Affiliation: | (1) Polar Geophysical Institute, Murmansk Region, 184200 Apatity, Russia;(2) Insitute of Applied Physics, 603600 Nizhny Novgorod, Russia;(3) The University of Alabama, Huntsville, USA;(4) LPCE/CNRS, Orleans, France;(5) Geophysical Observatory, Sodankylä, Finland |