1. Institute of Physics, Mathematics and IT, I. Kant Baltic Federal University, 236041 Kaliningrad, Russia
2. Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Luis Companys, 23, 08010 Barcelona, Spain
3. Institute of Space Sciences (ICE-CSIC), C. Can Magrans s/n, 08193 Barcelona, Spain
4. Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece