1. Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
2. IRAP; Toulouse France
3. Southwest Research Institute; San Antonio Texas USA
4. Department of Physics and Astronomy; University of Texas at San Antonio; San Antonio Texas USA
5. NASA Goddard Space Flight Center; Greenbelt Maryland USA
6. Applied Physics Laboratory; The Johns Hopkins University; Laurel Maryland USA
7. Jet Propulsion Laboratory; Pasadena California USA
8. Istituto di Astrofisica e Planetologia Spaziali; INAF; Rome Italy
9. Laboratory for Atmospheric and Space Physics; University of Colorado Boulder; Boulder Colorado USA
10. Department of Astrophysical Sciences and Office of the Vice President for the Princeton Plasma Physics Laboratory; Princeton University; Princeton New Jersey USA
11. LESIA; Observatoire de Paris; Meudon France