PROGRAM TITLE: Tropical Ocean & Global Atmosphere (TOGA) ACTIVITY STREAM: Process, Data, Model, Observe, Assess SCIENCE ELEMENT:Climate and Hydrologic Systems NATIONAL SCIENCE FOUNDATION SCIENTIFIC MERIT: TOGA's objective is to investigate seasonal-to- interannual variability of the coupled tropical ocea-global atmosphere system in order to determine and understand its predictavility and to apply this knowledge to operational climate prediction. The TOGA emphasis has been in the Pacific where primary interannual signal, ENSO (El Nino Souther Oscillation), is the strongest. The best known ENSO phenomenon is the stron warming of coastal waters off the west coast of South America, which has significant and frequently devastating effects on local fisheries and which may affect both local and global weather and climate patterns, particularly precipitation and storm patterns. The TOGA Program ddresses its objectives with process tudies to investigate specific mechanisms of air-sea interaction, research on coupled ocean-atmosphere models, and an observational system that now routinely monitors the equatorial Pacific. For example, the ability to watch the development of the 1986-87 event was impressive and unprecedented. This real-time monitoring system is expected to continue as part of the Global Ocean Observing System. TOGA COARE (Coupled Ocean- Atmosphere Response Experiment) recently completed a highly successful international (18 countries) field project. TOGA COARE examined ocean- atmosphere exchanges over the wester Pacific warm pool where ENSO events originate. TOGA advances also include the demonstration of a modest but useful predictive capability for ENSO and the establishment of the rudimentary elements of an operational data assimilation and prediction system. As the ten year (1985-1994) TOGA program comes to an end, national and international plans call for follow-programs to build on its successes. Internationally, CLIVAR (A Study of CLImate VARiability and Predictability) is a new WCRP Program designed to extend the research emphasis on climate variability and predictability to the global domain over short (seasonal-to- interannual) and long (decadal-to-century) time scales. Nationally, GOALS (Global Ocean-Atmosphere-Land System) is proposed as the US contribution to the seasonal-to-interannual focus of CLIVAR. Oversight and evaluation of the US component of the program is provided through the TOGA Panel and the Climate Research Committee of the National Academy of Sciences. STAKEHOLDERS: In the U.S., the principal players are NOAA and NSF, with NASA contributing to studies of surface fluxes and coupled ocean-atmosphere models and ONR contributing to process studies. Internationally, TOGA is a major element of the World Climate Research Program (WCRP) of the World Meteorological Organization (WMO) and the International Council of Scientific Unions (ICSU). It is also supported by UNESCO's Intergovernmental Oceanographic Commission (IOC) and ICSU's Scientific Committee on Oceanic Research (SCOR). Fifteen countries are now on record as primary contributors to TOGA. Representatives of the international community met in Geneva in May, 1986, to discuss potential commitments for resources to be applied to WCRP programs, including TOGA. An Intergovernmental TOGA Board (ITB) was subsequently approved by both WMO and IOC, with responsibility for implementing these commitments. The primary beneficiaries are the Natural Resources (agriculture and fisheries) managers of all the countries located within the tropics. POLICY RELEVANCE: Direct benefits have been demonstrated for U.S. and international policymaking related to the climate's natural variability and its impacts on societal structures. For example, short-term (6 months to a year) ENSO predictions are now used by several countries to reduce crop failures and livestock death due to sever droughts. Measurements of sea level changes have proven to be a useful predictor of fishery abundance around the Hawaiian Islands. Improved predictions of the frequency of tropical storms in relation to El Nino should be of interest to coastal states. PROGRAM CONTACTS:Eric Itsweire, Physical Oceanography Associate Program Director Donna Blake, Climate Dynamics Associate Program Director