Direct comparison of pulsating aurora observed simultaneously by the FAST satellite and from the ground at Syowa

We have made a direct comparison of a pulsating aurora observed simultaneously from the ground at Syowa in Antarctica and onboard the FAST satellite (∼3100 km altitude). The auroral form appeared as east-west-aligned bands consisting of two different types: a poleward moving pulsation and a standing mode pulsation, each with a period of ∼5 sec. The aurora occurs within the region of an inverted-V structure of lower energy (0.1-1 keV) electron precipitation. The two different types of pulsating aurora are separated in space by a narrow gap in the inverted-V potential structure. Spatial and temporal variations of the down-going high-energy (>5 keV) electron flux show a one-to-one correspondence with the optical pulsating aurora. The down-going high-energy (1-10 keV) ion flux modulation is out of phase (anti-correlated) with the high- energy electron flux modulation. These features suggest that the precipitating high-energy electrons, which produce the pulsating aurora, are modulated by the oscillation of the field-aligned electric field located above FAST.