1. Space Research Institute, Austrian Academy of Sciences, 8042 Graz, Austria
2. The Earth Physics Department, Saint Petersburg State University, 198504 Petrodvoretz, Russia
3. Institute of Computational Modelling, Siberian Branch of the Russian Academy of Sciences, 660036 Krasnoyarsk, Russia
4. The Applied Mechanics Department, Siberian Federal University, 660041 Krasnoyarsk, Russia
5. Theoretical Physics Division, Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
6. KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden