1. Institute of Geophysics and Planetary Physics and Department of Earth, Planetary and Space SciencesUniversity of California Los Angeles California USA
2. Space Sciences LaboratoryUniversity of California Berkeley California USA
3. Department of PhysicsUmeå University Umeå Sweden
4. Swedish Institute of Space Physics Kiruna Sweden
5. Max Planck Institute Gottingen Germany
6. Faculty of Natural Sciences, Department of PhysicsImperial College London UK