Organization: Department of Commerce (DOC)

Research Title: Global Energy and Water Cycle Experiment (GEWEX)

Funding Level (millions of dollars):

FY94 4.9
FY95 5.5
FY96 4.6

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%)

Organizational Component:
Office of Global Programs
1100 Wayne Ave., Suite 1225
Silver Spring, MD 20910

Point of Contact:
Rick Lawford
Phone: 301 427-2089

Research Goals:
The principal goal of the GEWEX program element within the NOAA Climate and Global Change Program is to improve climate prediction through the development of better representations of subgrid-scale processes in climate models.

Research Description:
The major thrust of the program is directed at processes associated with the coupling of energy and water cycles across the land atmosphere interface. One of the major scientific questions to be addressed by the program is, "To what extent is it necessary to model explicitly the effects of the underlying heterogeneous land surface in order to make significant improvements in seasonal to interannual climate predictions?" The GEWEX Continental-scale International Project (GCIP) is the principal initiative through which this research is being supported. The enhanced observing period (EOP) for GCIP, focusing on the Mississippi River Basin, commences in October 1995 and will continue for five years. The research program consists of modeling efforts, diagnostic studies and a number of intensive field phases addressing specific research issues. The effort is underpinned by a coordinated data collection and management system that makes maximum use of existing data centers linked through a common access and service system.

Program Interfaces:
NOAA is working closely with its USGCRP partners also contributing directly and indirectly to the activities of GEWEX and IGBP, including NASA, DOE, USGS, USDA and the NSF. NOAA will also continue to play an active role in national and international planning mechanisms for GEWEX and related programs through its involvement in and support for National Academy, WCRP and IGBP scientific committees and working groups. Particular attention will be given to coordinating studies planned for the continental United States with related programs in Canada, Europe and the countries of Central and South America.

Program Milestones:
Spring 1995: Commence ramp-up of operational phase of GCIP with conduct of a pilot, enhanced seasonal observing period, focused predominantly on the Red River/Arkansas River Basin. October 1995: Commence 5-year GCIP Enhanced Observing Period; Spring 1996: Begin expansion of research activities into the Upper Mississippi where cold region processes become more important.

Policy Payoffs:
Knowledge on water and energy processes gained from studies over the data rich regions of the continental United States can be applied to regions of the earth's surface less well monitored by in situ observing systems. Concurrent advancements in global remote sensing capabilities will lead to improved global climate models, and to greater confidence in assessments of the regional impacts of global change. Enhancing measurements of key climate parameters over the Mississippi River Basin and adjacent areas, coupled with work already in process on improving subgrid-scale parameterizations, will lead to a better understanding of the complex hydroclimatology of the Basin. Improvements in predictive models of the climate system derived from this increased understanding will enable greater specificity in seasonal to interannual predictions of regional climate variability. The body of information dealing with the effects of climate variability and change on hydrological and water resources has grown rapidly in recent years, especially through specific case studies of hydrological impacts. Nevertheless, few water resource policy and management insights have been produced in these efforts. From its inception GCIP has incorporated a water resource assessment component in its structure. This component addresses critical issues of transferring the results of research in the hydrological and meteorological climate sciences to water managers for the ultimate benefit of water users. Questions of importance to water resource assessment and management include: Can climate models reproduce the timing, amount, and regional distribution of snow across the Mississippi River Basin? How well are snowmelt-generated spring flows simulated, and how variable is model skill in simulating runoff over monthly to annual time scales? Are there any significant regional differences in model skill at simulating runoff and related variables across the Mississippi River basin?