Jesper Lindkvist, Umeå University, Umeå, Sweden, Herbert Gunell, Belgian Inst. Space Aeronomy, Brussels, Belgium, Charlotte Goetz, Technical University of Braunschweig, Braunschweig, Germany, Hans Nilsson, IRF Swedish Institute of Space Physics Kiruna, Kiruna, Sweden and Maria Hamrin, Umea Univ, Umea, Sweden