PROGRAM TITLE: Computer Hardware, Advanced Mathematics and Model Physics (CHAMMP) ACTIVITY STREAM: Modeling SCIENCE ELEMENT:Climate and Hydrological System DEPARTMENT OF ENERGY DESCRIPTION: CHAMMP will rapidly advance the science of decade to century climate prediction by expanding the current theoretical basis of climate dynamics and by the continual optimization of computer models that are used for climate prediction and assessment of climate change. Current research emphasis falls under 4 categories: 1. Theoretical studies of decade to century climate change and climate variability that address the natural variability of the ocean and coupled ocean-atmosphere systems on decade and longer time scales. Additional research is aimed at using signal processing theory to identify spatial and temporal patterns in climate data and model results that could identify climate changes. 2. Development of massively- parallel versions of GCMs. Assessments will be carried out with large atmospheric and ocean general circulation models (GCMs) that form the foundation of the most sophisticated climate models. CHAMMP has actively supported efforts to develop and implement versions of existing climate GCM codes on massively-parallel scientific supercomputers. Emphasis is on the development of a baseline set of codes that are both widely used and are representative of the models employed for long term prediction and assessment. 3. Research into new and better numerical techniques as well as improvements to existing methods used in atmospheric and ocean general circulation models is underway. 4. CHAMMP has supported the development of improved process parameterizations that can realistically simulate the effects of these processes on long-term climate change within GCMs. A major emphasis is on the development of modules that have the proper scaling characteristics within the range of GCM resolution used in climate change studies. The program has received extensive peer review including JASONs. STAKEHOLDERS: Major modeling centers (NOAA/GFDL, NCAR) are either directly participating in CHAMMP or are collaborating with CHAMMP researchers to improve models used for climate research and climate change assessment. Climate Change is a major "Grand Challenge" Application focus for the DOE HPCC program. CHAMMP provides a key link between the HPCC and climate modeling research communities that accelerates the application of HPCC research to climate modeling. SHORT-TERM POLICY PAYOFFS: The Semtner-Chervin global ocean model, which is substantially supported by CHAMMP, and the NCAR Community Climate Model Version 2 (CCM2), which is partially CHAMMP supported, have been adapted by NCAR researchers to perform coupled model runs as part of the next integrated assessment. Highly optimized modeling codes that can be run on massively-parallel scientific supercomputers are nearly completed. These models will form the foundation for future climate change simulations used for integrated assessment. PROGRAM CONTACT:David Bader, DOE, ER-74, Washington, D.C. 301-903- 4328