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.

high latitude of the sporadic auroras and emission maxima to the interval 0559 to 0603 UT. In fig.8 the position of all observed 6300 A intensity m a x i ma ha3 been plotted as a function of time independently of their magnitude, assuming a height of 300 km. The position of the megnatic meridian through Godhavn-Sondre Stromfjerd of visual auroras observed by the all-aky cameras has been plotted assuming a height of 110 km. Relevant satellite observations of positions of poleward, transition and equatorial electron precipitation boundaries have been included in the figure. Notice that the satellite orbits at 0421 and 0602 UT are situated at magnetic local time 2.5 - 3 hours later than the contemporary ground-baaed observations. Due to the curvature of the precipitation boundaries toward higher latitude at later magnetic time, the latitudes of these equatorial and transition boundaries should be reduced by 1°-2° for direct comparison with the ground-based observations. This has not been done in Fig.8. The ground-baaed observations confirm the equatorward movement of the outer boundary beginning after the first substorm onset. The photometer measurements indicate a thinning of the number of sporadic intensity increases beginning from north ab.0520-0530, i.e. 10-20 minutes after 6 -incr ease and 40-50 minutes before the aubatorm onset. Incoherent Scatter RAdar observations, alao shown in Fig.8, of the poaition of the convection reversal, indicate a rapid southward shift of the reversal from 0550 to 0602 UT. Although the position of the reversal in relation to the precipitation bound aries is not well known, the observation seems to support the conclusion that the poleward boundary is moving rapidly toward equator 15-20 minutes before the first substorm onset. Fig.: 9 electron precipitation profiles along the dawn-dusk meridian for the two consecutive dawn-duak northern hemisphere crossings beginning at 0421 and 0602 UT, respectively. MLT 609 611 6(4 620 636 Ш 1752 1805 йй (814 MLAT 56.0 62.8 69.8 76.7 6Ш Ш «2.1 75.0 67.8 60.7 CLAT 58.7 65-0 712 76.6 008 80.6 76.6 71.1 65.1 583 T -T;"'-*)'....Г ; W О Щ UJ cb ss UJШ § cb Fig.9. Electron precipit ation data obtained by DMSP- aatellite number 7540 on Nov.29,1984 at 0421 to 0441 and 0602 to 0622 UT. Black triangle in timescale at 0612 UT indicates onset of substorm. 04UT 2343 2543 2743 29© Ш 3359 35533759 39594159 TIME IN MNSC MLT 652 655 659 708 743 1600 (856 1844 /848 1850 IILAT 579 .05.2 72 2 79.3 863 86.1 79.0 71.7 64.5 57.5 , CLAT 575 63.6 70.0 75.7 8 0.1 81.0 777 72.5 66£ 60.5 ................................................ il M 7173 78 Cb z:Ш % 06UT 4(1 6(1 811 (0(1 1212 № (612 (8122012 22(2 TIME IN MNSC 112