Organization: Department of Energy (DOE)

Research Title: Computer Hardware, Advanced Mathematics and Model (CHAMMP) Climate Model Development Program

Funding Level (millions of dollars):

FY94 10.3
FY95 10.3
FY96 10.8

Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Research Subcommittee (100%)
(b) Environmental Issue: Climate Change (50%); Natural Variability (50%)
(c) Research Activity: System structure and function: Prediction (100%)

Organizational Component:
Environmental Sciences Division
Office of Health and Environmental Research
Office of Energy Research, ER-74
U.S. Department of Energy
Washington, DC 20585

Point of Contact:
David C. Bader
Phone: 301-903-4328

Research Goals:
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.

Research Description:
Program activities are grouped into four interrelated activities:

1. Theoretical studies of decade to century climate change and climate variability. (15%): Studies are currently underway 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, including the procurement of computer resources on leading edge parallel supercomputers. (60%): It is currently assumed that climate change studies and assessments will be carried out with large atmospheric and ocean general circulation models (GCMs) that form the foundation of the most sophisticated climate models. Research done under (1) above will critically evaluate this assumption. CHAMMP is the most active program 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. This core set of models provides the foundation for testing and utilizing the improvements done under (3) and (4) below.

3. New numerical methods and model formulations. (15%): Research into new and better numerical techniques as well as improvement to existing methods used in atmospheric and ocean general circulation models is underway. The initial impetus for this effort was the evolution of massively-parallel supercomputers that could be used for scientific and engineering applications. Realization of the potential power of these new architectures, however, required different algorithmic approaches than those that were developed for vector supercomputers. Nevertheless, researchers experienced in numerical methods and computational fluid dynamics, but new to GCM codes, have taken a critical look at existing techniques and improved upon vector supercomputer-based models as well. Their interest has reactivated a dormant research area that is needed to advance GCM development.

4. Better process parameterizations for GCMs. (10%): 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. This research area also provides the link and overlap with the Atmospheric Radiation Measurement (ARM) program.

Program Interfaces:
The CHAMMP program is the model development component of DOE's comprehensive climate modeling research program that includes climate model diagnosis and prediction of climate change from increasing greenhouse gas concentrations. Through research collaborations at the National Center for Atmospheric Research, the Naval Postgraduate School, the Los Alamos National Laboratory, the Geophysical Fluid Dynamics Laboratory and several universities, it is complementing both NSF's and NOAA's climate modeling programs emphasizing decade to century climate prediction. The program is also tightly linked to DOE's component of the Federal High Performance Computing and Communications Program through the High Performance Computing Research Centers at Los Alamos and Oak Ridge National Laboratories.

Program Milestones:
1994: Adopt 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 to perform coupled model runs as part of the 1994 assessment. 1994: Complete and validate highly optimized atmosphere and ocean GCM codes that can be run on massively parallel scientific supercomputers for use in climate change studies. These models will be both more accurate and computationally more efficient than existing models. 1996: Complete coupled atmosphere-ocean-land surface-sea ice models based on these next generation component models and make them ready for use in climate prediction and climate change assessments.

Policy Payoffs:
More accurate climate prediction tools that take advantage of the most current computing technology will be available to the climate research community. These tools will enable better evaluations of climate change response strategies as well as provide an assessment of natural climate variability on decade and longer scales for long-term planning.