Warren M. Washington NCAR The Parallel Climate Model (PCM) and Transition to a Climate Change Version of the Community Climate System Model (CCSM) Climate Change Simulations u Present and future climate change and assessment simulations u Merged CSM and PCM model u Future research needs u Present and Future cooperation between NSF and DOE Partial List of Distributed Involvement DOE and NSF Supported Project with : u Los Alamos National Laboratory u National Center for Atmospheric Research u Naval Postgraduate School u Oak Ridge National Laboratory u University of Texas, Austin u Scripps Oceanographic Institute u DOE Program on Climate Diagnostics and Intercomparison u U.S. Army Cold Regions Research and Engineering Laboratory u National Energy Research Supercomputer Center u Lawrence Berkeley National Laboratory u Others Contributions to the DOE Climate Change Prediction Program (CCPP) u Develop climate modeling capability that takes advantage of new generation parallel architecture supercomputers u Build on the previous DOE CHAMMP modeling developments u Develop model components and coupled models that can be used for energy policy, IPCC, and future National Assessments History CSM1 and PCM1 u Built for vector/parallel Computers system u Atmosphere: CCM3 u Ocean component: NCAR ocean model u Sea ice dynamics of Flato-Hibler dynamics and simplified thermodynamics u Built for distributed parallel Computer system u Atmosphere: CCM3 u Ocean component: LANL Parallel Ocean Program (POP) u 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 u Agreement to use the same model components u CSM, PCM, and DOE lab staff will develop a merged flux coupler b ongoing SciDAC team of NCAR and DOE laboratory involvement u Full merger occurs when the CCSM is available for climate change simulations and the new flux coupler u 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) ATMOSPHERE COUPLER ATMOSPHERE OCEAN SEA ICE RIVERTRANSPORT LAND/VEGETATION RIVERTRANSPORTCOUPLERLAND/VEGETATION OCEAN TIMETIME TIMETIME Coupled System Processor Layout PCM CCSM2 Target? CSM1 10/24/2001 Simulated Years per Wallclock Month64pes PCM Version 1 - NERSC Machines T3D T3E-600 T3E-900 IBM SP WHI IBM SP WHII Simulated Years Year IBM SP NHII David Pierce Scripps Institution of Oceanography Examples of Climate Change Experiments u Greenhouse gases u Sulfate aerosols (direct effect) u Stratospheric ozone u Land surface changes u Volcanic forcing u Solar change forcing u Carbon soot aerosol (Indian-Asian region) u Various energy/emissions use strategies PCM Historical and Future Simulations u Use of CSM greenhouse gas and sulfate aerosol forcing u 1870 control simulation u Historical 1870 to present u IPCC Business as Usual assumption u IPCC stabilization assumption u Ensemble of 10 for Historical, BAU/STAB ensemble 5 u Solar variability simulation-ensemble of 4 u 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: PCM and CSM Presence in the International Climate Modeling Community Interim Model: PCM-CSM Transitional Model (PCTM) u POP with GM and KPP (LANL, NCAR, NPS), R. Smith grid modifications (LANL) u C. Bitz sea ice multi-thickness(5) distribution thermodynamics and E. Hunke et al. elastic viscous plastic dynamics (U. of Washington, LANL, NCAR) u River Transport, Branstetter and Famiglietti (U. Of Texas, Austin, NCAR) Future Developments and Simulations u More simulations with Black Carbon distributions in PCM1 over entire globe u Higher resolution atmosphere -T85d simulations u Improved archival and cataloging of large data sets - EARTHGRID/DOE/ u Simulations related to DOE mission on energy use impacts on the climate system - ACPI demonstration project u Work with statistical community on signal to noise u CCSM2 climate change simulations early next year Why T85? u Improved regional simulation of climate change. u Possible improvement of the winds in the Arctic which influence strongly the sea ice distribution. u Improvement of orographic precipitation distributions. u Improved simulations of the ocean/sea ice close to coasts. I have a Dream! Remember the famous Martin Luther King Speech! Atmosphere Model Working Group Ocean Model Working Group Land Model Working Group Polar Climate Working Group Paleoclimate Working Group Climate Variability Working Group Biogeochemistry Working Group Climate Change and Assessment Working Group Software Engineering Working Group CCSM SSC Organization of Community Climate System Model CCSM Advisory Board Future Goals for CCSM u Improve Existing Climate Simulation u Expand System to Include: -Biogeochemical Processes -Atmospheric Chemical Processes -Ice Sheet Dynamics - u Expand Outreach and Visibility u Increase Computational Resources The End