1. The Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
2. Institute for Geophysics and Extraterrestrial Physics; Technical University of Braunschweig; Braunschweig Germany
3. Max Planck Institute for Solar System Research; Katlenburg-Lindau Germany
4. Institute of Geophysics and Planetary Physics and Department of Earth and Space Sciences; University of California; Los Angeles California USA
5. Space Sciences Laboratory; University of California; Berkeley California USA
6. Department of Atmospheric and Oceanic Sciences; University of California; Los Angeles California USA
7. NOAA Space Weather Prediction Center; Boulder Colorado USA