Электродинамические процессы в высоких широтах: материалы междунарордного симпозиума «Полярные геомагнитные явления», 25-31 мая 1986 г., Суздаль, СССР / Междунар. геодез. и геофиз. союз, Междунар. ассоц. геомагнетизма и аэрономии ; Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [редкол.: О. М. Распопов (отв. ред.). и др.]. - Апатиты : Кольский филиал АН СССР, 1988.

JAN.17,1985 6 30.0 г H-COMP. 08 09 10 11 I I ' l I T i l I I 'I ..I I I I I I N 60 30 0 30. 6 0 s HYA I I HSD BJA 08UT 09 10 11 (75.4) (73.5) (71.1) Figure 5b. Left panel: auroral emission intensity (630.0 nm) in UT and zenith angle coordinates. Right panels: H-component magnetograms from the Svalbard station Ну Alesund (HYA), H o m s u a d (HSD) and Bjoraoya (BJA). The zenith angle positions from Ну Alesund of the F-region (300 km) above these stations are indicated in the left panel. geophysical response observed on the ground. I n the period 0745-1000 UT three major changes in the IMP state took place. A strong disturbance occurred at 0745 UT (cf. Fig.6a). The total field was suddenly enhanced by a factor of 3, from 10 to 30 nT, then decreas ing after a few minutes to a stable level of 20 nT. Associated wi t h the change a switch of В from +7 to -17 nT was detected. В changed from -10 to +3 nT J X before returning to nearly the initial value. The next major IMF transition occurred at 0818 UT wh e n B z went positive. B x changed from -6 to +3 nT at the same time. B total and B y did not change. At ~ 0925 UT the IMF vector turned farther northward. The auroral re d line (630.0 nm) intensity versus time and zenith angle is presented i n the middle panel of F i g . 6. B etween 06 and 08 UT the dayside aurora was located close to the southern boundary of the field of view of the photometer system in Longyearbyen, corresponding intime to a large negative IMF B z component (cf.Fig.6a). A factor of 3 increase in intensity occurred just before 0 8 UT, some 15 minutes after the IMF compression was detected outside the bow-shock. A subsequent decay of the red line started at 0800 UT and reached a stable level at 0815 UT. The right p a n e b in Fig.6a show the H-oomponent magnetic deflections at the stations Ну Alesund (HYA), H o m s u n d (HSD) and B j o m o y a (BJA). Hotice the I25