1. Department of Meteorology, University of Maryland, College Park, MD 20742.
2. Pacific Northwest Laboratory, Richland, WA 99352.
3. Brookhaven National Laboratory, Upton, NY 11973.
4. National Center for Atmospheric Research, Boulder, CO 80307.
5. National Oceanic and Atmospheric Administration, Boulder, CO 80303.
6. Department of Chemistry, University of Denver, Denver, CO 80210.