1 Goddard Laboratory for Atmospheric Sciences, NASA/Goddard Space Flight Center, Greenbelt, MD 20771.
2 National Center for Atmospheric Research, Boulder, CO 80307. (The National Center for Atmospheric Research is funded by the National Science Foundation.)
3 Department of Meteorology, Pennsylvania State University, University Park, PA 16802.
4 NOAA/WPL, Boulder, CO 80302.