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