GEWEX Continental Scale International Project (GCIP) In Reply Refer To: December 6, 1993 Mail Stop 415 OFFICE OF SURFACE WATER TECHNICAL MEMORANDUM 94.01 Subject: GEWEX Continental Scale International Project (GCIP) The purpose of this memorandum is to advise you of U.S. Geological Survey (USGS) interest and participation in the GEWEX/GCIP hydrologic modeling project, which is getting under way in the Mississippi River basin, and to request your cooperation with the GCIP project team. GCIP (GEWEX Continental Scale International Project) is a central component of the Global Energy and Water-Balance Experiment (GEWEX), which is being conducted by the World Climate Research Program under the auspices of the World Meteorological Organization and the International Congress of Scientific Unions. The USGS and other Federal agencies are participating in the GCIP as part of the U.S. Global Change Research Program. Major goals of the GCIP program include 1) determination of the temporal and spatial variation of water and energy budgets by observations on a continental scale, 2) development and testing of large-scale models of the interactions between land-surface hydrology and the atmosphere suitable for coupling with general circulation models (GCM) and numerical weather prediction (NWP) models, and 3) development and testing of models and procedures for assessing the impact of possible climate variations on water- resources systems. Large and continental scales in this context refer to computational grid-point spacing on the order of several tens of kilometers to a few hundred kilometers. The initial focus of the GCIP is on the Mississippi River basin. This basin was chosen because it is the continental-scale basin that has the best developed observational network, data base, and scientific infrastructure and because of improvements presently underway in the operational observing systems (NEXRAD weather radar, automated-weather observation systems, wind profilers, etc). Although the initial focus of the GCIP is on the Mississippi, the goals of the project are not geographically limited, and it is planned that the project findings and products will be transferable worldwide to similar climatic and hydrological environments. The Mississippi River GCIP is being coordinated with other GCIP studies being planned in the Mackenzie, Amazon, and Baltic Sea basins and in the Asian monsoon region. The Mississippi River GCIP has been in planning and build-up phases for the past three years. A GCIP Science Panel (including Bob Hirsch, George Leavesley, and Harry Lins) has been formed. A scientific plan (1992) and the first volume of a three-volume implementation plan (1993) have been published. The remaining implementation plan volumes are expected to be published early in 1994. Much of the scientific work will be done under grants funded by NOAA; announcements of opportunity have been issued, grant proposals have been received, and the evaluation and funding process is under way. Full scale project operation (the Enhanced Observing Period (EOP)) will take place in 1995-1999. The EOP will be preceded by a GCIP Initial System Test (GIST) in 1994 and will be followed by an integration of the GCIP results into the overall GEWEX project in and after year 2000. GEWEX and GCIP were described in the January 14, 1992, issue of Eos, Transactions of the American Geophysical Union, a copy of which is attached. Additional information about GCIP may be obtained from the International GEWEX Project Office at the address given in the article (telephone 202-863-0012), or from the Office of Surface Water (W. Kirby). A fundamental strategy of GCIP is to make maximum possible use of ongoing operational data-collection and dissemination programs and to maximize coordination and cooperative data sharing with other related investigations. Several U.S. Federal agencies are participating in GCIP by supplying operational data for use by the scientific investigators. Various components of NOAA are supplying satellite data, weather radar data, and other meteorological data and analyses, including outputs from operational numerical weather-prediction models. The Departments of Agriculture and Energy will be furnishing data on soil types, soil moisture, and radiant energy propagation and transformation in the atmosphere and at the surface. The USGS's National Mapping Division will supply digital cartographic and terrain modeling data and land-surface satellite data products. The Water Resources Division and other agencies, such as the Tennessee Valley Authority, U.S. Army Corps of Engineers, and Agricultural Research Service (ARS), will supply streamflow data and other hydrologic and meteorological data. During the EOP, the GCIP investigators will need relatively current streamflow and atmospheric data for use in model calibration, initialization and testing. Annual and cumulative compilations of the data sets that have been collected will be produced. At the end of the EOP, a final composite research quality data set will be produced and turned over to a permanent archiving agency. To make the data available to the scientific investigators, a GCIP data-management system is being developed by the Universities Corporation for Atmospheric Research (UCAR), under the direction of the GCIP Data Collection and Management Committee (DACOM). Because of the tremendous volumes of satellite, radar, and model- output data, the system will make maximum possible use of existing data centers and archives. For efficient access, however, it is being considered to copy some of the smaller data sets into a central GCIP-managed data base. The USGS (and other agencies') hydrologic data base, because of its highly distributed nature, relatively small size, and batch-oriented annual data-approval and publication cycle, is a candidate for copying. It appears that retrievals from the central WATSTORE data base will not satisfy GCIP needs for relatively current data. Therefore, GCIP, UCAR, and the USGS Office of Surface Water (OSW) and NWIS are beginning to investigate data-transfer strategies that will make current provisional data available to the GCIP investigators as rapidly as possible, consistent with USGS quality control and provisional approval procedures and with minimal impact on established operational procedures. Districts with surface-water stations in the GCIP study area will be contacted to work out mutually acceptable arrangements for making their current provisional data accessible to GCIP. The GCIP project and its data management system represent both an opportunity and a challenge to the USGS as the Nation's lead agency for hydrologic data collection and management. I support the efforts of GCIP and UCAR to develop the GCIP data-management system, and request your office's cooperation in this effort. Charles W. Boning, Chief Office of Surface Water Attachment WRD DISTRIBUTION: A, B