Fig. 6

Snapshots of TECP maps at E- (a–d) and F-shell heights (e–h), at various time epochs from 19:30 to 22:00 JST on 23 June 2012 (DOY 175). The subplots in the bottom (i–l) show the 2-D TECP maps obtained by the single-thin-shell approach. Black dashed lines indicate the alignment azimuth of the apparent frontal structures, gray arrows indicate the drift direction, black dots indicate the locations at E and F shells connected by the geomagnetic field line