Research Title: Climate Variability and Predictability (CLIVAR)
Funding Level (millions of dollars):
Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Research Subcommittee (100%)
(b) Environmental Issue: Natural variability (100%)
(c) Research Activity: System structure and function: Understanding (100%)
Office of Global Programs
1100 Wayne Ave., Suite 1225
Silver Spring, MD 20910
Point of Contact:
Phone: 301 427-2089
To determine the variability and predictability of the physical climate system on time scales of seasons to a century
CLIVAR's objectives are to (i) describe and understand the physical processes responsible for climate variability and predictability on time scales ranging from seasonal to centennial, (ii) extend the record of climate variability of these time scales of interest, and (iii) extend the range and accuracy of seasonal to interannual climate prediction through the development of global coupled models.
CLIVAR is organized around three science thrusts: 1. Climate variability and predictability from seasons to years; 2. Climate change and the world ocean; and 3. Human impacts on climate.
Thrust 1 will be implemented in the US through a new science initiative, the Global Ocean-Atmosphere-Land System (GOALS) program. GOALS builds upon and broadens the scope of TOGA from the tropical Pacific to the global tropics and eventually the entire globe. The objective of GOALS is to understand global climate variability on seasonal-to-interannual time scales, to determine the spatial and temporal extent to which this variability is predictable, to develop the observational, theoretical and computational means to predict this variability, and to make enhanced predictions. The central hypothesis of GOALS is that variations in sea-surface temperature, soil moisture, sea ice and snow exert a significant influence on seasonal-to-interannual climate variability and its predictability. GOALS is intended to build upon the base El Niño/Southern Oscillation (ENSO) research of TOGA to extend predictability of seasonal to interannual fluctuations beyond the tropical Pacific and will include the effects of the other tropical upper oceans, higher latitude upper oceans, and land surface processes. In FY 1995, GOALS will initiate a Pan American Climate Studies (PACS) program to focus on modeling and predicting monsoon processes and precipitation over the Americas in response to upper ocean and land system forcing.
Thrust 2, CLIVAR DECCEN, will focus on decadal and longer variability and its underlying causes. Included will be fundamental research on atmosphere-ocean interactions, the mechanisms underlying decadal and longer variability, the global ocean circulation (water mass formation, interocean exchanges, and ocean basins) and projects designed to organize and synthesize observations of decadal climate variability. A major U.S. contribution 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 are 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 Indian Ocean. Preparations are underway for a joint Atlantic Circulation and Climate Experiment with NSF and European nations in 1996-97.
Internationally, CLIVAR is sponsored and coordinated by the World Climate Research Program (WCRP) and will represent a major scientific contribution to scientific assessments by Intergovernmental Panel on Climate Change (IPCC). CLIVAR has a particularly important interface with the Global Energy Water Cycle Experiment (GEWEX) in parameterizing land surface and subgrid-scale processes in climate models. NOAA will continue to involve the academic community in the planning and conduct of CLIVAR science. NOAA will seek advice on scientific planning for CLIVAR from the National Academy of Sciences and will seek interagency partnerships primarily with NSF, NASA and DOE to implement the program.
Summer, 1994: Hold international two-week workshop to analyze data on ocean- atmosphere interactions in the western Pacific warm pool gathered during four-month intensive field phase of the TOGA Coupled Ocean-Atmosphere Response Experiment. Spring, 1995: Launch PACS program with pilot monitoring efforts in the eastern Pacific and tropical Atlantic, development and analysis of climate datasets for the Americas, and modeling of seasonal to interannual precipitation variability over the Americas; Spring 1996: Complete WOCE Indian Ocean Expedition; Fall 1997: Atlantic Circulation and Climate Experiment completed.
CLIVAR's aim to understand and improve predictions of 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 recent flooding in California and the Midwest provide vivid examples of the results of subtle shifts in planetary-scale circulation features on seasonal to interannual timescales. The CLIVAR program is designed to provide decision-makers an assessment of the ability to predict such climatic events in advance and whether such events are spurious anomalies or an artifact of transition to a new climate regime. Ice core records from Greenland indicate that the Earth's climate can change markedly in periods of a decade or less. The most obvious explanations are rooted in changes in ocean circulation. This suggests that the planet's response to greenhouse forcing likely will not be monotonic global warming, but rather rapid changing or potentially unstable climate. Early insights from these studies will be factored into the IPCC Assessments in 1995 and beyond.