Geophysical Institute, University of Alaska Fairbanks, AK, USA

NASA Goddard Space Flight Center, Greenbelt, MD, USA

Center for Atmospheric Research, University of Massachusetts, Lowell, USA

Institute of Space Physics and Applied Technology, Peking University, Beijing, China

Space Sciences Laboratory, University of California, Berkeley, CA, USA

Space Sciences Laboratory, University of California, Berkeley, CA, USA

Institute for Geopysics and Extraterrestrial Physics, TU Braunschweig, Germany

IGPP/ESS UCLA, Los Angeles, CA 90095-1567, USA