Структура и динамика полярных токовых систем : материалы международного симпозиума «Полярные геомагнитные явления», 25-31 мая, Суздаль, СССР / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т. – Апатиты : [б. и.], 1988.

center of the figure. We have superimposed the cross-track component of the perturbation magnetic field onto the image of the aurora and corrected its horizontal position for field line mapping from the spacecraft altitude (800 km) to that of the emissions (110 km). The HILAT trajectory is marked by the solid line through the center of the image and north is to the left. The cross-track component of the plasma drift as measured by the 1Ш is plotted along the bottom of the image. Positive and negative velocities are roughly west and east respectively. Л В (nT) 0 Pig. 2. An expanded view of the auroral image shown in F i p . 1 with tho cross-track component of the disturbance magnetic field superimposed. The spacecraft trajectory is through the center of the image. Note the field aiigned current pairs and corresponding gradients in the cross-track ion Йапе In И Й ! P°intS 1 ^ 2 den°te regi°n to be “ M * 4 to the eqSatoSial The magnetic, field trace begins a negative (westward) excursion at about 10:21:40 UT that extends to about 10:23:05 UT. This negative defle c t i o n corresponds to an earthward-directed Region 1 current with a density of approximately 0.7 Ц А/тг . Embedded within the Region 1 current is a series of three pairs of upward and downward directed small-scale Birkeland currents. The location of these current pairs and corresponding g radients in the ion drift velocity are shown by the dashed lines. The upward directed currents are centered at 10:22:20 UT, 10:22:35 UT, and 10:22:45 UT. E a c h £ -800 UT 10 : 21:40 C&LAT 72° MLT 4.0 50