Авроральные явления - 81 : материалы наблюдений Полярного геофизического института : (оперативно-информационный материал) / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [редкол.: О. И. Шумилов (отв. ред.) и др.]. - Апатиты : Кольский филиал АН СССР, 1988.

5 broadening of the maximum in winter with increasing of darkness of the day ie clearly seen. Comparison of daily mean values of hourly range rH with sector signs of IMP is carried out in Figure 5. Figure 6 presents the 27 days plots of Dst variation averaged for 4 hours intervals together with the sector signs changes. The tendency for formation of recurrent sequencies is proved to be poorly manifested. The regions of increased activity in both figures are shifted mostly towards more later days; the recurrency, if any, is realized in more than 27 days. At least Figure 7 presents the connection between the level of geomagnetic activity and the signs of sector structure of IMF. One can see that during the first half of the year the most disturbances there appeared during positive IMF sector and then both sectors (negative and positive) were equally connected to the mean values of rH parameter. In general (see the Russian text) the connection with the changes of the sign of the X component of IMF and the level of geomagnetic activity did not appear to be well pronounced. It is better to study such tendency when using the Z and Y components of IMF instead. Geomagnetic observations at Loparskaya station were carried by N.N.Volkov and L.I.Sergeeva. Spectral and auroral observations were carried out by G.F.Totunova; auroral observations were done by V.L.Zverev and G.V.Starkov; the analysis and text compilation was prepared by O.I.Shumilov. The issue was prepared for publication by L.V.Kovalevskaya and V.A.Sakharova.