1. Associate professor in the Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri 63130.
2. Senior research associate in the Department of Earth and Planetary Sciences, Washington University, St. Louis, Missouri 63130.
3. Geologist with the U.S. Geological Survey, Menlo Park, California 94025.
4. Meteorologist in the Department of Atmospheric Sciences, University of Washington, Seattle 98195.
5. Research engineer at the Jet Propulsion Laboratory, Pasadena, California 91109.