TY JOUR TI Statistical maps of field-aligned currents inferred from Swarm: dependence on season and interplanetary magnetic field KW solar wind-magnetosphere-ionosphere interaction KW field-aligned currents KW statistical maps KW Swarm satellites JO Russian Journal of Earth Sciences AU Lukianova, R.Y. AU Bogoutdinov, S.R. PY 2018 IS 18 PB Geophysical Center of the Russian Academy of Sciences