Исследование стационарной магнитосферной конвекции / В. А. Сергеев [и др.] ; Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т. – Препр. ПГИ 86-05-47. - Апатиты : Кольский филиал АН СССР, 1986.

Vorobjev (1979) showed permanent presence of such a bulge at 70-72°Л near midnight, which have a westward termination (a west ward, but not travelling, surge) at 20-21 MLT. Approximately the same position of this structure was found in DMSP data a t ~ 20.30 UT in our case. According to the referred paper and the all-sky camera data of Cheluskin station for fJov.24, 1981, this structure is very dynamic in its form and brightness, but rarely shows sig nificant spatial shifts as a whole. This distinct feature seems to be a projection of the active outer boundary part of PS, dis cussed in the previous Section. Note, that there is no information on this structure at the plot in Fig.6a, which terminates at 68°A. One more interesting peculiarity seen in Fig.6 concerns the region of the Harang discontinuity. It does not look like a smooth transition region between the eastward and westward jets. We see here a sudden southward shift of the electron precipitation region and rather abrupt appearance of the westward current. Fig.7 presents the equivalent current pattern reconstructed from the data of IMS magnetometer chains (in Canada and Alaska), for the nighttime sector during the first half of the day on Nov.24, 1981. The Harang discontinuity region is a very pronounced feature, but it looks somewhat differently, as compared to Fig.6. Particularly, the orientation of the EC vectors at evening and morning sides is different in these cases which differed mainly by the sign of IMF By-component. Rote, that this pattern was constructed using the data from the stations at different longitudes. Fig.8 (upper part) shows the superimposed (in KLT) X- and Z-coaponent charts of three sta tions (Norman Wells, Tellowknife, Churchill) located on the same invariant latitude but displaced within 3 hours MLT. The trends in the traces at all these stations are the same, showing the ab sence of large-scale changes of the AEJ geometry during this SMC period. This have been checked similarly also for the other lati tudes. At the bottom of this figure, X-components at these stations are given in UT. Strong fluctuations are evident, but there is almost no correspondence between the spikes at these locations (except for the simultaneous changes at ~ C4-.4-5 UT, when presunably a weak substorm event took place). Note, that these fluctuations exist exclusively within both the Earang discontinuity and AEJ^, but not in the eastward AEJ region. Quite a similar pattern of 18