1. Department of Physics; Imperial College London; London UK
2. Department of Astrophysical and Planetary Sciences; University of Colorado Boulder; Boulder Colorado USA
3. Laboratory of Atmospheric and Space Physics; University of Colorado Boulder; Boulder Colorado USA
4. National Center for Atmospheric Research; Boulder Colorado USA
5. South West Research Institute; San Antonio Texas USA
6. NASA Goddard Space Flight Center; Greenbelt Maryland USA
7. IRF Swedish Institute of Space Physics; Uppsala Sweden
8. Laboratoire de Physique des Plasmas; Paris France
9. School of Electrical Engineering; KTH Royal Institute of Technology; Stockholm Sweden
10. Space Research Institute; Austrian Academy of Sciences; Graz Austria
11. Department of Earth, Planetary, and Space Sciences; University of California; Los Angeles California USA
12. Department of Physics; University of New Hampshire; Durham New Hampshire USA