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.

lower latitudes ia observed w i t h rising magnetic activity level. At B z=0, for example, the aurora boundary is located at latitudes of 79.7°, 78 . 2“and 74.5° for the Q -index values of 0,3 and 5, respectively. F igure 1A (A) shows the data set for the three events disregarding the differences in the roagnetio activity level. The scatter of points is indica tive of аЪявпсч of a n y relationship between the aurora position and В ("r " = 0 . 11). Th i e value of Mr" is practically coincident wi t h that obtained by Eather et al,(1979). F igure 14 (e) shows tl:e same date, set in the дф' , coordinates- 2№.ч ЛФ1 value was calculated to.be the deviation of the auroral oval equatorward boundary in the particular cases from the boundary of the mean statistical oval at the respective I.T moments and for the respective Q-index value. In other words, the formula obtained by Sterkov (1969) was used to correct the effects of local time and magnetic activity on the auroral position. The pronounced increase of "r" indicates a sufficiently close relationship bet ween the дФ1variations and the IMP В -component ( " r "=0,82). 2» Figure 15 shows the position of the daytime aurora equatorward boundary versus Bz~component in two cases where the magnetic activity varied through out the intervals examined. On December 31,1980 (Fig.15a), despite the spread of points, there exists a distinct relationship between the aurora boundary position and the B g value ("r""0.92) whereas on November 28,1980 (Fig.15b) such a relationship is absent in praotice ("r"»0.25)« From Fig.15(c) it is seen that the transition to the ДФ1 , B 0 coordinates reveals a distinct r elationship between the equatorward boundary position and the B,,-component ("r" * 0.90). Thus, the particular cases presented above (Fig.10 and 11) an d the examination of the statistical relationship of the auroral equatorward boundary to the B z value (F i g . 1A and <5) have shown that the daytime aurore. dynamics in controlled by the IMF B_-oomponent variations. This proves to be especially evident at a lew magnetic activity level. As the magnetic activity increases the entire luminosity band shifts equatorwards, while the IMF-dependent w r i A t i o n a of the auroral position ara observed at lower lati tudes. Similar results were obtained by Vorobjev and Reahenov (1979) who •o 78 76 74 72 Ф' 74 72 З І.І2 .І9 4 0 . a • л I 5 кг'о J— I — u +4 28.I*. 1980. -I— '—1 __L. —4 г=0.Г? '■+» '"8,,nT -J__ I___L +4 АФ 1 r - 0.25 __I__I., +• ®s.i^ Я с *'• > я J __ L a ? ? _j— i_ +» fci.nT Figure 15• The same aa in F i g . 14 but for December 31,1980 (a) and ЯаѵчгаЬег 28,1980 (b). The data eat for the two days in the Дф* В coordinates (с). •40