1. Polar Geophysical Institute, 184200, Apatity, Murmansk Region, Russia
2. Russian Federal Nuclear Center, 607190, Sarov, Nizhni Novgorod Region, Russia
3. Swedish Institute of Space Physics, S-981 28 Kiruna, Sweden
4. Finnish Meteorological Institute, Fin-00101, Helsinki, Finland
5. Institute of Solar–Terrestrial Physics, 663317, Norilsk, Russia