1. Space and Atmospheric Physics Group Department of Physics Imperial College London London UK
2. Space Science Institute Boulder CO USA
3. NASA Goddard Space Flight Center Greenbelt MD USA
4. Department of Mathematics and Statistics University of St Andrews St Andrews UK
5. Institut fï¿œr Geophysik und extraterrestrische Physik TU Braunschweig Braunschweig Germany
6. Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg VA USA
7. High Altitude Observatory National Center for Atmospheric Research Boulder CO USA