1. Space Plasma Physics Group, University of Bergen, Bergen 5007, Norway
2. Swedish Institute of Space Physics, Uppsala 75121, Sweden
3. Space Science Center, University of New Hampshire, Durham, New Hampshire 03824, USA
4. Space and Plasma Physics, Department of Physics and Astronomy, Uppsala University, Uppsala 75120, Sweden
5. NASA Ames Research Center, Moffet Field, California 94035, USA
6. Space and Plasma Physics, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 11428, Sweden
7. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA
8. Department of Astronomy, University of Maryland, College Park, Maryland 20742, USA
9. Space and Plasma Physics, School of Electrical Engineering, KTH Royal Institute of Technology, Stockholm 11428, Sweden
10. Southwest Research Institute, San Antonio, Texas 78228, USA
11. Institute of Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Braunschweig 38106, Germany
12. Space Research Institute, Austrian Academy of Sciences, Graz 8042, Austria