CORDEXCORDEX

A Coordinated Regional Downscaling A Coordinated Regional Downscaling ExperimentExperiment Sponsored by the World Climate Research Sponsored by the World Climate Research ProgrammeProgramme

Colin Jones & Filippo GiorgiColin Jones & Filippo Giorgi Thanks to Grigory Nikulin (SMHI), Daniela Jacob & Paolo RutiThanks to Grigory Nikulin (SMHI), Daniela Jacob & Paolo Ruti

http://wcrp.ipsl.jussieu.fr/SF_RCMTerms.html

Generating an ensemble of high-resolution regional climate projections for the majority of land regions of the globe, consistent with a suitable sample of CMIP5 GCM projections.

Higher resolution often results in improved precipitation

UKMet: HadCM3

Daily rainfall intensity over the Alps

(HC models)

Higher resolution can provide an improved simulation of extremes

UKMet: HadCM3

Different GCMs can give different regional climate change signals

Winter season temperature change (2016-2045)–(1961-1990)

Greater relative differences between simulated climate change signal.

Even between 3 members of the same GCM with same emission scenario(ECHAM5 A1B) but different initial conditions.

Circulation plays a 1st order role in determining regional climatevariability and still will in the years of anthropogenic climate change

Seasonal Mean temperature averaged over Southern Sweden (500km2) from 3 RCA3 ensemble members all driven by ECHAM A1B scenarios

General Aims and Plans for CORDEXGeneral Aims and Plans for CORDEX

Provide an ensemble of coordinated Regional Climate Provide an ensemble of coordinated Regional Climate Scenarios for 1950-2100, for the majority of land-regions of Scenarios for 1950-2100, for the majority of land-regions of the globethe globe

Make this data available and useable to users, with a Make this data available and useable to users, with a common diagnostic set and format (following CMIP5) at common diagnostic set and format (following CMIP5) at archivesarchives

Provide a framework for testing Regional Climate Models Provide a framework for testing Regional Climate Models and Downscaling techniques for the recent past and future and Downscaling techniques for the recent past and future scenarios.scenarios.

Foster coordination between downscaling efforts around Foster coordination between downscaling efforts around the world & encourage local participation in this process the world & encourage local participation in this process esp .developing nationsesp .developing nations

With CMIP5 provide climate simulation data to support With CMIP5 provide climate simulation data to support IPCC AR5.IPCC AR5.

More specific aims and plans for CORDEXMore specific aims and plans for CORDEX

Develop a matrix of RCD simulations that Develop a matrix of RCD simulations that employ:employ:

1.1. Multiple GCMs as boundary conditions (BCs)Multiple GCMs as boundary conditions (BCs)

2. Multiple realizations of a given (single) GCM as BCs2. Multiple realizations of a given (single) GCM as BCs

3. Multiple RCMs driven by a given GCM over a given 3. Multiple RCMs driven by a given GCM over a given domaindomain

4. Multiple ESD approaches for a given GCM and 4. Multiple ESD approaches for a given GCM and domaindomain

5. More than 1 representative greenhouse emission 5. More than 1 representative greenhouse emission scenarioscenario

6. With common RCM/ESD domains and resolution6. With common RCM/ESD domains and resolution

7. With common output variables and frequency7. With common output variables and frequency

8. In a common format closely following CMIP58. In a common format closely following CMIP5

9. Results freely available for subsequent access and 9. Results freely available for subsequent access and useuse

Uncertainty inUncertainty inregional climateregional climate

projectionprojection

Emission/Emission/ConcentrationConcentration

ScenariosScenarios

AOGCM ConfigurationAOGCM Configuration(Multiple AOGCMs)(Multiple AOGCMs)

Internal variabilityInternal variability(Multiple realizations)(Multiple realizations)

RCD ConfigurationRCD Configuration(Multiple models)(Multiple models)

RCD approachRCD approach(Multiple RCD methods)(Multiple RCD methods)

RegionRegion

Sampling the sources of uncertainty in Sampling the sources of uncertainty in

RCD-based Regional climate projectionsRCD-based Regional climate projections

What has been decidedWhat has been decided

1.1. Selected 6-hourly 3D model level fields as output Selected 6-hourly 3D model level fields as output included in the CMIP5 GCM output protocol.included in the CMIP5 GCM output protocol. AAt least 1 RCP4.5 and 1 RCP8.5 member (1950-2100).t least 1 RCP4.5 and 1 RCP8.5 member (1950-2100).

Also at least 3 ensemble members from decadal Also at least 3 ensemble members from decadal prediction prediction (2005-2035) and hindcast runs (1985-2005, 1990-2000).(2005-2035) and hindcast runs (1985-2005, 1990-2000).

2.2. The standard RCM resolution is 50kmThe standard RCM resolution is 50km ((many groups many groups plan to plan to

also run higher resolutions for selected domains, e.g. ~10km also run higher resolutions for selected domains, e.g. ~10km EuropeEurope).).

50km base resolution to include as many groups as 50km base resolution to include as many groups as possiblepossible

3.Before making GCM forced runs for a given region 3.Before making GCM forced runs for a given region groupsgroups should run the RCM forced by ERA-interim (1989-should run the RCM forced by ERA-interim (1989-2008) 2008) over that region for model evaluation.over that region for model evaluation.

4.An initial (international) focus for future climate 4.An initial (international) focus for future climate scenarios scenarios will be will be AfricaAfrica with an aim to support the IPCC AR5 with an aim to support the IPCC AR5 processprocess

CORDEX Phase I experiment design CORDEX Phase I experiment design

Model Evaluation Model Evaluation FrameworkFramework

Climate ProjectionClimate ProjectionFrameworkFramework

ERA-Interim BC ERA-Interim BC 1989-20071989-2007

Multiple AOGCMsMultiple AOGCMs

RCP4.5, RCP8.5RCP4.5, RCP8.5

1951-21001951-2100Decadal hindcasts & predictionsDecadal hindcasts & predictions

Multiple regions (Initial focus on Africa)Multiple regions (Initial focus on Africa)50km resolution (higher in some regions, Europe: 10km)50km resolution (higher in some regions, Europe: 10km)

Regional AnalysisRegional AnalysisRegional DatabanksRegional Databanks

CORDEX DOMAINS (except Arctic & Antarctica)

•12 domains with a resolution of 0.44° (approx. 50x50km²)•Focus on Africa•High resolution ~0.11°x0.11° for Europe (by some institutions)

Annual mean precipitation [mm/month], 1989-2006

CRU TS3.0 (Mitchell and Jones, 2005)

CRU 3.0 REMO

Evaluation of Annual Mean Precipitation

Annual mean difference of temperature [K]: REMO-CRU,

1989-2006

• Positive bias in areas of upwelling ocean currents

Evaluation of Annual Mean Temperature

16

Med-CORDEX (linked to HYMEX)Med-CORDEX (linked to HYMEX)

Groups involved in Med-CORDEXGroups involved in Med-CORDEX

** Includes a coupled Mediterranean** Includes a coupled Mediterranean

- LMD- LMD (WRF) **(WRF) **- ICTP-ENEAICTP-ENEA (RegCM+MIT) **(RegCM+MIT) **- CNRMCNRM (ALADIN) **(ALADIN) **- MPIMPI (REMO) **(REMO) **- UCLM UCLM (PROMES)(PROMES)- WRF community WRF community … SMHI, COSMOS… SMHI, COSMOS

ARCHIVE:List of the CORE runs (STAND ALONE + COUPLED):List of the CORE runs (STAND ALONE + COUPLED):50 km RCM (25 Km)50 km RCM (25 Km)1989-2008, ERAInterim driven1989-2008, ERAInterim driven1950-2100, Scenarios RCP4.5 and/or RCP8.5, AR5-GCM driven1950-2100, Scenarios RCP4.5 and/or RCP8.5, AR5-GCM driven

Empirical-Statistical Downscaling in CORDEXEmpirical-Statistical Downscaling in CORDEX

CORDEX-ESD group forming: CERFACS, Univ Cape CORDEX-ESD group forming: CERFACS, Univ Cape Town, Met.No, Santander, Queensland (so far)Town, Met.No, Santander, Queensland (so far)

Over Africa: Aim to compare ESD and RCM Over Africa: Aim to compare ESD and RCM downscaleddownscaledClimates from common GCM forcings & gridsClimates from common GCM forcings & grids Proposal to make a controlled comparison Proposal to make a controlled comparison between various ESD Methods and with RCM between various ESD Methods and with RCM downscaling of ERA-interim and CMIP5 Control downscaling of ERA-interim and CMIP5 Control Climate simulationsClimate simulations

Use RCMs to investigate the ESD-assumed Use RCMs to investigate the ESD-assumed relationshiprelationshipbetween large-scales and small(er) scalesbetween large-scales and small(er) scales

Initially for: Africa, Europe, and Euro-Initially for: Africa, Europe, and Euro-MediterraneanMediterranean

Need for an active CORDEX-ESD group (?) and Need for an active CORDEX-ESD group (?) and more presence of ESD expertise on the WCRP more presence of ESD expertise on the WCRP Task Force.Task Force.

Initial Results from 5 RCMs run for 1989-2008 at 50km forced by ERA-interim boundary conditions

CORDEX review article summer 2010

RCMs that have/are made theAfrica ERA run and willwill makescenario runs for Africa

UCT/UK Met. : PRECISSantander/Bergen/LMD : WRFU Murcia : MM5ICTP : RegCM3UQAM : GEM_LAMOuranos : CRCM4CCCma : CanRCMMeteo France : ARPEGEKNMI : RACMOJRC : CLMMPI : REMODMI : HIRHAMSMHI : RCA

Uncertainty inUncertainty inregional climateregional climate

projectionprojection

Emission/Emission/ConcentrationConcentration

ScenariosScenarios

AOGCM ConfigurationAOGCM Configuration(Multiple AOGCMs)(Multiple AOGCMs)

Internal variabilityInternal variability(Multiple realizations)(Multiple realizations)

RCD ConfigurationRCD Configuration(Multiple models)(Multiple models)

RCD approachRCD approach(Multiple RCD methods)(Multiple RCD methods)

RegionRegion

Sampling the sources of uncertainty in Sampling the sources of uncertainty in

RCD-based Regional climate projectionsRCD-based Regional climate projections

JAS seasonal mean precipitation 1998-2008

Northern west Africa region

Southern west Africa region

2-6 day band passed precipitation Standard deviation (StDEV) (JAS)

Highlights AfricanEasterly wavesi.e.Transientsi.e.Transients

2-6 day StDEV of meridional wind at 850hpa (JAS)

ERA-interim underestimates AEW StDEV in precipitation comparedERA-interim underestimates AEW StDEV in precipitation comparedto TRMM which suggests that the StDEV in v850 may also be an to TRMM which suggests that the StDEV in v850 may also be an underestimate in ERA-interimunderestimate in ERA-interim (e.g. RCMs are likely more realistic)(e.g. RCMs are likely more realistic)

EC-Earth ~1.25° run with prescribed SSTs exhibits the same underestimate of StDEV for precipitation

ECEARTH 2.1 has IFS physics almost identical to used in ERA-interim

2-6 day band passed precipitation Standard deviation (StDEV) (JAS) TRMM data averaged to 1.25° and RCA with increasing resolution

Consistent with reduced precipitation StDev compared to ERA-interim meridional wind StDEV at 850hpa is also reduced in EC-Earth

Wind variance is much less sensitive to resolution than precipitationOK. Diabatic heating affects dynamics on a larger spatial scale.

JAS mean diurnal cyclemean diurnal cycle of precipitation (1998-2008) Northern West Africa region

Time of precipitation maximum within the diurnal cycle JAS 1998-2008

Summary

CORDEX has now started

Africa-CORDEX becoming organized, 13 groups making ERA-interim runs 1989-2008 on a common Grid, 50km grid. An Africa diagnostic & evaluation panel has been formed led by Univ of Cape Town.

Euro-CORDEX & Med-CORDEX domains are also organizing. ERA-interim runs at 10km resolution in progress. MPI leads the formation of a European diagnostic/evaluation panel

South America CORDEX becoming organized (based around CLARIS)

CORDEX ESD group also now forming.

1st CMIP5 boundary data available late 2010. Discussions occurring how best to distribute these along with planning the best approach to filling the multi-dimensional GCM/RCM/ESD/emission matrix

An initial CORDEX archive will be available in August at DMI.Discussion with CMIP5 archive centres begun regarding use of ESG