Авроральные явления - 80 : результаты работ по программе Международного года исследований магнитосферы : материалы наблюдений Полярного геофизического института за 1980 г. : (оперативно-информационный материал) / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [отв. ред. Б. Е. Брюнелли].

6 to the positive aector in the second half of the year. The first statement is poorly manifested in the given data. The reversal of the sign occurs much more frequently on the greater part of 'rotations than it is possible for active periods. The sign changes from 10 to 20 times per rotation; the number of active periods осcuring during one period must be, as a rule, much less* Most of the changes of the IMF sign are not accompanied by active periods. She second statement is confirmed much more distinctly. Figure 7 presents the comparison of aotivity levels calculated separately for days with the positive and negative IMF signs for every month. Exceeding activity in the negative sector during the first half of the year is reraarkably seen. The effect of the sector's sign on the activity can be easily observed while considering separate magnetic storms (this lias been carried out in the Russian text). It can be demonstrated that magnetig storms occuring in the increasing sector are characterized by longer duration, numerous substorms and their higher activity. The analysis of field responses to sudden commencements registrated at Loparskaya and cited elsewhere /13—15/ shows that Sc appearence during morning and day hours causes only intensive pulsations on the records. Sc at 3.10 UT on 19S0.02.14 may be taken as an example. Sudden commencements that are preceded by remarkable activity in the auroral zone, as a rule, cause intensive substorms, i.e. are registrated on the magnetograms at Loparskaya in the form of sharp substorms, SC at 21.38 UT on 1980.05.31 may serve aa an example. Geomagnetic observations at Loparskaya station were carried out by V.Ya.Gorelov, spectral observations were carried out by L.S.Yevlashin, G.,V«Starkov, and G.F.Totunova, the analysis and text compilation was made by B.E.Brunelli. The issue was prepared for publication by L.V.Kovalevekaya and V»A ,Sakharova.