1. Space Science Center; University of New Hampshire; Durham New Hampshire USA
2. Instituto de Fisica del Plasma; CONICET and Universidad de Buenos Aires; Buenos Aires Argentina
3. Departamento de la Fisica; Pontificia Universidad Catolica Argentina; Buenos Aires Argentina
4. Department of Physics; University of Oslo; Oslo Norway
5. Department of Physics and Astronomy; University of Leicester; Leicester UK
6. Avadh Bhatia Physics Laboratory, Department of Physics; University of Alberta; Edmonton Canada
7. NOAA Space Environment Center; Boulder Colorado USA
8. Geomagnetism and Space Physics Program; Danish Meteorological Institute; Kobenhavn Denmark