We report the initial results of the statistical analysis of field-aligned currents (FACs) observed above the ionosphere by the low-Earth polar-orbiting Swarm satellite. FACs are the main electrodynamic agent of the solar wind-magnetosphere-ionosphere coupling. FACs flow along the high-conducting geomagnetic field lines between the magnetospheric boundary layers and the auroral ionosphere. A series of the Swarmbased statistical maps of large-scale FACs are constructed, resolving the seasonal dependences of the FAC distribution under conditions of the northward and southward interplanetary magnetic field (IMF), low solar activity and the total IMF strength of 1-2 nT on average. The conventional R0/R1/R2 system is the dominant feature in the dark and sunlit polar ionosphere. The upward/downward current densities are well balanced within a given hemisphere, demonstrating a reasonable rate of elevation, going from winter to summer and from positive to negative IMF. The FAC intensities are larger by a factor of 1.6 in the summer hemisphere in comparison to the winter hemisphere. KEYWORDS: solar wind-magnetosphere-ionosphere interaction; field-aligned currents; statistical maps; Swarm satellites.
Original language | English |
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Article number | ES6007 |
Journal | Russian Journal of Earth Sciences |
Volume | 18 |
Issue number | 6 |
DOIs | |
State | Published - 27 Dec 2018 |
Externally published | Yes |
ID: 49748547