PROGRAM TITLE: Climate Variability and Predictability (CLIVAR) ACTIVITY STREAM: Process Research SCIENCE ELEMENT:
Climate and Hydrologic Systems DEPARTMENT OF COMMERCE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATIONDESCRIPTION: The Program on Climate Variability and Predictability (CLIVAR) is a study under the World Climate Research Program to determine the variability and predictability of the physical climate system on time scales of seasons to a century. It is divided into two research foci by time scale. CLIVAR Focus 1 deals with climate variability on seasonal to interannual time scales, building on the scientific heritage of the Tropical Ocean-Global Atmosphere (TOGA) program. The U.S. contribution to Focus 1 will be the Global Ocean-Atmosphere-Land System (GOALS) program. GOALS is intended to build upon the base El Nino/Southern Oscillation (ENSO) research of TOGA to extend predictability of seasonal to inter- annual fluctuations beyond the tropical Pacific and will include the effects of the other tropical upper oceans, higher latitude upper oceans, and land surface processes. Together with NOAA's GEWEX program, GOALS will initiate a North American Precipitation Study to focus on modeling and predicting monsoonal processes over the North American continent in response to upper ocean and land system forcing. This program represents the only concentrated U.S. effort to develop models for fore-casting seasonal to interannual precipitation anomalies like those in the Midwest this summer, seasons to years in advance. CLIVAR Focus 2 deals with decadal to centennial time scales. One major U.S. contribution to CLIVAR (2) will be the Atlantic Climate Change Program (ACCP). Following up on the results of both climate models and studies of climate variability over the last 12,000 years, ACCP is designed to determine the sensitivity of the global climate system on long time-scales to variability in Atlantic Ocean circulation patterns and air/sea fluxes, pursuing the hypothesis that such circulation patterns may be a dominant feature of interdecadal climate change. ACCP consists of: 1) the analysis of historical data; 2) interpretation of data through models, and 3) development of long- term monitoring programs for the Atlantic. NOAA is also participating in the World Ocean Circulation Experiment (WOCE), in which the U.S. contribution is currently focusing in the Pacific. Preparations are underway for NOAA participation in the WOCE Indian Ocean Expedition in 1995. Both the ACCP and TOGA programs have been reviewed by the NOAA Panel on Climate and Global Change, an independent committee of NOAA and academic scientists. In its October 1992 review, it concluded "The TOGA program has a long and successful history. There has been good close contact between the academic community, NOAA, and the international community. TOGA and stratospheric ozone chemistry are two successful examples of global change issues that matured to produce useful policy links." The Panel also concluded that ACCP "represents a bold and successful initiative by NOAA that involves a broad community both within NOAA and the academic sector and crosses all aspects of planning and implementation." STAKEHOLDERS: Internationally, CLIVAR is sponsored and coordinated by WCRP. In addition, it will represent a major NOAA contribution to the Intergovernmental Panel on Climate Change. As is noted in their FY95 submissions, NOAA and NSF are partners in the support of GOALS as a follow-on to the TOGA program, as well as WOCE. Both programs are coordinated nationally through the NAS Climate Research Committee, where a CLIVAR Panel is now being established. SHORT-TERM POLICY PAYOFFS: This program's aim to understand and predict variations in the natural climate system provides important input to IPCC deliberations on the impact of anthropogenic climate forcing. Contributions to climate change from human activity can only be understood in the context of the naturally varying system. The sustained rainfall over the Midwest and subsequent flooding this Summer provide a vivid example of the results of subtle shifts in planetary- scale circulation features on seasonal to interannual timescales. The CLIVAR program is designed to provide decisionmakers an assessment of the ability to predict such climatic events in advance and whether such events are spurious anomolies or an artifact of transition to a new climate regime. Recent ice core records from Greenland indicate that during periods when the Earth was slightly warmer than today, the climate regime was characterized by abrupt changes of 10-140C. The most obvious explanation is rooted in changes in ocean circulation. This suggests that the planet's response to greenhouse forcing will likely not be monotonic global warming, but potentially unstable climate. Early insights from these studies will be factored into the IPCC Assessments in 1995 and beyond. PROGRAM CONTACT: David Goodrich, Office of Global Programs, 1100 Wayne Avenue, Silver Spring, MD 20910, (301) 427-2089 X38.