1. Department of Atmospheric, Oceanic and Space Sciences; University of Michigan; Ann Arbor Michigan USA
2. Geospace Physics Laboratory; NASA Goddard Space Flight Center; Greenbelt Maryland USA
3. The Johns Hopkins University Applied Physics Laboratory; Laurel Maryland USA
4. Laboratory for Atmospheric and Space Physics; University of Colorado; Boulder Colorado USA
5. Department of Terrestrial Magnetism; Carnegie Institution of Washington; Washington DC USA
6. Lamont-Doherty Earth Observatory; Columbia University; Palisades New York USA