The relationship between large scale field-aligned current and monoenergetic auroral electron observed by Swarm satellite

Swarm spacecraft A/C are flying side by side at altitude of 480 km. According to the magnetic field observations from the two crafts, the large scale field-aligned currents can be virtually figured out without the assumption of infinite vertical current chip. In this paper large scale FAC measurements derived from Swarm observations are investigated to explore the spatial and temporal distribution of large scale FAC under various interplanetary magnetic field conditions, as well as the current carriers and their possible source regions. Several novel founding includes: (1) IMF B-z component changes the magnitude of FAC, while FAC structure and distribution are mainly controlled by the B-y component, especially for RO current; (2) At dusk, the correlation between R1 upward current and precipitation was especially high, where the monoenergetic auroral electron is dominated; (3) In the aforementioned area, the density of R1 FAC and monoenergetic electron flux exhibited close linear correlation, suggesting the important contribution of the monoenergetic auroral electron to R1 current at dusk.