Author Institution: Department of Physics, College of William and Mary, Williamsburg, VA 23187, U.S.A.; Science Directorate, NASA Langley Research Center, Hampton, VA 23681, U.S.A.; Pacific Northwest National Laboratory, Richland, WA 99352, U.S.A.; Laboratoire Interuniversitaire des Systems Atmospheriques, C.N.R.S., UMR 7583; Universites Paris Est et Paris 7, 94010 Cretiel Cedex, France; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, U.S.A.; Dept. of Physics, Astronomy and Geophysics, Connecticut College, New London, CT 06320, U.S.A.