[1] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA
[2] Univ Colorado Boulder, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA
[3] NOAA, Earth Syst Res Lab, Chem Sci Div, Boulder, CO 80305 USA
[4] Lamont Doherty Earth Observ, Dept Earth & Environm Sci, Palisades, NY USA
[5] Deutsch Zentrum Luft & Raumfahrt DLR, Inst Phys Atmosphare, D-82230 Oberpfaffenhofen, Weissling, Germany
[6] Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA