Полярные геомагнитные возмущения и связанные с ними явления : материалы международного симпозиума «Полярные геомагнитные явления», 25-31 мая 1986 г., Суздаль / Междунар. геодез. и геофиз. союз, междунар. ассоциация геомагнетизма и аэрономии, АН СССР, КНЦ, ПГИ. – Апатиты : [б. и.], 1989.

V .R .T a g ir o v , V .S .I sm a g ilo v , S .A .C h em ou ss FORMATION OP AURORAL TORCH STRUCTURES Introduction. Torch structures represent a large scale indulatlons of the poleward bound ary of diffuse aurora (Fig.1) /1/. They are usually obser ved in the midnight and morning sectors of the auroral zone w h e n K p 3. The formation of the torches is closely connected with proceeding substorm a c t i vity. They drift w i t h the velocity less than 1 km/sec in the eastern directi on and may exist in some cases for 15-30 m i n (Fig.2, upper panel). Drift m o tion of several torches causes geomagnetic Ps6 pulsations (Fig.2, lower panel). Andre and B au m j o h a n n /2/ were the first to show this on the basis of the data obtained fr o m the Scandinavian magnitometer network, all-sky cameras and STARE radars and proved the model of Gustafsson et al./З/. This model explained Ps6 pulsations by eastward drifting sequence of alternately ch a n g ing upward and downward local field-aligned currents w h i c h cause Hall current circles on the level of the ionosphere. Results of o b s e rvations. T V observations show that the luminosity of the torches m a y be homogeneous and stable in time. However in most cases the torches are divided into two parts: the external one wh i c h represents diffuse band having intensity invariable in time and the internal one containing p u l sating auroral patches unstable i n fo r m in the process of pulsation, super imposed on we a k e r diffuse background (Fig.2, photometer and Fig.3). It was also shown by Oguti /4/. These pulsations look like characteristic streaming of luminosity along the boundary of nonpuls a ting band of the torch never pe n etrating through it. The periods of such pulsations are 5-30 sec. Both inward and outward boundaries of the torch in the case of April 1, 1984 were clear enough to determine the height distribution along them using Fig. 1. Photographs of the torch structures made from DMSP-2 satellite 1. 88