1. Space Science Institute Boulder Colorado USA
2. Goddard Planetary Heliophysics InstituteUniversity of Maryland College Park Maryland USA
3. NASA Goddard Space Flight Center Greenbelt Maryland USA
4. Southwest Research Institute San Antonio Texas USA
5. Harvard Smithsonian Center for Astrophysics Cambridge Massachusetts USA
6. Department of Atmospheric, Oceanic, and Space SciencesUniversity of Michigan Ann Arbor Michigan USA