GEWEX Continental Scale International Project (GCIP)

In Reply Refer To:                                December 6, 1993
Mail Stop 415


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, 

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