Department of Earth and Environmental Sciences, Lamont Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964 United States
Depatment of Applied Physics and Applied Mathematics and Department of Earth and Environmental Sciences, Columbia University, S.W. Mudd, Room 217, New York, NY 10027 United States
Department of Marine, Earth and Atmospheric Sciences North Carolina State University, Campus Box 8208 1125 Jordan Hall, Raleigh, NC 27695
NOAA/Aeronomy Laboratory, Aeronomy Laboratory R/AL3 325 Broadway, Boulder, CO 80305-3328 United States