PROGRAM TITLE: Climate Diagnostics and Experimental Prediction ACTIVITY STREAM: Modeling SCIENCE ELEMENT:Climate and Hydrologic Systems DEPARTMENT OF COMMERCE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION DESCRIPTION: Predictive understanding of Earth system behavior on time scales of primary human interest (seasons to centuries) is the unifying goal of the USGCRP. NOAA directly addresses this goal with its Climate and Global Change Program which focuses on production of quantitative predictions and reliable assessments of global change and its regional implications on time scales of seasons to a century. The Climate Dynamics and Experimental Prediction (CDEP) project provides an important means for supplying these predictions and assessments on an organized, routine basis. CDEP is designed to employ integrative models as the central tool for achieving constantly improving predictive insight into Earth system behavior and for relating individual research projects of the USGCRP meaningfully to one another. CDEP has four primary areas of interest: coupled model development, climate diagnostics, experimental prediction, and IPCC-related modeling. CDEP now supports a number of critical long-term modeling and diagnostic efforts including the development of an operational climate data assimilation system to supplement the weather-related capabilities of NMC, development, testing, and application of an operational ocean model, the derivation of useful model-based air-sea fluxes, and the historical reanalysis of observed atmospheric fields. CDEP's primary areas of emphasis in FY 1995 and beyond are (i) to establish a broad community-wide coupled model development program in partnership with other agencies, (ii) to strengthen the system of routine experimental climate prediction activities at major U.S. research institutions; and (iii) to serve the assessment needs of the USGCRP through an expanded program of climate diagnostics and analytical studies and explicit contributions to a CEES interagency effort to apply Earth system modeling in support of assessment activities of the IPCC. CDEP will not only develop improved models which effectively represent the interactions of the physical, chemical and biological earth system, but will undertake exploratory efforts at coupling physical and biogeochemical processes with socio-economic processes to study the societal impact of climate change and the effect of human activity on climate. Current climate modeling is severely limited by computer resources, low speed data links, and lack of uniform protocols for model output. CDEP, therefore, includes resources for general improvement in computational infrastructure, in particular, easily usable and available supercomputer time and improved data highways. STAKEHOLDERS: CDEP provides an integrating mechanism for modeling activities that are generated in the process research domain from a number of USGCRP Programs including TOGA, WOCE, GEWEX, ACCP, Atmospheric Chemistry, and Economics. Internationally, CDEP will make important contributions to the Climate System Modeling Program (CSMP)of the WCRP and the Global Analysis, Interpretation and Modeling (GAIM) Program of the IGBP. SHORT-TERM POLICY PAYOFFS: CDEP supports the IPCC process by focussing on short-term improvements in earth system models upon which IPCC assessments are based. With its focus on end-to-end modeling of the interactions between the earth system and human activity, CDEP provides timely predictions as a basis for assessments of natural and forced climate change and an ability to evaluate alternative mitigation and adaptation strategies. PROGRAM CONTACT:Mike Patterson, Office of Global Programs, 1100 Wayne Avenue, Suite 1225, Silver Spring, MD 20910, (301) 427-2089 X12.