean. Atlantic convection. events, the amount of heat retained in the Author Michael Mayer Pacific by reduced ocean energy export Author Laura C. Jackson Validation of reanalysis against Affiliation ECMWF was exceptional during 2015/16 and Affiliation Met Office explains 83% of the found difference variability and trends of in situ Co-authors Co-authors in OHC changes. stations temperature time-series M.A. Balmaseda (ECMWF), C. Dubois (Mercator ), L.C. Allison L. Haimberger (Univ. Vienna) The reduction of the ITF transports was (Met Office), K.A. Peterson (Met Office) in the western half of Iran related to the observed strong warming The 2015/16 El Niño event exhibited peak The observational network around the Author Piero Lionello of the eastern Indian Ocean in recent sea surface temperature (SST) anomalies North Atlantic has improved significantly Affiliation University of Salento years, which enhanced anomalous sea similar to the record-breaking 1997/98 over the last few decades with the advent level gradients across the Indo-Pacific Co-authors event. Here we employ atmosphere and of ARGO and satellite observations, Warm Pool. Increased absorption of S. Sadrafshari Zanjan University, Iran), ocean reanalyses from ECMWF (ORAS4, and the more recent efforts to monitor solar radiation consistent with positive L. Scarascia (CMCC, Italy) ORAS5, ERA-Interim) and JMA (JRA-55) the Atlantic Meridional Overturning SST anomalies prevailing in the eastern in conjunction with satellite data (CERES- Circulation (AMOC) using arrays such as Iran appears to be a critical host spot subtropical Pacific was a secondary EBAF) to compare anomalous energy RAPID and OSNAP. These have shown of climate change. In fact, it is located effect damping the tropical pacific flows through the climate system during decadal timescale changes across the in the central part of a stripe going from OHC discharge. these two El Niños. North Atlantic including in heat content, the Arabian Peninsula to the Eurasian As a result, the 2015/16 El Niño left heat transport and the circulation. steppe characterized by steep increase This perspective is only possible thanks the Pacific in a state recharged for the of temperature in the second half of to the revolution on the ocean observing However there are still significant occurrence of another El Niño event, the 20th century. Here we investigate systems and analysis capabilities in real gaps in the observational coverage, only two years after the previous one. to which extent the ERA-Interim (the time. We show that despite its extreme and significant uncertainties around This conclusion is supported by seasonal continuously updated ECMWF 1979-to- surface characteristics, there was no some observational products. Ocean prediction systems that – at the time present reanalysis), ERA20C and 20CR longer lasting cooling of tropical Pacific reanalyses integrate the observations of writing – indicate the possibility (ECMWF and NOAA ESRL 20th century subsurface waters associated with the with a dynamically consistent ocean of another El Niño event for the re-analyses) reproduce the temperature 2015/16 El Niño. model and are potentially tools that can winter 2017/18. behavior during the period 1979-2010 be used to understand the observed In fact, tropical Pacific upper ocean heat that is recorded at 15 meteorological changes, however the suitability of the content (OHC) at the end of 2016 was stations in the western half of Iran. reanalyses for the task must also be higher than at the beginning of 2015 assessed. We use an ensemble of global Results are not free of problems. For all by about 7.1±0.5 ZJ, which is in stark ocean reanalyses in comparison with stations ERA-Interim and Era 20C are contrast to statistical expectation and observations in order to examine recent systematically biased low with respect previous big El Niño events like that in changes in the North Atlantic. to observations, while 20CR biases are 1997/98 (-15.7±4.3 ZJ OHC loss). The locally large, but with different signs in main reason for this surprising result different parts of the area, so that the
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 107 Section 4 overall bias is actually smaller than the Observed wave spectra characteristic two other datasets. Correlation between Validation of the SWAN model parameters were compared with the ones Visual analysis re-analyzes and observed time series has simulated through the regional numerical with wave spectra observation in Author Philip Brohan in general a seasonal connotation, with propagation wave model SWAN with a 20 the Arvoredo marine biological Affiliation Met Office Hadley Centre low values in summer and high values in reserve, Santa Catarina, Brazil meter resolution allowing to investigate winter. the model reliability such as the One of the strengths of reanalyses is in Author Pietro Albano robustness of the boundary conditions. For almost all stations ERA-Interim their detail – they describe the complex The results show a good agreement presents the largest correlation among Affiliation BMingegneria structure of the atmosphere, showing the between observed and simulated wave the three datasets. However, considering Co-authors behaviour of many variables on a range data with mean square error and bias for trends, there is a large discrepancy Davide Franco (Lahimar-UFSC), of space and time scales. This strength the significant wave height of 0.3 and 0.2, between the small values of 20CR (with Alejandro Donnangelo (Lahimar-UFSC) makes them difficult to appreciate and respectively. As for the peak period, a annual values close to 2K/century) and inter-compare – it is hard to capture their This study provides a comparison mean square error and a bias of 1.9 and the very large trends of ERA20C and value and accuracy in simple numerical between wave observations in shallow 0.8 seconds were instead calculated. ERA-Interim (around 6.5 and 8.5K/ metrics. water and wave data simulated through Low frequency wave energy coming Century, respectively). CRU trends are the SWAN model, forced in deep water from E-ESE and SES-S bins presents Modern scientific visualisation methods large as well (slightly below 6K/Century) by Hindcast reanalysis directional wave the highest mean square error in the offer a powerful tool for analysis and and much closer to trends in ERA20C spectra of the WW3_NOOA model. From spectra. This is due to the Arvoredo comparison. Careful choice of colour and and ERA-Interim than to 20CR. March 2014 until April 2016, within the Island which creates a diffraction pattern structure allows plots capturing spatial Differences among trends are mostly MAArE project, it has been possible that causes a wrong estimate of the peak detail for several variables simultaniously, related to the two last decades of the to characterize the wave regime in the direction, highlighting the importance of a and video shows their time-evolution. 20th century, when the behavior of marine biological reserve of Arvoredo, multimodal wave spectra identification. ERA-Interim and ERA20C has been situated 11 Km north of the island of characterized by a very large negative Florianopolis, in the south Brazilian bias with respect to observations, which shore. has been decreases rapidly (without The two years survey was carried out anyway vanishing) afterwards. On the by an Acoustic Doppler Profiler (ADP) contrary, ERA20C time series show located at a depth of 21 meters and a flatter behavior than other datasets it allowed to analyse the directional during the whole period. wave spectra characteristic parameters through the extended maximum entropy method (Haschimoto et al., 1994). Local wave regime mainly showed east seas with a period between 6 and 8 seconds and significant wave height between 0.5 and 1 meter.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 108 Section 4
progression that fills the needs of the WCRP Task team for the community and contributes to the Intercomparison of ReAnalyses WCRP mission. The primary charge (TIRA): Motivation and Progress to the TIRA is to develop a reanalysis intercomparison project plan that will Author Michael G. Bosilovich attain the following objectives. Affiliation NASA GSFC GMAO 1) To foster understanding and Co-authors estimation of uncertainties in TIRA Member reanalysis data by intercomparison Reanalyses have proven to be an and other means. important resource for weather and 2) To communicate new developments climate related research, as well as and best practices among the societal applications at large. Several reanalyses producing centers. centers have emerged to produce new atmospheric reanalyses in various 3) To enhance the understanding of forms every few years. In addition, land data and assimilation issues and and ocean communities are producing their impact on uncertainties, leading disciplinary uncoupled reanalyses. to improved reanalyses for climate Current research and development in assessment. reanalysis is directed at (1) extending the 4) To communicate the strengths length of reanalyzed period and (2) use of and weaknesses of reanalyses, coupled Earth system models for climate their fitness for purpose, and best reanalysis. practices in the use of reanalysis While WCRP’s involvement in the datasets by the scientific community reanalyses communities through its This presentation outlines the need Data Advisory Council (WDAC) has been for a task team on reanalyses, their substantial, for example in organizing intercomparison, the objectives of the international conferences on reanalyses, team and progress thus far. a central team of reanalyses expertise is not in place in the WCRP structure. The differences among reanalyses and their inherent uncertainties are some of the most important questions for both users and developers of reanalyses. Therefore, a collaborative effort to systematically assess and intercompare reanalyses would be a logical
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 109 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 J. Muñoz-Sabater (2), S. Boussetta observationally based ELR over the (2), T. Komori (3), S Hirahara (3), and mechanism sounding data and the conventional U.S. using the GHCN temperature data, data, a worse forecast is produced by G. Balsamo (1). 1: Instituto Dom Luiz, showing a good agreement. The method Author Duming Gao assimilating operational sounding data Faculdade de Ciências, Universidade is used to downscale ERA5 to about 9 Affiliation Institute of Plateau individually; by introducing intensive de Lisboa, 2: European Centre for km globally and validated against in-situ Meteorology, China sounding data, the strength of initial Medium-Range Weather Forecasts, temperature observations and compared Meteorological plateau vortex(PV) and SWCV are 3: Global Environment and Marine with simulations without any topographic Administration (CMA) enhanced due to the increase cyclonic Department, Japan Meteorological correction and with a constant ELR. perturbation on the initial wind field, Agency Co-authors The results suggest some benefits besides, the more unstable stratification Yueqing Li (Institute of Plateau Temperature near the surface varies with of using this new ELR over complex adjusted by data assimilation makes Meteorology, China Meteorological altitude accordingly to the environmental terrain regions, when compared with a the model more easy to produce large Administration (CMA)) lapse-rate (ELR). The ELR depends constant value, and suggest that this precipitation in initial times as the on the overlying air masses, large- new methodology could be used as a Based on the Weather Research observation’s magnitude. scale situation and local effects. The default for downscaling temperature Forecast(WRF) model and WRF data The experiment reveals the generation characterisation of the ELR has several from reanalysis on the global/regional assimilation system(WRFDA), an and maintenance of SWCV on 700hPa applications, in particular to downscale scale where local in-situ observations are sensitivity analysis is conducted in a in this case is not rely on high potential global/regional numerical weather scarce and computational resources limit data assimilation experiment using vorticity on upper air, it must need predictions, and reanalysis in complex dynamical downscaling. operational sounding data and the positive vorticity transported by the terrain regions. intensive observed data of Southwest enhanced vertical movement which China vortex(SWCV) scientific experiment From an observational point of view, caused by latent heat release of on a heavy rainfall caused by vortex in complex terrain regions also constitute precipitation condensation. Sichuan Basin. a challenging environment due to the difficulties associated with the installation and maintenance of observational 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 110 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 meteorological stations data of near annual cycle of temperature but they differ in the data that are of temperature change on sub-basins and data from the NCEP across the Northern Hemisphere assimilated: both ERA-20C and 20CR the temporal and altitudinal Reanalysis database, the trends of the assimilate surface pressure data; ERA- dynamics of agricultural areas 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 in 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 Phil Jones (Climatic Research Unit, Blancas Through the thermal bands of the a form of control, in the sense that the University of East Anglia), Cheng Qian Affiliation Centro de Investigaciones Landsat images and the application data are not constrained by observed (CAS Key Laboratory of Regional de Zonas Aridas of the standard deviation of the MSLP or marine wind data, as is the case Climate-Environment for Temperate East temperature, it was determined that with the other reanalyses. Most previous Co-authors Asia, Institute of Atmospheric Physics, the area with the greater variation of analyses of the annual cycle have only Grégry Damman (CIZA UNALM), Chinese Academy of Sciences; and temperature, between 2 and 4 °C, was examined changes over the latter half of Maria Fernanda de los Rios University of Chinese Academy located in the altitudinal range of 3600 the twentieth century, but the century- (CIZA UNALM) of Science) to 4000 meters. The data obtained show long view afforded by these reanalyses The study of the effect of the temperature an increase in temperature variability, The annual cycle of temperature has allowed us to examine trends in the change on the dynamics of ecosystems which could be influencing an increase accounts for more than 90% of the annual cycle back to 1902. is getting attention in a context of in the use of agricultural lands at higher variance of surface air temperature climate change. This effect may be more across extra-tropical regions. It is demonstrated from the comparison altitudes in the Vilcabamba sub-basin. of these datasets that much of the sensitive for mountain ecosystems, This situation would cause a change Observations have indicated profound especially because of the altitudinal changes in the annual cycle throughout interannual to lower-frequency variability in the vegetation found naturally in the in the amplitude of the annual cycle is gradient. In the Peruvian Andes, highlands, affecting ecosystem services the twentieth century, but the factors having tropical mountains, the effect of influencing these trends remain poorly attributable to synoptic variability, with that the area offers. oceanic coupling being the critical factor. temperature variation may be more easily understood. In this analysis we evaluate observable. The present work aims to these changes in the annual cycle Furthermore, the variability in the phase and amplitude of the annual cycle during describe the dynamics of agricultural through the comparison of four reanalysis areas in the southern Peruvian Andes, in datasets (ERA-20C, ERA-20CM and two the post-1950 period was unusual in the context of the twentieth century, although the Vilcabamba river basin, from 1986 to versions of NOAA-20CR) against the 2009. It also looks forward to explain the CRU-TS dataset. uncertainty is greatest before ca. 1930 as a result of relatively sparse data possible effects of temperature change The Modulated Annual Cycle (MAC) is coverage during across most regions of on agricultural areas in the gradient calculated from the data using Ensemble the northern hemisphere. between 2400 and 4000 meters. Empirical Mode Decomposition (EEMD), With the use of Landsat and ASTER from which phase and amplitude metrics images, the land use changes in relation are derived. to height was modeled. It showed an increase on agricultural area use between the 3600 and 4000 m.a.s.l.,
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Analysis of mean state of SST and sea Major issues in the reanalyses are narrow channel approximately 450 km Assessment of different ocean surface salinity (SSS) reveals that ORAS4 underestimation of upper ocean stability in width and 2600 km in length. The reanalyses over the Tropical is better comparable with observations/ and surface current in EIO and over precipitation resulting from the inland Indian Ocean EN4 data, which is followed by SODA, estimation of vertical shear of current penetration of this AR is also analyzed. ECDA and GODAS. The surface and variability of different physical To consider this event in a climatological Author Ananya Karmakar circulation in ORAS4 is closer to OSCAR oceanic variables. To improve the skill of context, IWV and IVT data are derived Affiliation Indian Institute of Tropical compared to the other reanalyses. reanalyses over the TIO, salinity vertical from ECMWF for the month of February meteorology However mixed layer depth (MLD) is structure and upper ocean circulation over the 20-year period from 1996- better simulated by SODA, followed by need to be better represented. Co-authors 2015. Dates of observed landfalling ECDA, ORAS4 and GODAS. Pune- 411008, India, Department ARs for water years (WYs) 1998-2008 of Atmospheric and Space Sciences, Seasonal evolution of error indicates that Atmospheric River Event over that impacted the California coast Savitribai Phule Pune University, the highest deviation exists during spring the Eastern Pacific in February (32.5N-41.0N) are obtained from SSM/I. Pune -411007), Anant Parekh (Indian and summer in SST and MLD over the 2014: Analysis and Dates for February 1996-1997 and Institute of Tropical Meteorology (IITM), TIO in GODAS. These errors may play 2009-2015 are based on ECMWF with Pune- 411008, India), J. S. Chowdary very decisive role since GODAS (during Climatological Context the constraint that IWV >20 mm for (Indian Institute of Tropical Meteorology spring) is widely used to initialize the Author Deveshi Buch observations that are 12 hrs. apart. (IITM), Pune- 411008, India), and C. coupled models for seasonal prediction Affiliation Vista del Lago High It is observed that the February 2014 AR Gnanaseelan (Indian Institute of Tropical of Indian summer monsoon. Statistical School event is one of five significant events in Meteorology (IITM), Pune- 411008, India) analysis with concurrent data of EN4 for the 20-year period, as measured by IWV the period of 1980-2010 supports that This study makes an inter comparison Atmospheric rivers (ARs) are narrow and >30 mm. An algorithm was developed the difference and standard deviation of ocean state of Tropical Indian Ocean intense plumes of water vapor that are to filter the raw data in order to meet a (variability strength) ratio for SSS and (TIO) in different ocean reanalyses such known causes of heavy precipitation threshold of >20 mm (IWV) and >250 MLD is mostly greater than one. as Global Ocean Data Assimilation events. This is an analysis of the kgm-1s-1 (IVT) for a duration of >12 hrs. System (GODAS), Ensemble Coupled In general the strength of variability is evolution, transport, and landfall of a to expose values that represent AR Data Assimilation (ECDA), Ocean over estimated by all the reanalyses. significant AR event in February 2014 events. A composite mean of the IVT Reanalysis System 4 (ORAS4) and Further analysis with in-situ buoy over the Eastern Pacific and West Coast values is also calculated, showing peak Simple Ocean Data Assimilation (SODA) observations supports that MLD errors 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 over the equatorial Indian Ocean climatological context. the composite AR. observations, satellite observed Sea (EIO) and Bay of Bengal are higher Integrated Water Vapor (IWV) and Surface Temperature (SST), EN4 data, than estimated with respect to EN4 Integrated Vapor Transport (IVT) values and ocean surface current analysis real data. Overall ORAS4 displays higher are calculated based on NASA MERRA time (OSCAR). correlation and lower error among all and ECMWF ERA-Interim reanalysis reanalyses with respect to both EN4 data datasets. The AR is characterized by and buoy observations. high levels of IWV (~29 mm) as well as IVT (~759 kgm-1s-1). Analysis of the synoptic-scale progression of upper-level extratropical cyclones and anticyclones shows the flow of vapor transport in a
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changes in recent years in China, and it However, few reanalyses capture the more sever over the area which leads to Changes of atmospheric improves correlation of the precipitable observed long-term PW changes, flood, landslide and loss of many lives. water (PW) with precipitation and the primarily because they show spurious wet precipitable water in observations In the present study rainfall has been spatial coherence of the PW trend during biases before about 2002. This deficiency and reanalysis over China taken as the criteria for predicting the recent 40 years. The PW variations results mainly from the discontinuities intensity and location of Mandi cloudburst Author Tianbao Zhao and changes are highly correlated with contained in reanalysis RH fields in the using ANN approach, Input data to which Affiliation Institute of Atmospheric those in lower–midtropospheric mean mid-lower troposphere due to the wet was obtained by performing numerical Physics (IAP), Chinese temperature (r = 0.83), with a dPW/dT bias in older radiosonde records that are simulation using the Weather Research Academy of Sciences slope of ~7.6% K−1, which is slightly assimilated into the reanalyses. Thus, and Forecasting (WRF) model. WRF (CAS) higher than the 7% K−1 implied by more efforts are needed to remove model was configured with spatial Clausius–Clapeyron equation with a spurious changes in input data for Co-author resolution of 7km over three sites of constant relative humidity (RH). future long-term reanlayses. Aiguo Dai (Department of Atmospheric cloudburst that is Uttarkashi (30.7268 and Environmental Sciences, University The radiosonde data show only N, 78.4354 E), Leh (34.1526 N, 77.5771 E) at Albany, SUNY, Albany, New York, USA) small variations and weak trends in Combination of WRF and ANN and Mandi (31.706 N, 76.93 E). tropospheric RH over China. Using these Radiosonde humidity data provide the Model for predicting cloudburst Different physics option and convection homogenized observations, the PW from longest record for assessing changes in parameter with single domain for the NCEP/NCAR, NCEP/DOE, MERRA, Author Abhishek Sharma atmospheric water vapor, but they often Uttarkashi, Leh and multiple nested 2 JRA-55, JRA-25, ERA-Interim, ERA-40, Indian Institute of contain large discontinuities because Affiliation way domain for Mandi has been used to CFSR and 20CR reanalyses is evaluated Technology Roorkee of changes in instrumentation and best simulate the event. Three different for the period from 1979-2012 (1970-2001 observational practices. Co-author Neural network training was done using for ERA-40). Dr. Kamal Jain (Department of Civil In this study, the variations and trends MATLAB with input data of Uttarkashi Engineering, Indian Institute of in tropospheric humidity (up to 300 Results suggest that the PW biases in having 11 inputs and 89 samples, Leh Technology Roorkee, Roorkee) hPa) over China are analyzed using a the reanalyses are within ~20% for most having 11 input and 991 samples, Mandi newly homogenized radiosonde dataset. of northern and eastern China, but the Himalayan states of India such as having 11 inputs and 85 samples using There are, however, many spurious reanalyses underestimate the observed Himachal Pradesh and Uttarakhand Feed Forward Neural Network with Back changes and discontinuities in the PW by 20%–40% over western China, are prone to cloudbursts, landslides Propagation algorithm. and by ~60% over the southwestern raw radiosonde records resulting from and other catastrophic events due to Hyperbolic tangent sigmoid function Tibetan Plateau. The newer-generation changes in instruments, observational its geographical structure. Severity of at hidden layer and linear function at reanalyses (e.g., JRA25, JRA55, CFSR practice, processing procedures, station these events has a strong correlation output layer was taken as the activated and ERA-Interim) have smaller root- relocations, and other issues. Recently, with the orographic precipitation. On 8th function for training the three networks. mean-square error (RMSE) than the the daily humidity records radiosonde August 2015 between 00 to 06 hr UTC, Number of hidden layers was decided older-generation ones (NCEP/NCAR derived from about 130 Chinese stations heavy and continuous rainfall lead to a using Kolmogorov’s theorem. Prediction NCEP/DOE and ERA-40). Most of the were homogenized using a new approach cloudburst event over Mandi district of was done at Mandi using three trained reanalyses reproduce well the observed developed by Dai et al. (2011). Himachal Pradesh. neural networks. Results are shown as the PW climatology and interannual observed and predicted rainfall at 6hr time It is shown that the homogenization variations over China. The interaction of extensive monsoon removes the large shifts in the original flow and the elevated terrain makes the step. records of humidity resulting from sonde high rainfall event persistent as well as
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 113 Section 5
all calendar months with the possible In summer, the OGWD obtained from Comparing traditional exception of August, for the period of the Comparison of two the traditional scheme is generally climatological records with regional reanalysis (1995-2014). parameterization schemes of confined in the lower stratosphere north of 30°N. In the new scheme the mid- reanalysis time series over The correlation coefficients between orographic gravity wave drag latitude (about 30~60°N) OGWD is also Germany COSMO-REA6 and traditional monthly using the ERA-Interim reanalysis mainly located in the lower stratosphere, means from gridded station data Author Andrea Kaiser-Weiss Author Xin Xu while at high latitudes notable OGWD are higher than 0.97 for most areas. is found within a deep column of the Affiliation Deutscher Wetterdienst Differences between the regional Affiliation Nanjing University stratosphere. In winter, both the new and Co-authors reanalysis and the gridded station data Co-author old parameterization schemes produce M. Borsche (DWD), D. Niermann (DWD), appear at Northern Germany, likely Yuan Wang (School of Atmospheric OGWD in the whole stratosphere, F. Kaspar (DWD) because of the lack of data coverage in Sciences, Nanjing University) especially in the upper stratosphere of the traditional method. More differences Traditionally, gridded station data are Developed in early 1980s, the high latitudes. become apparent when reducing area the basis to estimate climatological time parameterization of orographic gravity size. To sum up, the new parameterization series of, e.g., the development of mean wave drag (OGWD) is now implemented scheme tends to give smaller OGWD temperature over Germany. Discrepancies could be caused by in nearly all the state-of-the-art general in the lower stratosphere but larger various reasons, for instance by local circulation models (GCMs) and chemistry Here we compare this time series OGWD in the mid-upper stratosphere. influences on the station observations, climate models (CCMs). However, current against the one derived from the regional The difference between them mainly or by a lack of the reanalyses to capture OGWD parameterization schemes only reanalysis COSMO-REA6 as well as occurs over the Tibet Plateau, the Rocky the processes observed at the stations. consider the vertical propagation of against the global reanalysis ERA-Interim. Mountain, and the Greenland. Here we show our results in attempting orographic gravity waves (OGWs), while We focus on temperature observations to distinguish between these options and in reality these waves propagate both performed 2m above ground. There are the implications for trend analysis over vertically and horizontally. discrepancies in the statistical properties Germany. on scales from the hourly scale to the The lateral spread of OGWs can reduce decadal scale. For the whole of Germany, the local wave amplitude with height, the COSMO-REA6 annual cycle matches thereby giving rise to wave breaking and the traditionally derived one, allowing for hence OGWD at higher altitudes. Using a bias with annual cycle which is well- the Gaussian beam approximation (GBA) known for COSMO model. approach, a new OGWD parameterization scheme is proposed which explicitly The year-to-year variability is higher deals with the horizontal propagation of than the bias. Both reanalysis data OGWs. This new scheme is compared and traditional data track the annual with the traditional scheme by examining anomalies. For trend applications it is the OGWD in the stratosphere of of interest whether the bias is constant Northern Hemisphere during 2011-2016, over the decades. This can be confirmed using the ERA-interim reanalysis data for the annual mean over Germany and produced at the European Center for Medium-Range Weather Forecasts (ECMWF).
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The reliability of the forecast ensemble allocation of resources, while minimizing oil spill simulation results. The aim is ECMWF probabilistic forecasts will be determined by validation using the risks and costs (Keeney, 1982; Mata to find the best wind inputs for optimal for near-real-time monitoring historical sets of hindcasts. The and Corchado, 2009). prediction of oil spills in the Persian Gulf. inherent uncertainty of seasonal WF We will use the observed Mina Al-Ahmadi of drought in the trans-boundary Many studies develop methods, tools, was quantified by issuing probability oil spill event for the Mike 21/3 model Prut River Basin and decision support systems to identify statements about future observable verification. The calibrated model will be potential oil spill sites, support oil spill Author Vera Potopova outcomes based on current and past at the core of a decision support system risk management, and reduce the forecasts (hindcasts) and observations. for oil spill management and coastal area Affiliation Czech University of adverse effect of oil spills (Mokhtari et al., The WF will be withdrawn from ECMWF protection in the Persian Gulf. Life Sciences Prague, 2015; Ko and Chang, 2010; Lehikoinen et throughout the project in order to update Department Agroecology al., 2012; Jolma et al., 2014; Juntunen et the information provided by the models and Biometeorol al., 2005). Soltanpour et al. (2013) studied namely in terms of irrigation management Estimation of hourly and daily the key factors influencing the movement The aim of this study is to validate a during the growing seasons. clearness indices and diffuse of oil spill in the Persian Gulf, and found probabilistic methodology from the fraction, over Port Harcourt and that wind was the most important factors. ECMWF (Centre for Medium-Range In marine environment the wind forcing Kano Nigeria using NCEP/NCAR Weather Forecasts) for near-real-time Effect of wind forcing on oil spill data is obtained from surface (synoptic) satellite data drought monitoring and forecasting simulation in the Persian Gulf station, satellite observation, or numerical to optimization of crop irrigation Author Vincent Omole Author Sahar Mokhtari atmospheric model. Model assimilation management in the Prut River catchment. Affiliation College of Education Affiliation Ports and Maritime techniques are used to improve the wind The trans-boundary Prut River Basin Ikere Ekiti Nigeria model forecast. According to Jones is one of the most drought vulnerable Organisation (I.R.Iran) (1999), meteorological forecasts of wind Co-authors areas in the Republic of Moldova, Co-author from numerical model can be used as B. Adeyemi, (Federal University of Romania and Ukraine due to high water Ji´rí Kadlec input to oil spill simulation with same Technology Akure, Nigeria), O. Oloniyo, exploitation. This paper presents the Oil pollution is a serious environmental accuracy as field wind observations. (Federal University of Technology Akure) research undertaken within the project problem with critical impacts on marine Temporal variations in wind were more In this study, estimation of clearness IMDROFLOOD (http://imdroflood. and coastal habitats, wildlife, fisheries important than spatial variations, and index (KT = H/H0) and diffuse fraction meteoromania.ro). and human activities (Allan et al., 2012; a high temporal resolution of the wind (KD = HD/H) were calculated using Fattal et al., 2010; Carson et al., 1992). Seasonal daily weather forecast (WF) of should be used In the use of oil spill available satellite data obtained from For preventing future oil spill disasters maximum and minimum temperatures model for contingency planning and National Centre for Environmental and to develop optimal planning and and precipitation from the ECMWF management, a stochastic simulation Prediction (NCEP) and National Centre management strategies in response to were collected and downscaled for the with multiple events is often used (Eliot et for Atmospheric Research (NCAR) data oil spill events, an environmental risk different locations from upstream to al. 2014). base covering a period of 10 Years downstream of the Prut River Basin. assessment with capacity to support The main goal is to test the effect of (2005–2014) for Port Harcourt and Kano These forecasts were used to produce decision making is needed (Fabbri, 1998; different types of wind forcing (constant stations which are Coaster and Sahel the ensemble operational seasonal Assilzadeh and Gao, 2010). This requires wind, spatially variable wind, time regions respectively. Direct solar data predictions and constitute models inputs. identifying and prioritizing areas in the variable wind) and wind input data on and diffuse solar data collected were Short (1-month) and medium (3 and coastal zone where there is a need for an the simulated oil spill trajectory, and added to give the Global solar radiation. 7-month) range WF were retrieved. test which data inputs provide the best
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 115 Section 5
The clearness index (KT) which is Weather Center. The acceptability of This research examines the role that the ratio of the global solar radiation Evaluation of Waterspouts by the Szilagyi Waterspout Index for four large-scale circulation plays in local obtained at the surface to the total solar Szilagyi Waterspout Nomogram extreme cases are computed and the storminess for the North Atlantic islands radiation at the top of the atmosphere and Triangle Diagram availability of waterspout predictions of Orkney and Shetland. Automatic Lamb was obtained. The diffuse fraction have been examined in the study. In classification is applied to twentieth (KD) was obtained from the ratio of the Author Sevinc A. Sirdas addition, a triangle diagram was created century reanalysis data to typify large diffuse solar radiation incident on the Affiliation Istanbul Technical for the waterspout cases in the Antalya scale circulation patterns and calculate horizontal level of earth surface (HD) to University region for period of 2000 and 2012, which measures of storminess, which are the global solar radiation that incident Co-authors is composed of Sweat Index, relative then validated using observations from on the surface level (H). The computed Özmen, I., Yavuz, V.Y., Kaya, S. and humidity and 850mb wind speed. Key meteorological stations on the islands, clearness index value were used to Aydın, M words: Climate Change, Extreme, Vortex, obtained through the UK Met Office. characterize the sky conditions into clear Waterspout, Szilagyi Waterspout Index, This research uses the ERA-20C (1900- skies and overcast skies. Port Harcourt Climate change impacts on extreme Triangle Diagram, Demre. 2010) reanalysis dataset produced by with low clearness index indicated low and rare weather events are much more the European Centre for Medium-Range global solar radiation while Kano with obvious so that many scientific studies Weather Forecast. Daily mean sea level large clearness index indicated high have been focused on worldwide. The Exploring storminess on North pressure (MSLP) data was obtained global solar radiation. The implications of connection between the formation of Atlantic islands using reanalysis at 0.125° x 0.125° resolution, to which these results on the effective utilization of waterspouts that are considered as data the weather classification method solar energy are discussed. The results rare event for Turkey and the climate Author Aideen Foley was applied. By characterising the also serve as very useful for solar energy change has been a matter of curiosity. relationship between large-scale climate collectors in designing and estimation The vortex incident and waterspout have Affiliation Birkbeck, University trends and regional weather patterns, this of solar application systems. Keywords: been observed 260 times in the period of London research adds to our understanding of Clearness Index, Diffuse Fraction, Global between 1997 and 2015 at Turkey, and Storm events impact on the built and contemporary changes in storminess on Solar Radiation the most of them were observed in the coast and lakes of Antalya. In this natural environment of North Atlantic North Atlantic islands, and can thus aid study, the data sets of ground base islands, with a range of environmental, in anticipating and adapting to further, stations and ERA- Interim are analysed economic and social effects. future change. for four extreme waterspout cases in On the island of Orkney, for example, Kale – Demre, Antalya station which there are implications for the field of were observed at the period between heritage conservation, with World 2008–2013 were discussed in the study. Heritage sites such as the Neolithic ECMWF Reanalyse data ERA-Interim is settlement of Skara Brae at particular risk used for different vertical heights, and from increased erosion. Recent episodes the meteorological variables of ERA- of storminess in the UK invite speculation Interim are downscaled on the station as to whether a shift is underway towards of Kale – Demre. more extreme weather. However, the The vertical thermodynamic structure complex spatial dimensions of the of vortexes are analysed by diagrams regional storm climate necessitate more and vertical indexes of Plymouth State localised study.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 116 Section 5
able to reproduce the principal fire risk results were validated using root mean probability distributions and expected Fire Susceptibilty under different areas which are concentrated in the square (RMSE), accuracy and correlation values, at single points (time extremes) atmospheric conditions Sahelian region and in northern of South coefficient, R. and over areas (space-time-extremes). America from December to March, in The feedforward neural networks In particular, the Tayfun nonlinear Author Alex Santos da Silva subtropical Africa and Midwest region of model of five inputs (latitude, longitude, model is considered for the probability Affiliation Federal University Brazil from July to October. of Vicosa elevation, month and year) had the best and expected value of maximum crest In almost all continents the efficiency results with values of 0.86 and 6.68 for heights, while for the maximum crest- Co-authors of the model was approximately 70% in R and RMSE respectively. And given to-through wave heights expected F. Justino (Federal University of Vicosa), presenting occurrences over 10 fires in the accuracy of 93.32%, the networks values are estimated combining the N. Leonardo (Federal University of the grid cell. The PFRI reproduces areas can effectively be used to forecast for Tayfun nonlinear model and the Quasi- Vicosa), V. Schumacher (Federal with high fire activity and those ones other locations in Nigeria. Tools such Determinism theory. University of Vicosa), A. Comin which present atmospheric patterns as neural networks that have the ability For our purposes, we use the directional (Federal University of Vicosa) totally distinct from the equatorial zone, to understand the patterns in any given wave spectra produced by ERA-Interim indicating that this index is an useful tool set of data are highly recommend for Based on Era-Interim Reanalysis and over the entire global oceans, including for forecasting fire occurrence worldwide forecasting and studies of trends. GPCP (Global Precipitation Climatology marginal and enclosed seas (e.g., because it is based on regionally Project) datasets we analyzed the Mediterranean Sea), with 1°x1° spatial vegetation and climate factors. vulnerability to wildfire occurrence from Global climate of extreme ocean and 6-hour temporal resolutions. The 2001 to 2015. The investigation applies waves from ERA-Interim spectral parameters provide parameters a Potential Fire Risk Index (PFRI) which Forecasting Rainfall in Nigeria of the probability distributions and runs a roughly exponential function Author Francesco Barbariol expected values of extreme waves. adjusted for three atmospheric layers Using Neural Networks Affiliation ISMAR-CNR of the Haines Index (HI). The PFRI is set Author Nsikan Obot An analysis of the directional spectrum with eighteen classes of vegetation as Co-authors parameters and extreme waves over Affiliation University of Lagos boundary condition extracted from the A. Benetazzo (ISMAR-CNR, Italy), the ERA-Interim reanalysed period International Geosphere and Biosphere Co-authors L. Cavaleri (ISMAR-CNR, Italy), M. Sclavo (1979-2016) is conducted in order to: Program. I. Humphrey (Department of Physics, (ISMAR-CNR, Italy), JR. Bidlot (ECMWF, (i) highlight regions of the oceans that University of Lagos) UK), P. Janssen (ECMWF, UK) are more prone to the development of This is formulated on the principle that extreme waves, (ii) assess the presence the vegetation fire risk increases with Rainfall is about the most complex We present an application of the ERA- parameter in meteorological studies Interim dataset that we use for the global of climatological trends in extreme the increasing duration of dry periods, waves, taken into account the 1991 type and natural cycle of vegetation and if it is adequately forecasted, the analysis of extreme ocean waves. The problematic fallouts of excessive rain can main goal is to assess, for the first time, discontinuity in significant wave height phenology, maximum temperature and statistics due to the beginning relative humidity of the air. be mitigated. From a total of fifty years the global signature of the multi-decadal data for twenty seven locations across climate of extreme waves. Features of of altimeter assimilation. The daily global active fire from the Nigeria, forty years data were deployed in extreme waves are here predicted in a Satellite Terra/MODIS was used various artificial neural networks models probabilistic sense, i.e., the maximum to validate the analyses. It was to forecast for ten years of rainfall. The crest and crest-to-through wave heights demonstrated that under current climate in a sea state are treated as random and vegetation conditions the PFRI is variables, of which we estimate the
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 117 Section 5
Big Data of Earth Observation is split into maps are able to explain the atmospheric GREENTOP – Gamification of parts individually processed, constantly High Resolution Composite conditions at one to five days prior to the cRowdcomputing to ENhance updating the Earth view from space. Maps for Extreme Rainfall in occurrence of the events in Indonesia, EarTh Observation data Processed data will be publicly available Indonesia which has never been explored so far. Processing for viewing, while thematic downloads will be charged. Potential customers are Author Heri Kuswanto Author Sorin POP Environment NGO’s, local authorities, Affiliation Institut Teknologi Sepuluh High resolution regional Affiliation Indeco Soft small and medium sized business in the Nopember (ITS) reanalysis: a tool for the forestry and agriculture domains, while identification of extreme wind Co-authors Co-author cooperation with universities in imagery Gabriel ZETE (Indeco Soft), Ana Maria Kiky Ferawati (Institut Teknologi Sepuluh surges in the German Bight research projects is also envisaged. The POP (Indeco Soft), Ciprian GHISE Nopember-Indonesia) , collaboration with startup communities Author Natacha Fery (Indeco Soft) through preferential data access and Climate change has increased the Affiliation Deutscher Wetterdienst The European Space Agency provides accessible fees has the purpose of intensity of extreme weather events Co-authors free access to great amounts of data boosting further innovation and creativity. in Indonesia. One of the strategies B. Tinz (DWD), A. Ganske (BSH), from its space missions. Processing it to minimize the risk is by developing Data will be processed using well- A. Andersson (DWD), L. Gates (DWD) for applications in forestry, land cover, a forecasting tool enable to provide known algorithms for high resolution land use, precision agriculture and other an accurate prediction about the In the context of global climate change, multispectral imagery (Sentinel2) and fields requires huge capabilities. Through occurrence of extreme events. This interest in the study of very severe storm multiple instruments data (Sentinel gamification, a community of enthusiasts research developed high resolution surges and their impacts on the southern 3). GREENTOP – Gamification of is encouraged to share their computing composite maps designed specifically North Sea and more particularly in the cRowdcomputing to ENhance EarTh power to rapidly process small portions for extreme rainfall events in Indonesia. German Bight has increased over the last Observation data Processing encourages of imagery. Members can also participate High resolution refers to the grid space of decades. In the framework of the research internet users to support ESA’s initiative actively in validating data manually, the reanalysis dataset used to create the project EXTREMENESS, funded by the of distributing free spatial data. providing a human verification of the map. ERA-Interim reanalysis dataset has German Federal Ministry of Education and computer processed information. Further applications include tacking input been chosen as the the input. Research, two methods are implemented from IoT devices for enhancing analysis to identify extreme wind surges likely User involvement, both for automated The composite maps provide information algorithms. This work is the object of a to cause significant damages along the processing and manual validation will about the dynamic pattern of some feasibility study financed by the European coast of the German Bight. be encouraged through a gamification weather variables in atmospheric (upper) Union’s Horizon 2020 research and process (virtual badges, eCards, levels as well as information about To achieve this goal, high resolution innovation programme – SME Instrument, premium access to data, gifts of active zones associated to the events. reanalysis from the regional model under grant agreement No. 773660 and independent processing units – IoT Bootstrap resampling approcch has been COSMO-REA6 (Deutscher Wetterdienst, will be complete in October 2017. devices). The Internet of Things, through applied to validate the map with certain University of Bonn) is evaluated small computing modules that process degree of significant levels. by means of recent and historic meteorological observations. A statistical images using energy from renewable Some weather variables in the sources will organize an innovative mesh wind surge model based on wind speed, atmospheric levels show clear patterns wind direction and sea level pressure is network of independent processing units to be used as a guidance to predict providing green processing power. optimized for extreme events that are extreme rainfall events. The composite detected in the dataset.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 118 Section 5
A second method consists of evaluating In these shallow-groundwater systems, the so-called effective wind and its Improving water level and soil soil moisture of the unsaturated zone, Inter-comparison of ERA- extremes. The effective wind is the result moisture over peatlands in a and consequently the energy and Interim, MERRA, NNRP of the projection of the real wind onto global land modeling system water exchange with the atmosphere, reanalysis and GFS-ANL that wind direction, for which the impact is closely coupled to water table depth, analysis data for Wind Resource of the wind on the water level is most Author Michel Bechtold which is thus a key variable that must effective. The present study highlights Affiliation KU Leuven be adequately modeled. We discuss Assessment across India the advantages of using these methods Co-authors the capability of an operational global Author Chinmay Kulkarni instead of the often used high percentile G.J.M. De Lannoy (Department of Earth land surface model to simulate peatland Affiliation Meteodyn calculation for the identification of and Environmental Sciences, Belgium), hydrology. Specifically, we evaluate the severe surges. The accuracy of the Catchment land surface model (CLSM) Co-author D. Roose (KU Leuven, Department of Eric Tromeur high resolution reanalysis is as also Computer Science, Scientific Computing of the NASA Goddard Earth Observing assessed for the storm conditions under Research Group, Belgium), R.H. Reichle System version 5 (GEOS-5) modeling Reanalysis data is extensively used in consideration and climate projections (NASA Goddard Space Flight Center, and assimilation framework, which is one Wind Resource Assessment (WRA) to are analyzed to provide a range of future Global Modeling and Assimilation Office, of the few global land surface models in produce long-term correction series severe wind surges. Greenbelt, Maryland, USA), R.D. Koster which water table depth is modeled at all. of measured wind data. A long-term (NASA Goddard Space Flight Center, A preliminary analysis of groundwater correction series is necessary in order to Global Modeling and Assimilation Office, levels from the GEOS-5 Modern-Era reduce the uncertainties in the short-term 1 Greenbelt, Maryland, USA) Retrospective Analysis for Research and wind observation data . Good data is key Applications version 2 (MERRA-2) and to good WRA and to predict accurate Peatlands are characterized by high wind energy production of a site. soil moisture contents and hydrological other GEOS-5-based land-only products dynamics that differ greatly from those in show very little differences between The objective of the study is to compare biomes on mineral soils. In combination areas with peatlands and those with the wind speed modelled by MERRA, with peatland-specific vegetation dominantly mineral soils. In contrast, ERAI, NNRP reanalysis and FNL analysis characteristics, this leads to distinct observed water table levels show data sets with observations across 10 energy and water fluxes across the soil- strong differences in temporal statistical stations in India over the recent period vegetation-atmosphere interface over moments between peatlands and areas of 2010-2016. The observation data these environments. Covering 3% of the with mineral soils. Therefore, we present is obtained from National Institute of global land surface, peatlands can be an initial attempt to improve the GEOS-5 Wind Energy (NIWE), India. The stations a regionally dominant biome, and thus CLSM performance over peatlands by selected in the study are geographically importantly influence the land surface updating select parameters based on well dispersed across India containing boundary conditions for weather and improved ancillary data and parameter mixture of complex, urban and on-shore climate simulations. However, modeling optimization, while keeping the current locations. These reanalysis data have of peatland hydrology is a challenging GEOS-5 CLSM structure as used in different spatial and temporal resolution task. MERRA-2. of grids.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 119 Section 5
The gridded reanalysis data therefore (floods) in the middle and lower reaches Data Relay (AMDAR) system and with is interpolated at the station location Interannual and Decadal of the Yangtze River and the Yangtze- the addition of a turbulence measure (the using inverse distance weighted (IDW) Variations of Moisture Flux Huaihe valley but floods (droughts) in Global Aircraft Data Set, GADS). average technique2 for comparison South China and North China. by Asian Summer Monsoon Wind speeds and turbulence were with observation. Indian continent gets and Associated Rainfall Anomaly On decadal scale, persistent floods in the obtained every 4 sec (~ 1 km spacing) at high wind during south-west monsoon, middle and lower reaches of the Yangtze a fixed flight level (FL370, ~ 225 hPa). We a period of four months from June to Patterns in China River but persistent droughts in South examined the winter (DJF) North Atlantic September. The monthly mean wind Author Jilong CHEN China and North China are mainly linked jet stream region to study secular trends speed profiles of reanalysis data Affiliation Institute of Atmospheric with weakening of VIMF by ASM and in wind speed and “light” turbulence. have shown good agreement with Physics, Chinese a dipole VIMF anomaly in the western The observations were compared with observations and with each other. Academy of Sciences North Pacific after the end of 1970s. In reanalyses over a 12 year period, winter It is found that, all reanalysis monthly view of the in-phase relationship between 2002-2013 (labeled by the January year), The NCEP/NCAR reanalysis data mean values under-estimate the summer rainfall anomalies and VIMF and a CMIP study of doubled CO2. observation values for most of the cases (NCEP-R1) and the ECMWF reanalysis convergence anomalies in China, the We have a sufficiently large dataset (3 though they catch the trend successfully. data (ERA-40) for the period of 1958- analysed results also show interannual billion total global observations, 500,000 The reanalysis data also captured the 2002 are used to estimate interannual and decadal variations of VIMF by ASM for the North Atlantic per winter month) prevailing south-west wind direction and decadal variations of vertically can be better described by the ERA-40 that we are able to subdivide the results of observation successfully. However, integrated moisture flux (VIMF) by reanalysis than the NCEP-R1 reanalysis. into five longitude bands at ten degree the reanalysis data sets failed to frame Asian summer monsoon (ASM) and intervals running from 60°W to 10°W and the correct diurnal variation as per investigate their association with summer find quite coherent behavior along the observation for some stations. rainfall anomalies based on monthly Interannual variations and precipitation at 160 stations in China. secular trends in winter North North Atlantic jet. As would be expected, Overall, the statistical analysis of RMSE, Atlantic jet stream wind speeds our results match the interannual MAE and BIAS of MERRA, ERAI, NNRP The results show that both VIMF by ASM reanalysis variations of the North Atlantic and FNL shows small variations with and summer rainfall in China exhibit and turbulence from the GADS jet. observations. However, ERAI reanalysis obvious biennial rhythms as revealed by data set They are also consistent with conclusions performed better than other reanalysis time coefficient of the leading EOF mode. Author Joel Tenenbaum of Delcambre et al. (2014) for doubled data, even if the selection of reanalysis When summer VIMF is strong (weak) in SUNY Purchase CO2: that the wind speed for the jet exit data for WRA still depends on the the south Asia monsoon region, a dipole Affiliation region shows a strengthening and the location of site. VIMF anomaly in the East Asia – western Co-authors North Pacific is propitious to negative P. D. Williams (University of Reading, core shows a weakening. The trends in (positive) VIMF convergence anomalies Reading, UK) “light” turbulence are less clear, because in the middle and lower reaches of the rarity of turbulence and the large the Yangtze River and the Yangtze- The North Atlantic jet stream is important interannual variability demands a longer Huaihe valley but positive (negative) for aviation, influencing flight routes, data set to expose any secular trends. VIMF convergence anomalies in South journey times, turbulence, and possible Our primary results are independent of China and North China, which result in effects of climate change. This study computer models. a meridional tripole structure of rainfall used a dense set of aircraft observations anomalies in eastern China, i.e., droughts relative to the Aircraft Meteorological
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 120 Section 5
Finally, the spatial structure of the four forecasting system in several points in and a modelled value for the melt water Intercomparison of monthly weather regimes has been related to the Persian are compared and the reason production. The evaluation of different Euro-Atlantic weather regimes the four main monthly teleconnection of differences are investigated. melt variables reveals that different years obtained from different patterns in the Euro-Atlantic region (NAO, will be identified as years of extreme melt reanalysis and of their influence EA, EA/WRUS and SCAND) obtained depending on how melt is quantified. from the same reanalysis. Results Number of melt days and Our study includes a comparison on wind energy resources confirm the usefulness of the monthly atmospheric conditions in between the ice surface temperature classification for the characterisation of Greenland in 2000-2014 Author Nicola Cortesi of the MODIS product and ERA- the monthly wind speed variability over Affiliation Barcelona Author Ilona Välisuo Interim surface temperature. ERA- most part of Europe. Supercomputing Center Affiliation Finnish Meteorological Interim’s surface temperature is found (BSC) Institute to be mostly warmer than MODIS IST. However, the difference in the Co-authors Marine Forecasting Systems Co-authors temperatures is smaller when the Nube González-Reviriego, Veronica in Caspian Sea, Persian Gulf T. Vihma (Finnish Meteorological temperatures are close to the melting Torralba, Albert Soret, Francisco Javier and Oman Sea Institute), R. Pirazzini (Finnish point. Doblas-Reyes Meteorological Institute), M. Schäfer Author Alireza Vaselali For wind energy companies, it is crucial (Finnish Meteorological Institute) We study the weather conditions in Affiliation Behin Tarhe Appadana March-May and June-August separately to identify the main sources of wind Surface melt on Greenland ice sheet (BETA Group) to understand which kind of atmospheric speed variability affecting their wind and extremely warm temperatures in the Co-authors conditions occurred in the early stage farms, at all time scales. It is known that Arctic since 2007 have been linked to Aliasghar Golshani (Met Ocean Expert, of the melt season, as well as during changes in the frequencies of occurrence negative North Atlantic Oscillation (NAO) Beta Group Consulting Engineers), the strongest melt. Our interest is of the monthly Euro-Atlantic weather in numerous studies. Cases of extreme Said Mazaheri (Research Assistant especially in the surface temperature, regimes determine most of the variation melt on Greenland are also related to Professor, Iranian National Institute for near surface wind, total cloud water of wind speed anomalies over Europe anticyclonic circulation centered over Oceanography and Atmospheric Science) content and atmospheric pressure. The (Hannachi et al., 2017). Greenland, which favours warm-air meteorological variables are retrieved There are several global marine forecast advection to Greenland. Firstly, the impact of the monthly from ERA-Interim and NCEP-CFSR systems based on large scale regional frequency of the four main monthly We investigate the connections between reanalyses. data covering Iranian seas which are weather regimes on 10-m wind interannual variations of the number of freely available on their websites. They speed variability over Europe has melt days on Greenland ice sheet and are also several local marine forecast been evaluated. Subsequently, an atmospheric and surface conditions in systems in Iranian waters. This paper intercomparison of the spatial patterns 2000-2014. We calculate the number performs an inter-comparison among and frequencies of the monthly weather of melt days using a MODIS based different marine forecasting systems regimes derived from daily sea level product on ice surface temperature. in Iranian seas in order to evaluate the pressure data during last 35 years has As the spatial coverage of the MODIS accuracy and difference between them been performed for three different product is limited, we complement it with and give a proper ground for further reanalyses: JRA-55, ERA-Interim and ERA-Interim surface temperature. To investigation and research in this crucial NCEP/NCAR. quantify melt, we use also satellite based issue. For this purpose, the results of two maximum and cumulative melt extent,
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 121 Section 5
Our assessment of the influence of The data support team at GES DISC, challenge for users to download what On the sensitivity of Antarctic forcing inaccuracies on the simulated working closely with the MERRA-2 they need. For example, extracting one sea ice model biases to Antarctic sea ice allows disentangling the science team, has created value added parameter at a single point for 30 years atmospheric forcing model biases that can be reduced thanks data tools and provided high quality may take over 15 hours. Moreover, users uncertainties to better atmospheric forcings from those services to the broad user community. wish to have such a long time series in a that would require improvements of the MERRA-2 subsetter is a powerful single file. Author Antoine Barthélemy physics of the ice or ocean model. data tool for downloading selected The GES DISC is exploring methods parameters, region, and time. Affiliation Université catholique for the improvement of accessing big de Louvain Online Visualization and Value One function is, with a number of model data. One approach attempts to Co-authors Added Services of MERRA-2 interpolation methods, to regrid the optimize file structure. Initial performance Hugues Goosse (Université catholique Data at GES DISC spatial resolution to models, such as tests of year-file of hourly data have de Louvain), Thierry Fichefet (Université ERA, cfsr, GEOS, GLDAS, etc., and to shown dramatic improvement of the catholique de Louvain), Olivier Lecomte Author Suhung Shen save the data in a different format. In accessibility. (Université catholique de Louvain) Affiliation George Mason University addition, the interoperable services, such & GES DISC NASA as OPeNDAP and GDS are provided Although atmospheric reanalyses are for remote accessing data via using Reanalyses.org: Advancing user Co-authors an extremely valuable tool to study the applications such as Matlab, GrADS, R, and producer needs for Dana M. Ostrenga (ADNET and NASA), climate of polar regions, they suffer from IDV, etc. Selected MERRA-2 parameters reanalysis with services and Bruce E. Vollmer (NASA), Mahabaleshwa large uncertainties in these data-poor have been integrated into Giovanni, an S. Hegde (ADNET and NASA), Jennifer tools areas. In this work, we examine how online visualization and analysis system C. Wei (ADNET and NASA), Michael G. Antarctic sea ice biases in an ocean-sea developed in-house at GES DISC. Author Catherine A. Smith Bosilovich (NASA) ice model are related to these forcing Affiliation NOAA/ESRL PSD Giovanni has more than twenty uncertainties. NASA climate reanalysis dataset from & CU CIRES visualization functions that enables MERRA-2, distributed at Goddard Earth Three experiments are conducted in easy and quick exploration of data by Co-authors Sciences Data and Information Services which the NEMO-LIM model is forced performing basic statistical analysis G.P. Compo (NOAA/ESRL PSD Center (GES DISC), contains numerous by different atmospheric forcing sets. and comparisons between variables. and CU CIRES) data for atmosphere, land, and ocean, The minimum ice extent, the ice drift For example, it generates maps with that are grouped into 94 products of The University of Colorado/CIRES and and the ice thickness are sensitive to the user defined time range and is able to archived volume over 333 TB. The data NOAA/ESRL Physical Sciences Division reanalysis chosen to drive the model, adjust the color scales for best showing files are saved as day-file and month- host two types of support for users and while the wintertime ice extent and inner interested signals. It generates time file for hourly and monthly time interval producers of reanalysis datasets. The pack concentrations are barely affected. series for a single point, an area, a respectively. first is the website “Reanalyses.org”. The analysis of sea ice concentration political boundary, such as countries, or Using a collaborative Wiki framework, budgets allows identifying the processes Each product contains parameter a water shed. the goal of reanalyses.org is to facilitate numbers varying from 2 to 125. Due leading to differences between the Application research studies concerning comparison between reanalysis and to the large number of products, data experiments, and also indicates that renewable energy, extreme weather, and observational datasets. files, and data volumes, it is a challenge large and similar errors compared to air quality, etc. require long-term data at for users to find and download the only observations are present in all three high temporal resolutions. With native parameters and spatial region of interest. cases. file structure of the hourly data, it is a
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 122 Section 5
To accomplish this, reanalyses. available. A full set of statistics is output. numbers and Accumulated Cyclone org is divided into reanalysis types: The 3rd tool, WRIT Distributions, can Energy (ACE) over the 135-year period Risk and vulnerability analysis in Atmosphere and Ocean (with Land to be used to examine the distributions of from 1878 to 2012. Madagascar using AHP method come). Each type includes webpages daily data from several reanalysis and We find that these fields replicate that describe the datasets, provide observed datasets. Author Tsiory Rakotoarison historical hurricane activity surprisingly references, help users obtain the data, Affiliation EMIT University Users can compare distributions to well, showing that contemporary directs users to plotting and analysis of Fianarantsoa each other and to a set of provided statistical models and their seasonal tools for the data, and provides a place distributions. The 4th tool, WRIT physical links have long-term robustness. Co-authors for researchers to describe their research Trajectory, allows users to plot We find that August-September zonal Aimé Richard Hajalalaina (Ecole using the reanalyses. atmospheric trajectories from several trade wind speed over the Caribbean de Management et d’Innovation Pages can be edited by validated users. reanalysis datasets using 4x-times daily Sea and the tropical North Atlantic is the Technologique, Université de Anyone can post a comment on most pressure level data to calculate the path environmental field which individually Fianarantsoa, Madagascar) pages with experts available to answer of tracer particles. replicates long-term hurricane activity The major hazards, namely cyclone, questions. The pages are searchable and the best, and that trade wind speed flood and drought, occur frequently indexed. There are even “private” areas combined with the difference in sea Replicating Annual North and periodically in Madagascar. for groups such as the WCRP Task Team surface temperature between the tropical These extreme phenomena cause for the Intercomparison of ReAnalyses Atlantic Hurricane Activity Atlantic and the tropical mean is the best direct mortality, flooding, damage to (TIRA) to collaborate. To the Tools area 1878-2012 from Environmental multi-predictor model. infrastructure such as roads, schools, of Reanalyses.org, CIRES and PS have Variables Comparing the performance of the best health centers and population centers, as contributed the “WRIT” or Web-based single-predictor and best multi-predictor well as crop destruction and landslides. Reanalysis Intercomparison tools at Author Philip Klotzbach models shows that they exhibit little Disasters hamper development programs https://www.esrl.noaa.gov/psd/data/writ/. Affiliation Colorado State University difference in hindcast skill for predicting and result in loss of people’s property There are currently four tools available. Co-authors long-term ACE but that the best multi- that leads to a decline in the economic In the Writ Maps Tool, one can plot Mark Saunders (Mullard Space Science predictor model offers improved skill for level. Risk and vulnerability analysis is maps and cross-sections from monthly- Laboratory, University College-London) predicting long-term hurricane numbers. a necessary part of decision-making mean fields of reanalysis datasets. One Adam Lea (Mullard Space Science We examine whether replicated real-time on risk and disaster management. can also plot the difference of any two Center, University College-London) prediction skill 1983-2012 increases as In addition, spatial decision-making problems are multicriteria nature. For this datasets. Users can examine means, Statistical models can replicate annual the model training period lengthens and purpose, the multicriteria hierarchical anomalies, or climatologies using North Atlantic hurricane activity from find evidence that this happens slowly. different seasons and sets of years. analysis (AHP) method was applied large-scale environmental field data for We identify a dropout in hurricane Some other observational datasets are to ERA-Interim reanalysis data from August and September, the months of replication centered on the 1940s and provided for comparison. The 2nd tool, ECMWF coupled with cyclonic data peak hurricane activity. We assess how show that this is likely due to a decrease WRIT Timeseries, allows users to plot and socio-economic data, in order to well the six environmental fields used in data quality which affects all data sets similar datasets but instead compare break down the complex problem into most often in contemporary statistical but Atlantic sea surface temperatures in gridpoint or area-averaged time-series. a structure Hierarchical analysis for modeling of seasonal hurricane activity particular. Finally we offer insights on the Users can plot and/or compare time- risk analysis and vulnerability to major replicate North Atlantic hurricane implications of our findings for seasonal series, specifying the region or season. hazards in Madagascar. hurricane prediction. Land/ocean masking functionality is
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 123 Section 5
to complete the data. Quality control data throughout of ASEAN and a part of SACA&D gridding data as a tool in SACA&D is using homogeinity test from Pacific. There are 3 step methods of Southern hemisphere low- for climate monitoring and Wijngard to clasify the data is usefull, SA-OBS, one of the method is an frequency troposheric information services for the doubfull and suspect. The other methods interpolation of monthly mean/total using circulation components and Asean and Pacific Region are called blending and non blending to thin plate splin to define the spatial trend, their contribution to river runoffs extend the period of climate data. daily anomalies using global kriging with Author Sunaryo Naryo a single variogram for all days. changes in Central Eastern Meta information for the daily series Patagonia Affiliation BMKG Indonesia is provided methode both for the Climate information and monitoring blanded and non blended series. The product of SA-OBS are daily maps for 4 Author Eduardo A. Agosta SACA&D is a Website visualisation of blended series have been tested for elements TN, TX, TG and RR closely of UCA/CONICET/FCAGLP the climate dataset for the ASEAN and Affiliation homogeneity, which is relevant to assess the ASEAN and Pacific region. Benefits Pacific region. Co-authors the quality of each series for climate of the SACA&D gridding data is the R.A. Maenza (Grupo de Geología de SACA&D is a part of ICA&D (International change information. To get the climate monitoring extreme events in the region Costas y Paleoecología, Instituto de Climate Assessment and Dataset) monitoring and information services in when La Nina and El Niño year and its Investigaciones Marinas y Costeras network which is consist of WACA&D the ASEAN and Pacific region, there are impact like as drough, flood, forest fire. In (IIMYC-UNMDP-CONICET)), D.C. (West Africa), LACA&D (Latin America), available in 44 indices included trends, the National level, BMKG has developed Araneo (Facultad de Ciencias Exactas y SACA&D (Asean and Pacific) and ECA&D changing probabilities of high impact the climate data online services Naturales (FCEN), Universidad Nacional (Eropean) to get access of SACA&D extremes like as droughts, floods, health included gridding data and Indonesia de Cuyo (UNCuyo), CONICET). website is http://sacad.database. risk, inparticularly of food security, has implemented the data policy by bmkg.go.id. Agency of Meteorology, energy, transportation and others. Indice WMO resolutions 60 and followed by Patagonia is under influence of the Climatology and Geophysics of Indonesia extremes are available in form of time Goverment regulation that the cimate westerlies that drive the amount and Jakarta (BMKG) has managing this series plot, trend maps, anomaly map data is free charge for public. distribution of precipitation in the Website and it has launched in the event index, climatology maps for this region. Southern Hemisphere (SH) middle of the Second International Workshop latitudes. Two sub regions with highly Data Gridding of the SACA&D developed of SACA&D on April 2012 in Bogor distinct precipitation features are: wet between KNMI Holland and BMKG to Indonesia. SACA&D plays an important Western Patagonia, from the Pacific increase the Climate monitoring and role in climate information and monitoring coast to the Andean highs; and dry information services namely SA-OBS in the region especially for the ASEAN Eastern Patagonia, leeward the Andes in Version1.0 and It had used effectively and pacific region. It’s built of the the Argentine steppe plateau towards the in 2016 until now. SA-OBS made with cooperation between BMKG Indonesia Atlantic. regular grid 0.25o and 0.50o With and KNMI Holland in supported by 10 coverage area all ASEAN country The cold season (Apr-Sep) is the rainy ASEAN member countries, and 6 others between 25o North to 25o South and season over the mountains in central countries in the Pacific region included of from 80o East to 180o East and available Patagonia (40°S-50°S), leading to snow Australia. All 16 countries has contributes in NetCDF format. SA-OBS consist of 4 accumulation over river catchment areas. a climate daily observation data with 10 parameters of daily value for TX, TG, TN The winter snow feeds river runoffs to parameters and synoptic data which and RR with period data from 01 January the east in EP. The Tecka-Gualjaina (TG) is GTS exchanges data every 3 hourly 1980 to 31 Dec 2014. Station density River is one of those which drain their and other source data from GHCN and of this RR is 5979 series observations streamflow into the South Atlantic, from ECMWF data model as a comparison and
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 124 Section 5 the Andes to the Atlantic. We explored the SST anomalies, show significant slow However, due to the availability of fractal dimension indicates the property influence of tropospheric circulation and components consistent with the trend radar data, COSMO-REA2 only covers of self-similarity, and in the case of sea surface temperature (SST) anomalies and changes in the TG streamflow. the period from 2007-2013. In our this study, wherein it is applied to the on the interannual-to-decadal streamflow Trends in tropospheric fields during the downscaling approach, we use the temporal behaviour of rainfall at a fine variations of the TG River for the season river peak season are present even if analog ensemble technique to generate (10-minute) resolution from a total of 44 of maximum streamflow (Jun-Nov) and inhomogeneities are removed. synthetic time series of 2D precipitation observatories, it provides insights into its the season of minimum streamflow (Dec- fields for earlier time periods. Here, we more or less convective nature. May). The maxima show negative trend use the 20-year (1995-2014) data set The methodology of Jenkinson & Collison along records. There is a change in the Statistical Downscaling of 2D COSMO-REA6 at 6km resolution as which automatically classifies synoptic streamflow anomalies by the early 1980s, Reanalysis Fields with the predictor. situations at the surface, as well as evolving from a positive predominance Analog Ensemble The probabilistic estimates for the an adaptation of this methodology at before to a negative one after. Author Jan D. Keller precipitation are created by finding analogs 500 hPa, were applied in order to gain The minima show stationarity (no trend). Affiliation Hans-Ertel-Centre for in the existing COSMO-REA2 data set for insights into the synoptic implications of The intra-decadal quasi-cycles are Weather Research each time step in the reconstruction period extreme values of the fractal dimension. dominant in both seasonal streamflow (1995-2006). The analogs are determined The highest fractal dimension values in Co-authors maxima and minima. Teleconnections as the N best matches in terms of a metric the study area were observed in places L. Delle Monache (National Center for related to the streamflow were analyzed calculated using COSMO-REA6. These with precipitation that is more random Atmospheric Research, Boulder, USA), using ERA-Interim, NCEP/NCAR I, 20C, analog ensembles are then validated over time with generally high totals. S. Alessandrini (National Center for and ERA-20C reanalysis datasets and against independent observations over Atmospheric Research, Boulder, USA) Four different regions in which the other oceanic and atmospheric global central Europe. atmospheric mechanisms giving rise datasets. Detrended streamflow maxima Reanalyses provide a valuable source to precipitation at the surface differ are linked to a quasi-stationary Rossby of information on meteorological from the corresponding above-ground wave (QSW). parameters as retrospective time Synoptic implications at sea mechanisms have been identified in series. In order to exploit these data, a level pressure and 500 hPa Tropospheric circulation anomalies, the study area based on the fractal statistical downscaling approach can of the temporal fractality of symmetric about the equator, are dimension. In the north of the Iberian be applied. Such an approach acts as possibly associated with tropical precipitation according to the Peninsula, high fractal dimension a correction of systematic errors in the convection, induced by anomalous SST ERA-Interim reanalysis products values are linked to a lower frequency reanalysis with respect to the parameter in the equatorial western Pacific. The of anticyclonic situations, whereas the (predictand) in consideration. Reanalysis Author Oliver Meseguer-Ruiz QSW affects the position and intensity opposite occurs in the central region. intercomparison has shown the value Universidad de Tarapacá of the subtropical and polar jets, Affiliation of using very high model resolution In the Mediterranean, higher fractal altering winter precipitating transient Co-author combined with the assimilation of radar dimension values are associated with a perturbations. Detrended streamflow P. Sarricolea (Departamento de Geografía, data with respect to the representation higher frequency of the anticyclonic type minima are linked to a high latitude Universidad de Chile) of precipitation in the regional reanalysis and a lower frequency of the advective annular mode-like variability, modulated COSMO-REA2 at 2km horizontal Precipitation on the Spanish mainland type from the east. In the south, lower by a mid-latitude wave-3 structures resolution (Wahl et al. 2017). and in the Balearic archipelago exhibits fractal dimension values indicate higher over the Pacific and Atlantic. Trend a high degree of spatial and temporal frequency with respect to the anticyclonic analysis and inhomogeneity tests on variability, regardless of the temporal type from the east and lower frequency SH tropospheric circulation fields and resolution of the data considered. The with respect to the cyclonic type.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 125 Section 5
information sector and science users. In this work we are interested in the means and 12 month running means. The C3S Climate Monitoring This presentation will give an overview numerical modeling of marine currents, The post for each month includes a Facility and demonstration of this online which allows us to describe their short discussion about the salient points monitoring tool. direction and speed on the studied relevant to that month and ECV. Author Iryna Rozum area. Our contribution to this work was The list of ECVs considered, to date, Affiliation ECMWF made using the SWAN digital model. is surface air temperature, sea-ice, The characterisation of the The characteristics obtained will be Co-author precipitation, surface humidity and soil marine renewable energy presented in the form of maps or tables Hans Hersbach (ECMWF) moisture. This presentation will show resource (currents energy), of values. some of the recent highlights from this On behalf of the European Commission, on a Moroccan coastal zone ECMWF operates the Copernicus climate monitoring, including the record Climate Change Service (C3S). C3S using SWAN model The contribution of reanalysis high global surface air temperatures combines climate observations with the Author Hazim Salma to climate monitoring experienced during 2015 and 2016 latest science to develop comprehensive, and illustrated by ERA-Interim. Affiliation Mohamed V University/ quality-assured information about the Author Berrisford Paul IRESEN past, present and future state of the Affiliation ECMWF & NCAS Climate Co-authors The Mediterranean Climate Earth’s climate. As part of this service a Co-authors Hazim Salma (1,2), Benazzouz Aissa (3), Modes: their seasonal variability, web-based tool is developed that allows D. Dee (ECMWF), H Hersbach (ECMWF), Ghuennioui Abdellatif (2), El Ouatouati users to interactively browse, visualise, J. Munoz-Sabater (ECMWF), E. Remete impacts and predictability from Ahmed (1), Taha Janan Mourad (1), Naimi analyse and compare time series for (ECMWF), I. Rozum (ECMWF), A. Simmons renalysed fields. essential climate variables (ECVs) from Zakaria (2), Badr Ikken (2). 1: Mohamed (ECMWF), J-N Thepaut (ECMWF) Author OrtizBeviá Maria J. various sources as they become available V University, 2: Institut de Recherche en in the C3S Climate Data Store (CDS). Energie Solaire et Energies Nouvelles The Copernicus Climate Change Service Affiliation University of Alcala (IRESEN) 3:Institut supérieur d’études (C3S) includes in its product portfolio, Co-authors This includes ECVs directly obtained maritimes ISEM reanalyses and a climate monitoring Ruizde Elvira A. (University of Alcalá), from satellite data (such as from facility. These two products are being Due to its geographical position, Alvarez-García F. J. (University of Alcalá) ESA’s Climate Change Initiative, and used to monitor the climate by providing Morocco has a great renewable energy operational products from C3S providers) monthly updates on the climate for The Mediterranean region variability resources potential, especially the Marine and reanalysis (such as ERA-Interim several ECVs. The monthly updates are is characterised by several regional Renewable Energy (MRE/EMR). It has and ERA5). An associated event data posted onto the Copernicus website Climate Modes. Some among these, as 2 seas: Mediterranean and Atlantic base displays relevant metadata to within a few days of the end of each the Western and Central Mediterranean seas, this last one is characterized by assist users to correctly interpret and month. Currently, the main sources of Mode (WMM) or the Mediterrenean its predictability and potential that is not understand results (including natural content are the ERA-Interim and ERA5 Dipole Mode (MDM), are characterised exploited yet. The aim of this work is the events such as volcanic eruptions and global reanalyses. from indexes obtained from the data events such as changes in the characterisation of the marine renewable Mediterranean SST anomalies. Others, global observing system). energy resource, more precisely the The content varies depending on the as the Mediterranean Oscillation (MO) or marine currents, on a Moroccan coastal ECV, but typically includes global and the Western Mediterranean Oscillation The CMF will form an integral part of zone; the Terfaya zone, with a spatial European maps of anomalies for the (WMO), are monitored from indexes the CDS toolbox and will serve a wide resolution of 200m. month and the last year and global obtained from atmospheric (SLP) fields. range of users including the sectorial and European time series for monthly
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In the work to be presented we compare To represent the zonal mean fields, the Subtropical High (NPSH) over East Asia the characteristics of these modes mass-weighted isentropic zonal mean Trends and Tele-connections by about 5-70 of longitudes. obtained from different Reanalysed (MIM) Method (Iwasaki 1989) is applied among South and East Asian While the west Indian Ocean SSTs fields (ERA-40, Had ISST2 in one case to JRA-55. The MIM method is suitable Monsoons: Evidences through appear to be related with summer NCEP, ERA-40 and ERA-20C in the for the examination of zonal momentum NCEP-NCAR and CMIP5 Data monsoon rainfall over northern parts other also compare their impacts on the budget, and enables analysis of a single of India and North China, and may be precipitation and the temperature fields hemispheric cell, such as Blewer-Dobson Author Ramesh Kripalani instrumental in the decreasing trend of the neighbouring regions (CRU and circulation in the stratosphere and the Affiliation Indian Institute of Tropical in the summer monsoon rainfall over U Delaware reanalysis). We also identify extra-tropospheric direct circulation. Meteorology northern parts of India and over North potential predictability fron the seasonal In order to extract variability synchronized Co-authors China, SSTs over the West Pacific Ocean teleconnections of these modes with the with BSISO or lower (higher) frequent M. Mujumdar (Indian Institute of Tropical (WPO) appear to be related with summer midlatitudes or tropical variability. variability than BSISO, temporal filtering Meteorology), A.Prabhu (Indian Institute monsoon rainfall over southern parts of based on Duchon (1979) is also carried out of Tropical Eteorology) India and over South Korea-Japan sector. to the zonal mean fields obtained by the The Relationship between Boreal Recent trends and tele-connections Thus the increasing trends over these application of the MIM method. We found summer Intra-seasonal in the summer monsoon rainfall over regions may be related with SSTs over some characteristic features of the zonal Oscillation and the Stratospheric South and East Asia are examined for the WPO. Outputs from the Coupled wind field during the significant BSISO: the observational period 1970-2014. Model Inter-comparison Project Phase 5 Circulation Hemispherically symmetric westerly Trend analysis indicates that over (CMIP5) are investigated using historical anomalies are observed from mid- Author Yayoi Harada South Asia one contiguous region over simulations (1861-2005) and future troposphere up to the tropical tropopause Affiliation Meteorological Research northern part India exhibits a significant projections (2005-2100) under the RCP4.5 layer (TTL) just after the northward Institute/Japan decreasing trend and another region scenario. In spite of large spread among migration of active convective region in meteorological Agency over the southern part of India exhibits the CMIP5 models, future projections in BSISO region, and move poleward in a significant increasing trend in the the summer monsoon rainfall over South both hemispheres in spite of meridional Boreal summer intra-seasonal oscillation summer (June through September) as well as East Asia indicate a multi- asymmetry of the convective activity: (BSISO) is a phenomenon that active monsoon rainfall. decadal variability, displaying certain In the extra-tropical upper stratosphere convective region migrate northward in epochs of more rainfall over South Asia of the Northern Hemisphere, both However over East Asia two regions the Indian Ocean and the western Pacific than over East Asia and vice versa. with a period of 30 – 90 days. In this easterly anomalies and positive potential one over the Korea-Japan peninsula study, statistical relationships between temperature anomalies are statistically and another over South China indicate a Tele-connections between the South and BSISO and the stratospheric circulation significant during the northward migration significant increasing trend. Incidentally, East Asian monsoon rainfall also exhibits are examined focusing on the variabilities of active convective region. the summer monsoon rainfall over North a multi-decadal variability with alternate China also indicates a decreasing trend. epochs of strengthening and weakening of the zonal wind fields both in the Moreover, our results also reveal that Furthermore analysis of SSTs, MSLP and relationship. Furthermore large-scale troposphere and stratosphere. BSISO the amplitude of BSISO is extraordinarily winds at lower troposphere indicates that circulation features such as the monsoon index based on Kikuchi et al. (2012) and large during the strong low-frequency the entire monsoon flow appears to have trough over South Asia and the NPSH the Japanese 55-year Reanalysis (JRA- easterly anomalies at around the 20 shifted westwards, with the low pressure depict an oscillatory behavior with east- 55, Kobayashi et al. 2015) are used for hPa level associated with quasi-biennial monsoon trough over South Asia by 2-30 west-east shifts, probably suggesting composite analysis. oscillation (QBO) and suggest influence of longitudes and the North Pacific that the recent trends may be a part of of the stratospheric circulation on the natural climate variability activity of BSISO in the troposphere.
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We will carry out spatial and temporal Andreas Hense (Meteorological Institute, The high resolution reanalyses COSMO- Use of reanalyses in climate analyses, as well as inter-variable University Bonn, Germany), Susanne REA6 (6 km horizontal resolution, 40 monitoring and research for correlation analyses of ERA5 data Crewell (Institute of Geophysics and vertical layers) and COSMO-REA2 (2 km the cocoa industry compared to NCEP/NCAR during Meteorology, University of Cologne, horizontal resolution, 50 vertical layers) harmattan season over West Africa for Germany) are based on the operational numerical Author Alina Gainusa-Bogdan multiple harmattan-related variables weather prediction model COSMO. REA6 The ongoing energy transition causes Affiliation Rockwinds (relative humidity of air near the surface, covers Europe and the Mediterranean major challenges for many stakeholders wind velocity and the difference between region (CORDEX EUR-11 domain), REA2 Co-author due to the spatiotemporal inhomogeneity daily minimum and maximum near- is limited to Germany and its neighboring A. Diedhiou (National Research Institute of renewable energy sources: (1) The surface temperature). For variables regions. for Sustainable Development (IRD), transition system operator is challenged affecting cocoa crops all throughout France) to ensure the balancing between The coarser reanalysis is available for the year, like temperature, soil humidity energy supply and energy demand. two decades from 1995 to 2014 and the Providing gridded, global coverage and precipitation, analyses will span (2) The distribution system operator finer from 2007 to 2013. Both reanalyses over long, uninterrupted periods of the full time series and, in the case of is challenged to provide the required are generated with a nudging scheme to time for a wide array of variables with precipitation, other, gauge and satellite- infra structure from centralized to de- assimilate observations. In this quality physically-consistent fields, reanalyses based data sets will be considered for centralized electricity generators. (3) The assessment, independent observations are an extremely valuable source of comparison. data for operational climate monitoring spot market participants are challenged of global radiation provided by the and applied research for the agricultural by dealing with volatile energy supplies. Baseline Surface Radiation Network sector. The cocoa trading company Validation of COSMO-REA6/2 In order to overcome these problems it (BSRN) are used. For wind speed Rockwinds has been using the NCEP/ in respect to renewable energy is crucial to know where, when and to evaluation 10m above ground SYNOP NCAR reanalysis to monitor and gain applications what extent renewable energy can be observations serve as verifying “truth”. new insights into the development of generated. Vertical wind profiles are compared to Author Christopher Frank measurements from two meteorological the harmattan over West African cocoa Atmospheric reanalyses offers masts in Jülich and Hamburg (Germany). regions over the last three harmattan Affiliation Hans-Ertel-Centre for interesting opportunities for a posteriori seasons in order to better predict the Weather Research & studies, since they provide all relevant The evaluation shows that while subsequent evolution of African cocoa University of Cologne meteorological quantities in a gridded the regional reanalyses have some crops. Co-authors and consistent way. Especially, high- deficiencies, they show significant Besides numerous merits, the NCEP/ Sabrina Wahl ((Hans-Ertel-Centre resolution reanalyses with gird sizes of improvements for radiation and wind NCAR operational product also has some for Weather Research, Climate a few kilometers allow detailed studies speed scale dependent correlations drawbacks, one of the most obvious Monitoring and Diagnostics, Germany), on small scale variability. Therefore, compared to global reanalyses such ones being its coarse spatial resolution, (Meteorological Institute, University Bonn, we provide an evaluation of regional as ERA-Interim. of major concern for analyses targeting Germany)), Jan D. Keller ((Hans-Ertel- reanalyses with respect to renewable the relatively narrow African cocoa belt. Centre for Weather Research, Climate energy related quantities such as wind It is thus with great interest that the Monitoring and Diagnostics, Germany), speed and solar energy. (Deutscher Wetterdienst, Offenbach, release of several years of the new, high- This work focuses on two high resolution Germany)), Bernhard Pospichal (Institute resolution ERA5 data is expected in June reanalyses developed within the Hans- of Geophysics and Meteorology, 2017. Ertel Centre for Weather Research of University of Cologne, Germany), the German Weather Service (DWD).
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 128 Section 5
Science Research Program through the In this work, we describe the six- statistically characterize the resource in Variations of drought index with National Research Foundation of Korea week climate outlooks developed and specific sites, therefore the use of high- different reference periods funded by the Ministry of Science, ICT & tested in the CLIPS project during the resolution wave models is mandatory. Future Planning (2015R1C1A2A01054800) summer season 2017 and show the first Wave models of third generation are Author Myoung-Jin Um Keywords Drought Characteristics, verification results. based on the evolution of the two- Affiliation Yonsei University Reference Period, SPEI dimensional wave spectrum, defined Co-authors Wave resource assessment in each grid point of the model, that is Y. Kim (Yonsei University), Verification of six-week function of wave frequency and direction. D. Park (Konkuk University) for the development of wave forecasts in Finland with energy sector Waves are forced by surface wind The objective in this study is reanalysis data stress and, in open boundary regions, understanding how much the drought Author Gianmaria Sannino depend also on the propagation of waves indices are changed due to the different Author Natalia Korhonen Affiliation ENEA originated from outside the region. reference periods. We focused on the Affiliation Finnish Meteorological Co-authors In this case, in order to perform wave effects of drought characteristics, such Institute A. Carillo (ENEA), M.V. Struglia (ENEA) simulations, besides surface forcing as trends and frequency, for historical Co-authors represented by wind components, the The growing interest in the Blue Energy periods (1901-2014) with the standard O. Hyvärinen (Finnish Meteorological entire spectra of incoming waves along sector represents an opportunity for precipitation evapotranspiration index Institute), T.K. Laurila (Finnish the boundaries are needed. In this work the sustainable growth of maritime (SPEI) and used the datasets of the Meteorological Institute), A. Vajda (Finnish we present a very high-resolution wave economies, the sustainable development climate research unit (CRU) and the Meteorological Institute), H. Gregow resource assessment in a region of the of marine areas and the sustainable University of Delaware (UDEL). (Finnish Meteorological Institute) Mediterranean Sea, forced at the surface use of marine resources. Among them and laterally by ERA-Interim reanalysis. We chose the three cases of reference Since June 2017, novel six-week climatic the wave energy sector can play an The 10-year simulation has been periods, such as Ref 1 (1901–2014), Ref forecasts are produced operationally important role in the clean energy performed using SWAN (Simulating Wave 2(1901-1957 and 1958–2014) and Ref 3 at the Finnish Meteorological Institute economy, as it is very abundant, diffuse Nearshore) model. (1901-1957) and estimated the SPEI to (FMI) in CLIPS project (CLImate services and renewable. investigate the statistical differences. supporting Public activities and Safety, Its exploitation is based both on We found that drought characteristics, http://clips.fmi.fi/?lang=en). The main technological research aimed to the particularly the severity and spatial emphasis is to support the Finnish development of new efficient devices, extent, were different depending on the public in planning their activities by and on the accurate assessment of reference periods. Although we used only co-designing and piloting the products the resource. In this view, a complete two global datasets (CRU and UDEL), we together with the end-users community. statistical characterisation of waves is suggest that the reference period should It is clear that the provision of usable essential both to optimize the design of be carefully chosen to estimate the forecasts especially at high-latitudes the wave energy converter devices and statistical drought indices. is a challenging task. To examine the to estimate in advance the productivity accuracy and usability of the developed Acknowledgement This study was of a site. Available observations, either products, essential part of the work is supported by the Korea Meteorological buoys or satellites, are inadequate to Administration R&D Program under the verification of the forecasts for which Grant KMIPA 20156180 and by the Basic the ECMWF reanalysis data plays an important role.
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 129 Section 5
world’s wind resource ant to produce the model data production and preliminary World Bank New Global Wind global mesoscale layer of wind and other results of the validations of the global Atlas project powered by meteorological variables. 3km resolution wind resolution based in ERA Interim and ERA5 (reduced sample) Copernicus Reanalysis A further downscaled will be conducted downscaling. Author Gil Lizcano by DTU to under the kilometre resolution using and WAsP model and derived Affiliation Vortex generalized wind climatologies. The Co-authors atlas will have an interim version to be O. Lacava, (Vortex), P. Casso, (Vortex), released in November 2017 which will A. Bosch, (Vortex), A. Hahmann, (DTU), be built using ERA Interim Reanalysis as J. Badger, (DTU), R. Whiting, (Everoze) large scale conditions. The final version Good wind data is critical to getting which is scheduled to go live by the end more wind projects built, and in turn of 2018 will incorporate ERA5 Copernicus helping to ensure access to affordable, Climate Change Service (C3S) Reanalysis reliable, sustainable and modern energy as drivers. for all. With this intention, World Bank The modelling will seamlessly interact (WB), through the ESMAP program, with the existing GWA, helping develop launched several initiatives to improve a free access wind resource tool. At access to quality of wind and solar the same time the data will deliver real resource information and, hence, to change on the ground, helping policy boost new renewable energies markets makers and project developers in in developing countries. As part of developing countries get projects built. this effort, a global wind atlas master plan has been designed by the WB in The engagement will also see the partnership with Danish Technology consortium deliver a wide spectrum of University (DTU). development support in a number of emerging economies, from country- The project will update existing DTU level analysis and wind development Global Wind Atlas (GWA) with an zone identification through to individual improved modeling stream which will bankable site assessment and due incorporate latest Reanalysis datasets diligence review. and a complete mesoscale model downscaling. The new GWA project will The presentation will provide a undertake a global level meso-scale description of the methodological modelling to 3km resolution which will approach based on the use reanalysis be be achieved with WRF atmospheric and mesoscale modeling technology modelling stream. Mesoscale modellers and status of the project development. Vortex will be responsible to map the Focus will be given to the mesoscale
ECMWF | 5th International Conference on Reanalysis (ICR5) 2017 130 5th International Conference on Reanalysis (ICR5) 13–17 November 2017, Rome
Copernicus ECMWF Email: [email protected] European Centre for Tel: +44 118 949 9000 Medium-Range Weather Forecasts atmosphere.copernicus.eu climate.copernicus.eu Shinfield Park ecmwf.int Reading copernicus.eu RG2 9AX United Kingdom @CopernicusECMWF