1. Mullard Space Science Laboratory; University College London; Dorking Surrey UK
2. Massachusetts Institute of Technology; Kavli Institute for Astrophysics and Space Research; Cambridge Massachusetts USA
3. Department of Atmospheric, Oceanic and Space Sciences; University of Michigan; Ann Arbor Michigan USA
4. LESIA, Observatoire de Paris, CNRS, UPMC, Université Paris 6; Université Paris Diderot; Meudon France
5. Institute of Space and Astronautical Science; Japan Aerospace Exploration Agency; Kanagawa Japan
6. Space and Atmospheric Physics, Blackett Laboratory; Imperial College London; London UK
7. Southwest Research Institute; San Antonio Texas USA