1. Department of Physics and Astronomy; George Mason University; Fairfax Virginia USA
2. Max Planck Institute for Solar System Research; Göttingen Germany
3. Space Sciences Laboratory; University of California; Berkeley California USA
4. Institute of Astrophysics; Georg-August University; Göttingen Germany
5. NASA Goddard Space Flight Center; Greenbelt Maryland USA
6. Department of Geophysics; Tohoku University; Sendai Japan
7. Laboratory for Atmospheric and Space Physics; University of Colorado Boulder; Boulder Colorado USA