August 27, 2001
Stephen D. Parker,
Director
Water Science and Technology Board
National Research Council
2101 Constitution Ave., NW HA 462 Washington, DC 20418
Dear Dr. Parker:
We are writing to you on behalf of the USGCRP Interagency Working Group on the Global Water Cycle (GWC) to request your assistance in the review of the recently published report, “A Plan for a New Science Initiative on the Global Water Cycle.” At the request of the Subcommit-tee on Global Change Research and with the support of the USGCRP agencies, Prof. George Hornberger established a Study Group in 1999 to consider water cycle issues. During the spring of 2001 his group com-pleted their work and the final report was published this summer.
The Water Cycle Study Group was charged with the responsibility of formulating a research strategy and scientific plan for investigating the global water cycle, its interactions with climate, and an enhanced understanding of the fundamental processes that govern the availability and the biogeochemistry of water resources. In short, they were requested to develop the strategy and science plan for a national program. This “Science Plan”is intended to produce:
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A quantitative understanding of atmospheric, terrestrial, and air-sea interactions that govern water and energy cycles on intraseasonal to centennial time scales and on global and regional scales: this includes, inter alia, the roles of water vapor, clouds, and precipitation processes; biogeochemical processes, terrestrial and aquatic ecosystems influences; and the role of surface and subsurface waters within the overall hydrologic cycle;
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An improved representation of these processes in climate and other models, across the relevant spatial and time scales, that will allow simulation of the hydrologic cycle and its interactions with the rest of the earth system;
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An understanding of the response of the water cycle to environmental change and the accompanying impact on water resources;
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A capability to model and, where appropriate, predict variations in global and regional hydrologic processes and water resources on seasonal to interannual time scales and longer time scales; and
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The requirements for comprehensive, systematic spaced-based, ground-based and in situ observations in support of the water cycle science objectives, with consideration of the compatibility of measurements across scales and processes.
The final water cycle report documents the research needs for understanding the Global Water Cycle and recommends three principal initiatives that should be undertaken by USGCRP agencies to address priority science questions. Within the USGCRP we are currently in the prelimi-nary stages of determining how we will approach these scientific prob-lems on an interagency basis. This includes developing implementation strategies and plans and seeking funding for new water cycle initiatives. It would be greatly appreciated if you could coordinate a review of the report that has input from the Committee on Hydrologic Sciences (COHS), the Climate Research Committee (CRC) and any other committees that you may find helpful in providing credible guidance to the USGCRP agencies. The review will be used by the Interagency Global Water Cycle Working Group in developing a consolidated USGCRP implementation plan for the Global Water Cycle.
Thank you for your attention to this matter. If we can be of further help in this process we would be happy to provide additional background information.
Sincerely,
Robert A. Schiffer
Co-Chair
Richard G. Lawford
Co-Chair
USGCRP Interagency Working Group on the Global Water Cycle