1. Space Science Center; University of New Hampshire; Durham New Hampshire USA
2. Department of Physics and Astronomy; University of California; Los Angeles California USA
3. Physics Department and Space Sciences Laboratories; University of California; Berkeley California USA
4. Department of Physics and Astronomy; University of Iowa; Iowa City Iowa USA
5. Institute of Geophysics and Planetary Physics; University of California; Los Angeles California USA
6. Department of Physics; University of Oslo; Oslo Norway
7. NOAA National Geophysical Data Center; Boulder Colorado USA
8. NASA/Goddard Space Flight Center; Greenbelt Maryland USA