Arctic requirements for high resolution reanalysis
Harald Schyberg Thanks to: Jun She (DMI), Malte Müller (MET Norway), Trond Iversen (MET Norway)
h.schyberg
Norwegian Meteorological Institute Outline
(1) The increasing importance of the Arctic: changes under global warming, new economic activities, governance (2) Examples of potential users/usage areas for Arctic regional reanalysis (3) Related projects and datasets. How can Arctic regional reanalysis add value to already existing or planned global reanalysis and other datasets (4) Thoughts and suggestions on requirements for design of Arctic reanalysis What do we mean with «the Arctic»?
Definitions differ – there is no universally agreed southern border: . The Arctic circle 66° 33ʹ N . From climatology: The July 10°C isotherm (roughly coincides with N border for forest)
Here: Will not adhere to a strict definition, but it could be natural for C3S to have an interest in 1. key earth system processes 2. a geographical domain corresponding to European economical/administrative interests Illustration: Igesund/NPI Arctic climate – rapid change is seen
Temperatures increasing more rapidly than the global average – the “Arctic Amplification”
Sea ice – last 20 years: . Approximately half the summer coverage . Satellite and other data indicate a reduction of the order of 50% in sea ice thickness Summer sea ice volume roughly reduced to ¼
Permafrost temperatures have increased in most regions since the early 1980s
Impacts on ecosystems, economic activities, climate feedbacks, … Climate change: The sea ice decline
Snow and ice data provided by the National Center for Environmental Prediction/NOAA, NSIDC, U. Bremen Climate change: The sea ice decline (Sept.)
Projected and hindcasted September sea ice extent (colors and shading) for IPPC climate models and observations (black line). The shading indicates the one standard deviation range in the hindcasts and projections.
Credit: J. Stroeve and A. Barrett, National Snow and Ice Data Center Governance of the Arctic
Some main elements: •National states •International agreements •International cooperation entities •Arctic Council •EU has just adapted a new policy for the Arctic
Climate monitoring is one input for Arctic governance Governance of the Arctic
International legal frameworks that applies to the Arctic:
•The UN Convention on the Law of the Sea (UNCLOS), which asserts jurisdictional rights of nations in the various maritime zones.
•The Arctic Council is an international, intergovernmental forum - ”the primary body for circumpolar regional cooperation”. (The EU is an ad hoc observer to Arctic Council proceedings, 3 Member States are members of the Arctic Council, Denmark, Finland and Sweden, while seven Member States are permanent observers); Governance of the Arctic
On more specialized areas:
• The Barents Euro Arctic Council (BEAC) is the forum for intergovernmental and interregional cooperation in the Barents Region. The European Commission is a full member. • The Northern Dimension is a joint policy between the EU, Russia, Norway and Iceland. It was initiated in 1999 and aims at providing a framework to promote dialogue and concrete cooperation in issues such as economy, culture, environment and transport. • Transatlantic Ocean Research Alliance (US-Canada-Europe), the Galway agreement on ocean research, includes the Arctic. • The OSPAR Convention aims to protect the marine environment and ecosystems from emerging threats linked to pollution, maritime activities, together with climate change and increased human presence. • The International Maritime Organisation (IMO), a specialised agency of the United Nations with responsibility for the safety and security of shipping and the prevention of maritime pollution by ships. All EU Member States are IMO Members. The European Commission has an observer status. 27 April 2016: An integrated European Union policy for the Arctic
Background: The European Parliament and the Council in 2014 asked the Commission and the High Representative to develop an integrated policy on Arctic matters, with a more coherent framework for EU action and funding programmes.
. A policy proposal that will guide the actions of the European Union in the Arctic region. 3 main policy objectives: . protecting and preserving the Arctic in cooperation with the people who live there . promoting sustainable use of resources . international cooperation. . 39 actions listed An integrated EU policy for the Arctic - some of the 39 actions:
• Maintain current funding levels for Arctic research under Horizon 2020 (on average 20 million per year). Around 40 million has already been earmarked for 2016 and 2017 for projects on observation, weather and climate change in the northern hemisphere and permafrost decrease. • Support the transnational access to research infrastructures in the Arctic and the open access to data resources. The EU’s Copernicus space programme is to support international research on climate change in the Arctic. • Enhance coordination between EU funding programmes relevant for the Arctic, identify key investment and research priorities as well as facilitate capacity building of stakeholders to maximise financial support for the region. AMAP
Arctic council has six Working Groups. One of them is Arctic Monitoring and Assessment Programme (AMAP).
Project under AMAP: AACA - “Adaptation Actions for a Changing Arctic” – series of reports Example – some key messages from the draft Barents area AACA assessment
• The Arctic will warm faster than the average global warming, and temperature projections suggest a winter-time increase of the order 3-10 ºC between 2015 and 2080 if the future follows the path of RCP4.5. The RCP8.5 scenario may push the warming up to 20 ºC. • A higher proportion of the precipitation is expected to fall as rain in the future, amplified by the sea-ice retreat and increasing the risk of rain-on- snow events • A number of natural hazards are connected to synoptic storms, such as rain- on-snow events, avalanches, and extreme wave heights, but the current projection do not provide robust indications of a change other than a poleward shift in the storm tracks • Polar lows are small and violent storms that represent a risk to activities in the Arctic, and projections for the future suggest less favourable environment for their occurrence
13 Example – some key messages from the draft Barents area AACA assessment (2)
• The snow cover extent has decreased most at high latitudes (60-70°N), and the decline of snow cover in Eurasia over 2007-2014 has accelerated compared to earlier periods • The duration of the snow season has decreased, and the melt onset date in spring has advanced about 1-2 weeks in the 1979-2012, and the duration of snow-cover in 2050 will be about 30-40 % less than in 2011 • Observations of the snow quality suggests an increase in very hard snow layers from 1961 to 2009, with harder snow in early winter, more moist snow during spring, and future warming may bring more rain-on-snow events • The permafrost is thawing because of the Arctic warming, and the projected warming and increases in snow thickness will result in near-surface permafrost degradation over large geographic area
14 Some potential use areas for reanalysis
• Economic sectors: natural resource exploitation, fisheries, tourism, transportation • Climate system process studies • Climate model validation • Climate change effect studies • Ecosystem change studies: permafrost degradation, increasing runoff, coastal erosion, reduced ice thickness • Arctic Populations/communities commonly distributed along or dependent on coastal waterways and river systems for access and subsistence • Input to governance and resource management • For instance Arctic Council and its “Arctic Monitoring and Assessment Programme” Managing the risks in economic activities: Reanalysis can contribute
. Icing from seaspray . Sea ice, icebergs . Significant wave height . Storms . Extremely low temperature . High wind and low temperature . Currents . Sea states . Darkness 24/7 . Environment The Northern sea route
Arcticportal.org Lloyds (2012): «Arctic Opening: Opportunity and Risk in the High North» (1) Some points from analysis of a leading international insurance company:
•“Rapid and disruptive change in the Arctic environment presents uneven prospects for investment and economic development. All across the Arctic, changes in climate will create new vulnerabilities for infrastructure and present new design challenges.
•The Arctic is likely to attract substantial investment over the coming decade, potentially reaching $100bn or more. However, given the high risk/potentially high reward nature of Arctic investment, this figure could be significantly higher or lower.
•Arctic conditions will remain challenging and often unpredictable. Many of the operational risks to Arctic economic development – particularly oil and gas developments, and shipping – amplify one another. At the same time, the resilience of the Arctic’s ecosystems to withstand risk events is weak, and political and corporate sensitivity to a disaster is high.”
18 Lloyds (2012): «Arctic Opening: Opportunity and Risk in the High North» (2)
•“The environmental consequences of disasters in the Arctic are likely to be worse than in other regions.
•The challenges of Arctic development demand coordinated responses where viable, common standards where possible, transparency and best practice across the north. These frameworks need to be in place to enable sustainable development and uphold the public interest.
•Companies operating in the Arctic require robust risk management frameworks and processes that adopt best practice and contain worst case scenarios, crisis response plans and full-scale exercises.”
19 Economic activities in the Arctic Credit: http://arkgis.org/ Icing (ice accretion) conditions 1958-2013.
Norwegian Meteorological Institute Gunnar Noer, VNN, MET Norway
Polar lows 2000-2013
Norwegian Meteorological Institute EWWA – Changes in winter warming events in the Nordic Arctic Region
Trend in number of mild and rainy days dec.-feb.
From Vikhamar-Schuler et al (2013): Snow model Norwegian Meteorological Institute assessment of grazing conditions for reindeer Existing Arctic reanalyses/hindcasts – atmos/ocean/ice (probably uncomplete list)
Producer/ Variables Area Period/ resolution Obs. Used in DA Model and DA method Dataset
DMI Atmosphere Pan- 1999-2004, hourly, Synoptic data 3DVAR with ERAI as BC and Arctic 15km background; HIRLAM
DMI Ocean-sea ice Pan- 1994-2013, hourly, SST, Sea ice Nudging, HYCOM-CICE (incl. Arctic 10km concentration tide)
NERSC Ocean-sea ice Pan- 1991-2014, daily, Currents, T/S profiles, EnKF, Hycom/TOPAZ+NERSC (Copernicus Arctic 12.5km SST, SIC, SLA ice model (no tide) Marine Service)
MET Norway Atmosphere Regional 1957-present, 10km Hindcast only ERA40 BC and background, hindcast “NORA HIRLAM 10” MET Norway Atmosphere Local/reg Not completed, Hindcast only HARMONIE/AROME hindcast ional 2.5km SMHI Ocean-sea ice- Pan- IPY (2005-2007), AMSU-A, SST, SIC, in-situ HIRLAM (4D-Var), HIROMB atmosphere Arctic 22km atm.&ocean (OI) USA/Ohio Univ.: Atmos-ocean- Pan- 2000-2012, 3hourly, Polar WRF (3D-Var) Arctic System ice Arctic 15 and 30 km Reanalysis
Norwegian Meteorological Institute US: The Arctic System Reanalysis (ASR)
Polar Meteorology Group, Ohio State Univ. (Dave Bromwich), funded by NSF and NASA
Polar WRF with 3D-Var: • 15- and 30-km (inner domain) horizontal resolution versions • Version 1: 30 km version is complete for 2000- 2012 • Version 2: 15 km version with some model updates: available soon
Bromwich et al, QJ, 2016 – comparison of version 1 with ERA interim: Higher resolution terrain and detailed land- surface description useful Some verification scores better, some worse than ERAI http://polarmet.osu.edu/ASR/ Improvements over ERAI in near-surface fields Improvements in depiction of mesoscale processes Hindcast partly covering Arctic: «NORA10»
. Hindcast produced at MET Norway, NWP model HIRLAM is used to downscale ERA- 40 data to 0.1° resolution over Norway and adjacent sea areas incl parts of Arctic . Originally covered the ERA-40 period,until 2002, has since been extended using ECMWF operational analyses (Reistad et al. 2011, Haakenstad et al. 2012.)
Below figure from Reistad et al, 2009: Wind fields benefit from more resolved orography Summary: Need for high-resolution Arctic reanalysis vs existing datasets
Existing datasets for the atmosphere: • Resolution down to 10-15 km • Limited time ranges • Limited satellite data usage
Possible added value from a new reanalysis: • An open European dataset • Higher horizontal resolution would add value by • Capability to describe important mesoscale convective phenomena in cold air outbreaks over ocean (extreme surface heat fluxes, polar lows) • Forcing from lower boundary (orography, sea ice, snow cover, …) Major challenges for Arctic atmospheric reanalyses • Good datasets and strategies for the lower boundary: • Sea-ice with varying extent, ice concentrations and properties that influence the surface heat and moisture fluxes. • Snow cover/properties, glaciers (Greenland) • Coupling with sea ice/ocean model could come later • Very stable boundary layers connected to strong surface cooling • Vigorous convection over open ocean when air masses arrive from the sea-ice or cold land (Major Cold Air Outbreaks) • Mesoscale phenomena in cold air outbreaks over ocean: Extreme surface heat fluxes, convective systems, polar lows • The observing system: Use of satellite data will be important Vigorous convection: Polar lows
Satellite image of the polar low situation 6 March 2013 Polar lows (An unusual polar low 8 January 2010: First time a polar low has been observed North of Spitsbergen. Possible with retreat of winter sea ice. Polar lows form only over open ocean.)
MET Norway forecasters saw a significant improvement in Polar Low NWP modeling capability when resolution went to 10-15 km and below. Convection resolving models an advantage.
Norwegian Meteorological Institute Some experience regarding Greenland (DMI, IMO)
Glaciers need to be accounted for: • No glacier surface type was defined in SURFEX caused large drift in NWP output • Remedies were needed to remove drift, and turned out to make HARMONIE is able to simulate melt area well
It is important to use correct and updated physiography data for NWP modelling & reanalysis • Work is done to update Greenland ice sheet extent as included in the EcoClimap-II data set • Data from Greenland Mapping Project used to replace GMTED2010 topography
Danmarks Meteorologiske Institut 28. april 2016 Side 31 Veðurstofa Íslands The Arctic observing system
Upper air conventional observations: Example radiosonde (left) and aircraft coverage (right) (13 Sep 2013)
Observing system relies on remote sensing in the Arctic: Good use of remote sensing data is important for reanalysis quality Measuring of model quality with sea-level pressure forecasts
We chose to use pressure forecasts at coastal stations: • strongly connected to capturing the main weather systems • not as strongly influenced by local conditions at the measurement stations as for instance wind and temperature would be • is thus more comparable between different observing stations as a measure of the general quality of the large-scale forecast fields
Of interest to know atmospheric pressure variability which needs to be described for reference
Left: Mean absolute day-to-day observed pressure differences in hPa Model accuracy decrases towards the North (1)
The figures shows the RMS errors in pressure (vs observations) for forecasts in the range from 18 to 42 hours
· Left: Operational ECMWF global model (~16 km resolution) · Right: Operational HIRLAM 12 km regional model 34 Norwegian Meteorological Institute The Arctic Atmospheric observing system
Relies heavily on satellite data
A preliminary gap analysis • gap in pressure observations over sea ice and ocean areas • almost no coverage of near-surface wind observations over sea ice • gaps in conventional upper air data is compensated by data from satellite sounding instruments • data from temperature sounding in the lower troposphere is difficult to exploit the signals have surface contributions which are generally not well modelled (sea ice surface)
Both wind and temperature information in the lower Arctic troposphere is missing in the remote ocean and ice areas (Schyberg and Randriamampianina, EU ACCESS project)
35 Some onging frameworks for enhancement and coordination of the Arctic observing system
SAON – Sustaining Arctic Observing Networks
EU Horizon 2020 calls under «Blue Growth» (under evaluation): · BG-9-2016: Integrated Arctic Observing System · BG-10-2016: Impact of Arctic changes on weather/climate of Northern Hemisphere
ESA Polaris program: «… development of the next generation of space infrastructure to support both scientific and operational information needs in the rapidly evolving Polar Regions»
As well as planned polar orbiters from ESA and EUMETSAT (for instance ADM-Aeolus)
… sets the scene for increased quality and usefulness of Arctic reanalysis
36 Operational regional NWP systems in the Arctic
Upper: «AROME Arctic» of MET Norway Lower: DMI/IMO joint project
Both are HARMONIE/AROME: • At 2.5 km horizontal resolution
«AROME Arctic» at MET Norway: • 3D-Var data assimilation, conventional obs + AMSU/MHS, IASI, ASCAT • Ongoing work on AMV implementation • Sea ice and SST from daily OSI SAF products. Ongoing work on updated sea ice module in SURFEX.
37 Requirements for Arctic reanalysis could include: • Convection resolving? • Not fully pan-Arctic, but cover some domains of interest for economic activities and change processes • Make good use of the main components of the Arctic observing system (satellite datasets needed) • Make good use of complementary data on surface properties relevant in the area, such as ocean and sea ice, snow, … • Length of time period: similar to approach for other regional reanalysis datasets Summary
Arctic reanalysis can contribute to • Provide important input to studies of climate change and earth system processes in the area • Managing risk in emerging economic activitis in the area • Provide knowledge input to governance towards sustainable development of the area
Some suggestions: • Needs a good strategy for providing a good description of the lower boundary forcing: Sea ice, ocean, snow, glaciers • (A fully coupled atm.-ocean-seaice reanalysis a task for the future) • Higher resolution than global reanalysis will help description of convective phenomena in Arctic climate, effects of small scale orography and surface forcing Thank you!
Backup slides follow
40 Norwegian Meteorological Institute Regional downscaling - HARMONIE Climate branch Cooperation MET Norway with SMHI (and KNMI)
Norwegian Meteorological Institute UERRA: Uncertainties in Ensembles of Regional ReAnalyses Objectives • To produces ensembles of European regional meteorological reanalyses of Essential Climate Variables for several decades • To estimate the associated uncertainties in the data sets • To provide more observations for reanalyses • To provide data services and user information
Pre-operational Copernicus Climate Change Services
Norwegian Meteorological Institute UERRA Provide data sets and uncertainty estimates, building from FP7 EURO4M and extends in several dimensions:
More models and analysis systems (also gridded obs)
Ensembles
Much longer time period – 50+ years or 30 for ensemble
Higher resolution than ever before
More digitised observations rescued and provided
Quality and uncertainty measures
Comprehensive web based data and visualisation service
User guidance on user oriented products
Norwegian Meteorological Institute 44 3-D model level fields u,v,T,q,clouds, 2D fields precipitation, surface p, T, RH, snow and more
Met Office SMHI/MF Uni Bonn DWD
Hybrid 4D-Var, HARMONIE LETKF and Ensemble of 4D-VARs 3D-VAR Ensemble Nudging
1 Control 12 km 1 Control 12 km 1 member 11 km 70 levels 40 levels 65 levels 10 (20) members 24 km 20 members 12 km 2 members physics (5 y) ensemble ensemble
deterministic ~1961-2015 ensemble ~1978 -2015 5 years ensemble ensemble ~5 years
Conventional obs, Conventional obs, Large scale constraint Conventional obs satellite data, precip? from ERA Radar, new in LETKF
boundary forcing from global ERA reanalyses (ERA-40, ERA-Interim,ERA -5, incl. Ensembles,Norwegian EDA) Meteorological Institute 2-D surface fields analyses driven by 3D reanalyses
SMHI MF/SMHI SMHI MF SURFEX MESAN MESCAN HYPE and TRIP
2D advanced 2D advanced Hydrological Surface flux model Statistical Statistical physical Hydrological physical Interpolation interpolation model model
Downscaled Downscaled ERA, EURO4M and MESCAN 3D HIRLAM model ALADIN model UERRA reanalyses atmospheric Climatological background Precipitation and variables and adaptation background temperature forcing precipitation Surface and climate AVHRR, METEOSAT stations No input observations SEVIRI and No input observations T, Td, Validation against MVIRI Validation against precipitation discharge data discharge data
5 km Europe 5 km Europe River discharge River discharge T2m, RH, 24 h Cloud fraction 35000 catchments 25 km -> rivers precipitation hourly Europe, median 215 km2
1961 - ~2013 ~1982 - 2013 ~1979 - 2010 ~1981 - 2010 Norwegian Meteorological Institute Uncertainty estimations
Evaluate ensemble reanalyses and downscaled reanalyses through comparison to independent ECV datasets that were derived independently
Establish a consistent knowledge base on the uncertainty of reanalyses across all of Europe through a common evaluation procedure o Extremes, Climate Indices and Indicators of user interest, scales of variablity
Statistically assess the provided information by applying the common evaluation procedure on all data
User dependent parameters and language adaptation
Norwegian Meteorological Institute Sea Ice Concentration Climate Data Record
1979 (sept) 2015
2012
1979
1978 - 2015 : Climate Data Record 2015 - … : Interim CDR SIC Algorithm, Processing, and Operationality
Some unique features of the algorithm:
Dynamic adjustments of the algorithm tie-points (=> Consistency) ;
Maps of uncertainties;
Rooted in the OSISAF, consolidated by the ESA CCI Sea Ice R&D.
Processing chain:
Engineered in the OSISAF, consolidated by ESA CCI Sea Ice.
Scalable data re-processing system at MET Norway (but data volumes are small).
Operational in the sense of EUMETSAT SAF and CMEMS:
Review cycles (Req. Review, Product Consolidation Review, Delivery Readiness Review);
Traceability of requirements, CORE-Climax Maturity Matrix, CEOS ECV Inventory,... Sea Ice Type, Sea Ice Drift, ...
March 2015
M. Tschudi (2014) US NSIDC
S. Kern (2016) June snow cover 2012 relative to 1971-2000
Credit: James Overland