International efforts in Climate Modeling Projections, Predictions and Downscaling

Coordinated by the World Climate Research Program (WCRP)

CMIP5: The 5th Coupled Model Intercomparison Project

http://cmip-pcmdi.llnl.gov

CORDEX: A Coordinated Regional Downscaling Experiment

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

Colin JonesRossby Centre, SMHI

Thanks to: Karl Taylor (PCMDI), Filippo Giorgi (ICTP), Ghassam Asrar (WCRP)

Promotes a standard set of model simulations in order to : evaluate how realistic the models are in simulating the recent past provide projections of future climate change on two time scales understand factors responsible for model differences

Two timescales and two sets of science problems

An important input to IPCC AR5

Taylor et al. 2009, http://cmip-pcmdi.llnl.gov/cmip5/

Near-Term :(next 1-30 years)

decadal climate predictability

ocean initialization

aerosol impacts

regional climate change (high resol) & climate extremes

air quality changes (aerosols, chemistry)Long-Term :(1860 to 2100 & beyond)

evaluation of climate models(e.g. new satellite data)

detection & attribution

climate change scenarios

climate sensitivity, radiativeforcing and physical feedbacks (e.g. clouds)

biogeochemical feedbacks(e.g. carbon, chemistry)

CMIP5 : a framework for climate change modeling for the next 5+ years

CMIP5: Centennial Timescales: Earth System Modeling

Aims to improve our ability to simulate all processes that influence the response of the climate system to increasing greenhouse gases

Cloud Feedbacks

Carbon-Climate Feedback (Ocean and Terrestrial)

Aerosol Feedbacks

Sea-Ice/Snow Feedbacks

Ocean circulation changes

Ice Sheets/Glacier response

Sea-level changes

Ocean acidification and ecosystem response

Permafrost and Methane Release

To better constrain the lower and upper bounds of anthropogenic climate change requires (an accurate and complete) representationof complex and interacting process in Earth System Models

Start from a pre-industrial spin-up run (>500 yrs)The 20th century control run includes observed changes in GHG, aerosol concentrations, volcanoes, and land-use from 1850-20053 RCP scenarios for the 21th century Possibly extend with more RCP scenarios, 1% CO2 increase, CMIP5: centennial projections20th century control185019001950200020502100RCP8.5RCP4.5Spin-upRCP2.6

First CMIP5 projections results now becoming available

Decadal predictability and climate predictionPredictability we are familiar with arises from an estimateof future changes in GHG radiative forcing, and the climate system response to those changes.

Predictability might also arise from information contained in the initial state of the system

- committed warming due to previous GHG forcing- natural variability of the systemTom Delworth GFDLAssuming we can (i) observe this information (ii) assimilate it in our models, (iii) the variability has a predictable componentand (iv) our models are good enough to simulate the subsequent evolution of the climate system

We may be able to provide useful information about the evolution of the climate system on a ~1-20 year timescale.

Climate Prediction as a mixed initial/boundary value problem

The Atlantic Meridional Oscillation indexA 10-yr moving average of annual North Atlantic SST anomalies Linked to variability in the Atlantic Meridional Overturning Circulationcrucial to simulate the time evolution of AMOC for decadal prediction

There appears to be some increased skill (in a quantitative sense)when observations are included in coupled climate model predictions

Results from the UK Met. Office DePreSys integrationsD. Smith etal. UKMO

CMIP5: decadal prediction experiments196019701980199020002010202010 yrs10 yrs10 yrs10 yrs10 yrs10 yrs10 yrs10 yrs10 yrs10 yrs10 yrs+20 yrs+20 yrs+20 yrsStart a 10-yr experiment every 5 yearsInitialize from observation-based re-analysis of atmosphere and oceanExtend a few runs to 30 yrsDecadal prediction still a researchtopic: Targeted for ~1-20 yearTimescale : climate services ?

Hindcast simulations to assess skill & uncertaintyTest ocean and sea-ice initialisation techniquesInterpretation of results not easy (potential predictability)

It may be that much of the predictive skill for the comingdecade (and beyond) will result from the forced GHG response not the initialized climate state.

Results from initialized climate simulations often require(bias/drift) corrections: Application of these corrections is not trivial, there is danger of incorrect interpretation.

For non-experts it may be safer & perhaps as informative touse output of the first few decades of the long-term CMIP5experiments (uncertainty issues will need to be addressed)

In both cases an ensemble approach is an absolute necessity

Decadal climate prediction is still in an exploratory stage

CMIP5 output will be made available to everyoneTerms of use:

All output available for educational and research use

About half of all output available for unrestricted use.

Extensive documentation will be available describing the models and the experiment conditions.

Model data accessed via a federated Earth System Grid led by PCMDI connecting identical accessible/structured distributed archives across the world.

Actual location of model data invisible to the user

Data Providers (modeling groups)Users (climate model analysts)Data ArchiveESG Gateway (PCMDI)Copy of heavily-used output

Model & expt. documentationDOI catalogHow will users access CMIP5 model output? ESG

CORDEX

A Coordinated Regional Downscaling Experiment

Sponsored by the World Climate Research Programme 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, based on a suitable sample of CMIP5 GCM projections.

Strong orientation towards user needs: impacts and adaptation

General Aims and Plans for CORDEXProvide an ensemble of coordinated Regional Climate projections for 1950-2100 (core 1980-2050), for most land-regions of the globe based on CMIP5 simulations following RCPs 4.5, 8.5 and 2.6

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

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

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

With CMIP5 provide climate simulation data to support IPCC AR5 and impact-adaptation-vulnerability research on longer timescales

International emphasis on African climate & impacts coming 2 years: START/WCRP analysis, training & capacity building activity 2011-12

Uncertainty inregional climateprojectionEmission/ConcentrationScenariosAOGCM Configuration(Multiple AOGCMs)Internal variability(Multiple realizations)RCD Configuration(Multiple models)RCD approach(Multiple RCD methods)Region Sampling the sources of uncertainty in RCD-based Regional climate projections

CORDEX Phase I experiment design Model Evaluation FrameworkClimate ProjectionFrameworkERA-Interim BC 1989-2008Multiple AOGCMsRCP4.5, RCP8.5some RCP 2.6 runsRegional Projections 1950-2100Multiple regions (Initial focus on Africa)50km resolution (higher in some regions, Europe: 10km)Regional AnalysisRegional DatabanksEurope, Korea, S.Africa

CORDEX DOMAINS (plus Arctic & Antarctica)12 domains with a resolution of 0.44 (approx. 50x50km)Focus on Africa : 11 groups committed to run Africa projectionsHigh resolution ~0.11x0.11 for Europe (~6 institutions)

What has been decided in CORDEX

6-hourly 3D model level fields will be saved by CMIP5 GCMs making climate projections as boundary forcing for RCMs At least 1 RCP4.5 and 1 RCP8.5 member (1950-2100) per GCM. Many GCMs will also save an RCP2.6, plus > 1 RCP4.5 member

This data will become available on the CMIP5 data nodes in May to October 2011The standard resolution is 50km (many groups plan to also run higher resolution for selected domains, e.g. ~10km Europe ensemble) 50km base resolution to include as many groups as possible

3.Before GCM forced runs for a given region RCMs must be run with ERA-interim (1989-2008) for the same region 4.An initial (international) focus for climate projections will be Africa with an aim to provide input to the IPCC AR5 process

Seasonal Mean Precipitation JAS 1998-2008

Seasonal Mean Precipitation Bias: Land GPCC

Annual Cycle spatially averaged precipitation

Annual Cycle spatially averaged precipitation

Annual Cycle spatially averaged precipitation

Annual Cycle of West African Monsoon5-day mean rainfall averaged between 10W to 10E

Health impact examples: Malaria Incidence over Africa: 2000-2008Mean annual malaria Incidence (%) based on the Liverpool Malaria Model (LMM) for the period 2000-2008.

The LMM has been driven by different observations (NCEP, ERAINTERIM and a hybrid run using GPCP rainfall and ERAINT temperatures) and one RCM from the CORDEX project (SMHI-RCA35, ERAINT control exp).

The RCM fairly well reproduces the mean annual distribution of malaria incidence with respect to the GPCP-ERAINT run.. A.MorseU. Liverpool

Health impact examples: Malaria Prevalence over Africa: 2000-2008Mean annual malaria Prevalence (%) based on the Liverpool Malaria Model (LMM) for 2000-2008.

The LMM has been driven by different observations (NCEP, ERAINTERIM and a hybrid run using GPCP rainfall and ERAINT temperatures) and one RCM from the CORDEX project (SMHI-RCA35, ERAINT control exp).

The RCM reproduces well the mean annual distribution of malaria prevalence with respect to the GPCP-ERAINT run (best estimate).. A.MorseU. Liverpool

Annual Cycle of Central African Rainfall Monthly mean rainfall averaged between 10E to 25E

Summary

CMIP5 & CORDEX will deliver an unprecedented set of coordinated Global and Regional climate simulations over the coming ~1-4 years

These data cover both the historical past, near-term predictions and a range of GHG/land-use scenario forced future projections

CORDEX data will provide 50km (higher in some regions) ensemblesof downscaled regional climate projections for most land regions ofthe world for use in impact-adaptation-vulnerability research

CORDEX has developed regionally-specific, locally-led evaluation and analysis teams, with coupled capacity building and training activitiese.g. Africa CORDEX WCRP/START training and analysis workshops.

Both CMIP5 and CORDEX can provide important input to the evolving Climate Service sector for regions worldwide

*Policy makers, engineers, planners need to make decisions which have to take into account climate change which is uncertain. Include uncertainty in cost benefit analysis of long-term plan e.g. new Thames barrier.

Thames Barrier was designed to cope with tidal levels that were anticipated by 2030. A new Thames Barrier is being planned and this one will have to last into next century. Theyll need to know about uncertainty in predicted climate change to assess the risks and make a good decision.

What is the measure of uncertainty?

**Mention BER vision**