The US CLIVAR Program

Building on the successes of previous scientific programs such as TOGA, WOCE, and many other contributory efforts, the Climate Variability and Predictability (CLIVAR) science program offers the United States an opportunity to cooperate in a comprehensive study of climate variability and change. This World Climate Research Program (WCRP) project aims to understand the causes of climate variability and to improve predictability of this variability. The CLIVAR program is conveniently divided into multiple areas of research than can be grouped conveniently according to time scale. Investigations into phenomenon on time scales from seasonal-to-interannual are focused primarily, but not exclusively, on the Pacific region. For longer time scales, ie decadal-to-centennial, CLIVAR is focused on the Atlantic region, but clearly must also consider interactions with higher-latitudes. Finally, identifying and understanding natural and anthropogenic sources of climate change are of interest for the longest time scales. Collectively, the breadths of these areas of emphasis underscore the need to understand the complex interactions between the atmosphere, ocean, land, and ice.

While the time scale distinctions between season-to-interannual and decadal-to-centennial have helped frame the initial science questions to be addressed, the importance of the interaction of the variability across time scales is sufficiently compelling to consider enhancing predictive capabilities on multiple time scales and to apply forecasts on regional spatial scales. Within the US, this regional approach has been adopted, fully recognizing that many obstacles must still be overcome to fully engage scientists from multiple disciplines and subsequently organize the numerous scientific activities to take full advantage of contributed efforts.

There are several tools, resources, and overarching requirements that must be addressed for they form the foundation upon which activities can be built to achieve CLIVAR objectives. The design and implementation of a sustained climate observing systems, continuation of key satellite observations, and development of qualified datasets that extend climate records into the past are essential for diagnostic, modeling, and climate monitoring activities. The evolution of models, data assimilation techniques, and other integration tools provides the framework for understanding and exploring the climate system.

This presentation will provide an overview of the US CLIVAR program, highlighting its scope and objectives as well as the developing plans for implementation.