Warren M. Washington Warren M. Washington NCARNCAR

The Parallel Climate Model (PCM) The Parallel Climate Model (PCM) and Transition to a Climate and Transition to a Climate

Change Version of the Change Version of the Community Climate System Community Climate System

Model (CCSM)Model (CCSM)

Climate Change SimulationsClimate Change Simulations

Present and future climate change and assessment simulations

Merged CSM and PCM model

Future research needs

Present and Future cooperation between NSF and DOE

Partial List of Distributed InvolvementPartial List of Distributed InvolvementDOE and NSF Supported Project withDOE and NSF Supported Project with::

Los Alamos National LaboratoryLos Alamos National Laboratory National Center for Atmospheric ResearchNational Center for Atmospheric Research Naval Postgraduate SchoolNaval Postgraduate School Oak Ridge National LaboratoryOak Ridge National Laboratory University of Texas, AustinUniversity of Texas, Austin Scripps Oceanographic InstituteScripps Oceanographic Institute DOE Program on Climate Diagnostics and IntercomparisonDOE Program on Climate Diagnostics and Intercomparison U.S. Army Cold Regions Research and Engineering LaboratoryU.S. Army Cold Regions Research and Engineering Laboratory National Energy Research Supercomputer CenterNational Energy Research Supercomputer Center Lawrence Berkeley National LaboratoryLawrence Berkeley National Laboratory OthersOthers

Contributions to the DOE Climate Contributions to the DOE Climate Change Prediction Program (CCPP)Change Prediction Program (CCPP)

Develop climate modeling capability that takes advantage of new generation parallel architecture supercomputers

Build on the previous DOE CHAMMP modeling developments

Develop model components and coupled models that can be used for energy policy, IPCC, and future National Assessments

HistoryHistoryCSM1 and PCM1 CSM1 and PCM1

Built for vector/parallel Computers system

Atmosphere: CCM3 Ocean component:

NCAR ocean model Sea ice dynamics of

Flato-Hibler dynamics and simplified thermodynamics

Built for distributed parallel Computer system

Atmosphere: CCM3 Ocean component: LANL

Parallel Ocean Program (POP)

Sea ice Model -Naval Postgraduate School model: viscous plastic dynamics; simplified thermodynamics

Coupler Overview• Enables coupled model to be

constructed from independent components

• Controls execution of component models

• Computes interfacial fluxes

• Implements conservative mapping of fluxes of momentum, energy, and water between different grids

CouplerLand Ice

Atmos

Ocean

Coupler: Design Goals• Support both sequential & distributed execution

• High-performance scalable parallel implementation of performance-sensitive regridding and communication operations

– Address parallelism and load balance issues

• Run-time rather than compile-time specification of processor allocations

• Support for stand alone execution

Merging of CSM and PCM

Agreement to use the same model components

CSM, PCM, and DOE lab staff will develop a merged flux coupler b– ongoing SciDAC team of NCAR and DOE laboratory involvement

Full merger occurs when the CCSM is available for climate change simulations and the new flux coupler

NSF and DOE efforts may use different resolutions with DOE emphasis on high resolution studies for regional climate change studies

Computational Design Question

Parallel Integration

Sequential Integration (stacked)

ATMOSPHEREATMOSPHERE

COUPLERCOUPLER

ATMOSPHEREATMOSPHERE

OCEANOCEAN

SEA ICESEA ICE

RIVER RIVER TRANSPORTTRANSPORT

LAND/LAND/VEGETATIONVEGETATION

RIVER RIVER TRANSPORTTRANSPORT COUPLERCOUPLER LAND/LAND/

VEGETATIONVEGETATIONSEA ICESEA ICEOCEANOCEAN

TIME

TIME

Coupled System Processor Layout

PCM

CCSM2

Target?

CSM1

10/24/2001

0

50

100

150

200

250

1995 1996 1997 1998 1999 2000 2001

Simulated Years per Wallclock Month

64pes

PCM Version 1 - NERSC Machines

T3D

T3E-600

T3E-900

IBM SP

WHI

IBM SP WHII

Sim

ula

ted

Years

Year

IBM SP NHII

David Pierce Scripps Institution of Oceanography

Examples of Climate Change Experiments

Greenhouse gases

Sulfate aerosols (direct effect)

Stratospheric ozone

Land surface changes

Volcanic forcing

Solar change forcing

Carbon soot aerosol (Indian-Asian region)

Various energy/emissions use strategies

PCM Historical and Future Simulations

Use of CSM greenhouse gas and sulfate aerosol forcing

1870 control simulation

Historical 1870 to present

IPCC “Business as Usual” assumption

IPCC stabilization assumption

Ensemble of 10 for Historical, BAU/STAB ensemble 5

Solar variability simulation-ensemble of 4

Simulations to year 2200-ensemble BAU/STAB 3

Both prominent in the IPCC Third Assessment Report (2001)

Both represented in the IPCC Data Distribution Centre (Hamburg)

Both represented in the CLIVAR Coupled Model Intercomparison Project (CMIP): CMIP1, CMIP2, CMIP2+

Access to CSM: via NCAR (CSM web page)

Access to PCM: runs archived at PCMDI (contact Mike Wehner: mwehner@pcmdi.gov)

PCM and CSM Presence in the International PCM and CSM Presence in the International Climate Modeling CommunityClimate Modeling Community

Interim Model: “PCM-CSM Transitional Model” (PCTM)

POP with GM and KPP (LANL, NCAR, NPS), R. Smith grid modifications (LANL)

C. Bitz sea ice multi-thickness(5) distribution thermodynamics and E. Hunke et al. elastic viscous plastic dynamics (U. of Washington, LANL, NCAR)

River Transport, Branstetter and Famiglietti (U. Of Texas, Austin, NCAR)

Future Developments and Simulations

More simulations with Black Carbon distributions in PCM1 over entire globe

Higher resolution atmosphere -T85d simulations

Improved archival and cataloging of large data sets - EARTHGRID/DOE/

Simulations related to DOE mission on energy use impacts on the climate system - ACPI demonstration project

Work with statistical community on signal to noise

CCSM2 climate change simulations early next year

Why T85?Why T85?

Improved regional simulation of climate change.

Possible improvement of the winds in the Arctic which influence strongly the sea ice distribution.

Improvement of orographic precipitation distributions.

Improved simulations of the ocean/sea ice close to coasts.

I have a Dream!

Remember the famous

Martin Luther King Speech!

AtmosphereModel

Working Group

Ocean ModelWorking Group

Land ModelWorking Group

Polar ClimateWorking Group

PaleoclimateWorking Group

Climate VariabilityWorking Group

BiogeochemistryWorking Group

Climate Changeand AssessmentWorking Group

SoftwareEngineering

Working Group

CCSM SSC

Organization ofCommunity Climate System Model

CCSMAdvisory Board

Future Goals for CCSMFuture Goals for CCSM Improve Existing Climate Simulation

Expand System to Include:

- Biogeochemical Processes

- Atmospheric Chemical Processes

- Ice Sheet Dynamics

- … Expand Outreach and Visibility

Increase Computational Resources

The End