Авроральные явления 70-II : материалы наблюдений Полярного геофизического института за второе полугодие 1970 г. / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [отв. ред. Б. Е. Брюнелли]. - Апатиты : Кольский филиал АН СССР, 1974.

5 two phenomena are connected by linear dependence. There exists a good correlation between three manifestations of auroral activity (magnetic, ionospheric and auroral). So to describe the general behavior of activity during a second half year of 19?0 the magnetic activity was chosen. Short time increasings of the activity according to the calendar are as rule connected to the solitary bay—type disturbances which amplitudes ban be rather high. As the activity increases the successions of the bays appear (instead of the separate events). Under weak and moderate conditions in the evening the positive bay is observed, then later the disturbance is absent and near midnight the negative bay develops. The activity increases, the undisturbed interval becames shorter and at last the negative bay is observed immediately after positive one. The translation point is observed earlier as the activity increases. There often exist the reccurence of disturbances during successive days. The example of such a succession from 25 to 29th Of August is shown in Fig.7. The most disturbed month July is characterized by rather numerous cases of sudden commencements (SC). When SC takes place during night hours, the negative bay develops immediately after SC. The occurences of some SC-s are.rather alike (3,9 and 25th of July). During these days SC events were observed at recovery phase of rather small negative bays (Fig.b,9,10). The recovery phase finished at moments of SC and values of new bays were higher then that of the former ones. If SC was observed in the morning the reaction of magnetic field was nearly absent, except pulsations sometimes appeared. A rather low activity occured during the first week of August, but the separate bays were observed (August 6 and 12). The intense magnetic storm began after SC at 2204UT. This storm consisted of the series of superimposed bays (negative and positive). The polar cap absorption event was observed during 10-1?th of August. The next succession of substorms was observed during 25-28th of August. The world-wide storm with gradual commencement began on the 1 3 th of September. During this storm intense absorption was often observed generally in the morning. During the night a good coincidence of times of maxima both absorption and auroral activity was observed though the ratio of their amplitudes demonstrated a great changeability. The next storm consisting of the some negative bays was observed from 19 to 21st of September (Fig.12). The dynamics of aurora and magnetic field variations was considered during the moderate disturbance on the 25th of September. On the 1-3rd of October aurora were also observed when magnetic field activity was nearly absent. In the evening before the onset of the negative disturbance aurora were observed near the northern horizon of Loparskaya on the 1 st of October. The first auroral substorm was observed at moment of negative burst of S>H which occured in the course of the positive bay. The next outburst of aurora was observed during decreasing of gH but the value of & H was still positive ( 5" H> 0) . The break-up occured after outbursts of aurora. During this phase the most of auroral intensity was concentrated in regions of background glow. During the recovery phase of auroral substorm the background auroral glow collapsed in the direction of the northern horizon. On the 1-2nd of October after 2300UT a rather intense magnetic bay was observed. The bay was accompanied by absorption. On the 2-3rd of October the amplitude of magnetic field variation was less than 60^". But inspite of this the small auroral disturbances developed according to the general scheme of auroral substorm without noticeable changes of magnetic field intensity. The results obtained were illustrated by synoptical maps of aurora. The dynamics of aurora during the series of small negative bays was investigated in detailes. The amplitude of the first bay was equal to 500f. The course of integral auroral intensity was in general like that of magnetic disturbance exept in so far as in series of bursts during activation phase of substorm which coincided with sharp increasings of dumping rate of J h , On the 16th of October the world-wide storm began at 0918UT (SC). Before the