USDA, Russia, NASA and Others Team Up To Give Earth a Physical Exam

This past summer, a large swatch of Oklahoma served as a test patient for a future complete physical examination of the planet as part of NASA's "Mission to Planet Earth." The project in Oklahoma, named the Southern Great Plains 97 (SGP97) project, focused on soil moisture and its possible effects on world weather.

It was a cooperative effort between NASA and several other federal agencies, led by Tom Jackson of the Hydrology Laboratory operated by USDA's Agricultural Research Service in Beltsville, Md.

Jackson's interest in the project is in helping farmers plan crop irrigation through more accurate weather predictions.

As part of an international fleet of six planes and 15 satellites, including the Russian Mir space station, a U.S. and Canadian plane flew into so-called "atmospheric boundary layers" between warm and dry air and cool and wet air. These layers happen when air passes over dry or wet land.

The core of the experiment, an experimental soil microwave sensor suspended in the bomb bay of NASA's P-3B aircraft, worked so well itmay become standard in future NASA satellite launches. It's essentially like the skeleton of an umbrella, with 3-foot-long sticks unfurling to do the work of what would otherwise be a large, heavy antenna. The antenna senses natural microwave emissions from the earth. The weaker the emissions, the wetter the soil.

An article on the SGP97 project appears in the April issue of ARS' Agricultural Research magazine. The article is also on the World Wide Web at:

http://www.ars.usda.gov/is/AR/archive/apr98/worl0498.htm

Scientific contact: Thomas J. Jackson, Hydrology Laboratory, Beltsville, Maryland, phone (301) 504-8511, fax (301) 504-8931, tjackson@hydrolab.arsusda.gov.