The Weather Generator project of the Biospheric Aspects of the Hydrological Cycle (BAHC), an activity of the International Geosphere Biosphere Programme (IGBP), grew out of concerns that General Circulation Models (GCMs) had some shortcomings. In establishing the program, IGBP ecologists and hydrologists hope to be able to downscale weather and climate information to meaningful spatial and temporal scales.
One of the start-up tasks of the Weather Generator project is the identification of the modeling needs of ecosystem modelers. Other key tasks include making coarse scale 0CM output data (about one point every 500 km) into higher spatial resolution output data. The resolution goal is the level of existing observational networks (one point about every 50 km). At the same time, the project aims to provide the variables that ecologists and hydrologists really want. In the next task level, coarse scale observational data (stations roughly every 50 km) will be downscaled to the 1 to 10 km level.
The Weather Generator project proposes to:
- Define, jointly with GCTE and the other foci of BAHC, the ingredients of a Weather Generator
- Coordinate the development, jointly with contributing projects, of methods to downscale the coarse-scale information of global models into the scales needed for ecosystem and hydrologic research
- Test the results of this downscaling procedure with simulated and empirical data sets of present-day climate
- Facilitate distribution and use of the Weather Generator and associated data sets. It is the responsibility of BAHC to direct Focus 4 research and coordinate worldwide efforts in this area.
Improvements are expected in both the low-resolution data used to drive the Weather Generator and the collection of algorithms comprising it. These improvements will be reported annually in the BAHC Newsletter. The first report issued (set for completion spring 1993) will contain a compendium of currently existing algorithms. An internal publication, for members of BAHC-Focus 4, will be distributed on a semi-annual basis. As part of this task, BAHC-Focus 4 will endeavor to establish linkages with and between the climate community and the community of potential users to strengthen the project and accelerate its development.
In 1993, Focus 4 will hold a meeting and a workshop, and write the IGBP proposal for the Weather Generator. A Weather Generator would have obvious value for LTER if the sites use 0CM output data in their site ecosystem studies.
Bruce Hayden (Virginia Coast Reserve) is serving as a member of Focus 4. The CED Bulletin, a periodic bulletin board on LTERnet, will serve as the LTER forum for IGBP-BAHC Focus 4 activities. Contact: Bruce P. Hayden, Department of Environmental Sciences, Clark Hall, University of Virginia, Charlottesville, VA 22903, 804- 924-0545/7761, bph@LTERnet.edu (Internet).