Georgia Inst. Of Tech., School of Earth and Atm. Sci., Atlanta, GA 30332

National Center for Atm. Res., Atm. Chem. Div., Boulder, CO 80303

New Mexico State U., Carlsbad Envir. Monitoring Res. Center, Carlsbad, NM 88220

U. of California Irvine, Dept. of Chem., Irvine, CA 92717

U. of New Hampshire, Climate Change Res. Center, Durham, NH 03824

U. of Colorado, Boulder, CO 80303

U. of Arizona, Dept. of Hydrology and Water Resources, Tucson, AZ 85721

NASA-Langley Research Center, Atm. Sci. Div., Hampton, VA 23681

Sonoma Tech and Air Quality Design and Analysis, Golden, CO 80403

NOAA , Aeronomy Laboratory, Boulder, CO 80303