1. Swedish Institute of Space Physics; Uppsala Sweden
2. Laboratory of Atmospheric and Space Physics; University of Colorado; Boulder CO USA
3. Space and Plasma Physics, School of Electrical Engineering; KTH Royal Institute of Technology; Stockholm Sweden
4. NASA Goddard Space Flight Center; Greenbelt MD USA
5. Department of Astronomy; University of Maryland; College Park MD USA
6. Space Research Institute; Austrian Academy of Sciences; Graz Austria