1. Department of Atmospheric and Oceanic Sciences; University of California; Los Angeles California USA
2. Solar-Terrestrial Environment Laboratory; Nagoya University; Nagoya Japan
3. Earth and Space Sciences/Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
4. Space Sciences Laboratory; University of California; Berkeley California USA
5. Laboratoire de Physique des Plasmas; CNRS/Ecole Polytechnique/UPMC/Paris-Sud 11; St Maur-des-Fossés France
6. Swedish Institute of Space Physics; Uppsala Sweden
7. Laboratory for Atmospheric and Space Physics; University of Colorado; Boulder Colorado USA
8. Institut für Geophysik und Extraterrestrische Physik; Technischen Universität Braunschweig; Braunschweig Germany