CORDEXCORDEX

A Coordinated Regional Downscaling A Coordinated Regional Downscaling ExperimentExperiment

Colin Jones & Filippo GiorgiColin Jones & Filippo Giorgi

Task Force : Ghassem Asrar, Jens Christensen,Greg Flato, Clare Gooddess, Bill Gutowski, Bruce Hewitson, Richard Jones, Won-Tao Kwan, Krishna Kumar,

Claudio Menendez, James Murphy, Serge Planton

Some (sparse) details at: http://wcrp.ipsl.jussieu.fr/SF_RCMTerms.html

General Aims and Plans for CORDEXGeneral Aims and Plans for CORDEX

Provide a set of Regional Climate Scenarios Provide a set of Regional Climate Scenarios covering the period 1950-2100, for the majority covering the period 1950-2100, for the majority of the populated land-regions of the globe.of the populated land-regions of the globe.

Make these data sets readily available and Make these data sets readily available and useable to the impact and adaptation useable to the impact and adaptation communities.communities.

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

Foster coordination between Regional Foster coordination between Regional Downscaling efforts around the world and Downscaling efforts around the world and encourage participation inencourage participation inthe downscaling process of local the downscaling process of local scientists/organizationsscientists/organizations

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

Sources of uncertainty in RCD-based Sources of uncertainty in RCD-based

Regional climate projectionsRegional climate projections

More specific aims and plans for CORDEXMore specific aims and plans for CORDEX(resulting from a discussion meeting in Toulouse Feb 2009)(resulting from a discussion meeting in Toulouse Feb 2009)

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. More than 1 representative greenhouse emission 4. More than 1 representative greenhouse emission scenarioscenario

5. With common RCM domains and resolution5. With common RCM domains and resolution

6. With common RCM output variables and frequency6. With common RCM output variables and frequency

7. In a common format7. In a common format

8. Store the results online for subsequent access and 8. Store the results online for subsequent access and useuse

What has been decided/suggested (results from the Toulouse Feb 2009 meeting)

1.1.A request to GCM groups to archive 6-hourly 3D modelA request to GCM groups to archive 6-hourly 3D modellevel fields was included in the CMIP5 output protocol.level fields was included in the CMIP5 output protocol.

The request was for at least 1 member of an RCP4.5 The request was for at least 1 member of an RCP4.5 integration and if possible an RCP8.5 run also.integration and if possible an RCP8.5 run also.

It is not yet clear how many GCM groups will provideIt is not yet clear how many GCM groups will providethis data but at least 5-6 GCMs seems quite likely.this data but at least 5-6 GCMs seems quite likely.

2.2.The standard RCM resolution is 50km The standard RCM resolution is 50km (groups are (groups are encouraged to test higher resolutions, but please do the standard)encouraged to test higher resolutions, but please do the standard)

3.Groups are encouraged to run as many of the 3.Groups are encouraged to run as many of the RCMRCM domains as possible using the ERA-interim data domains as possible using the ERA-interim data asas boundary conditions (1989-2008) for model boundary conditions (1989-2008) for model evaluationevaluation

4.An initial focus for future climate scenarios will 4.An initial focus for future climate scenarios will be be Africa Africa with an aim to provide something for with an aim to provide something for IPCC AR5IPCC AR5

5.Emission scenarios: 5.Emission scenarios: (a) RCP4.5 (b) RCP8.5 (c) (a) RCP4.5 (b) RCP8.5 (c) RCP2.5RCP2.5

6.Either full transient runs 6.Either full transient runs 1950-21001950-2100 or time or time slicesslices for in order of preferencefor in order of preference::

(a) 1980-2010(a) 1980-2010 (b) 2040-2070(b) 2040-2070 (c) 2010-2040(c) 2010-2040 (d) 2070-2100 (d) 2070-2100 (e) 1950-1980(e) 1950-1980

Issues not yet fully resolvedIssues not yet fully resolved

1.1.Standard output data set (variables, frequency etc)Standard output data set (variables, frequency etc)

2.2.Format of output (most likely follow CMIP5 protocol)Format of output (most likely follow CMIP5 protocol)

3.3.Location of ‘online’ RCM storage + mechanism forLocation of ‘online’ RCM storage + mechanism fordata access/distribution.data access/distribution.

CORDEX domainsCORDEX domains

NARCCAPNARCCAP

CLARISCLARIS

ENSEMBLESENSEMBLES

RCMIPRCMIP

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

1951-21001951-21001981-2010, 2041-2070, 2011-20401981-2010, 2041-2070, 2011-2040

Multiple regions (Initial focus on Africa)Multiple regions (Initial focus on Africa)50 km grid spacing50 km grid spacing

Regional AnalysisRegional AnalysisRegional DatabanksRegional Databanks

Some ConclusionsSome Conclusions

The RCD community is beginning to get organizedThe RCD community is beginning to get organized

Regional Models can provide useful information on topRegional Models can provide useful information on topof GCM dataof GCM data

A coordinated, ensemble approach seems beneficialA coordinated, ensemble approach seems beneficial

Hopefully we will succeed in getting a range of RCM Hopefully we will succeed in getting a range of RCM scenarios Driven by a number of GCMs and emission scenarios Driven by a number of GCMs and emission scenarios for a number of domains around the world.scenarios for a number of domains around the world.

Important to make this data available to a wide audienceImportant to make this data available to a wide audience