1. Center for Clouds, Chemistry and Climate, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA.
2. Institute for Terrestrial and Planetary Atmospheres, Marine Science Research Center, State University of New York, Stony Brook, NY 11794, USA.
3. National Center for Atmospheric Research, Boulder, CO 80307, USA.
4. Max-Planck-Institut Fur Meteorologie, Bundesstraβe 55, D-020146 Hamburg, Germany
5. SeaSpace Corporation, San Diego, CA 92126, USA.