University of Potsdam, Institute of Physics and Astronomy, Karl-Liebknecht-Str. 24/25, Potsdam, 14476, Germany; University College London, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, Surrey, RH5 6NT, United Kingdom
Observatoire de Paris, LESIA, Meudon Cedex, 92195, France
University of New Hampshire, EOS Institute - Morse Hall, 39 College Rd., Durham, NH 03824, USA