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.

6 a term waa relatively quiet period. Immediately after SC pulsations appeared and at 1100UT the positive disturbance turned into negative one. On the next day early development of positive and negative intense disturbances was also observed similar to previous day (Fig.22). The next moderate substorms were observed during October 22-24 and 27-29. These disturbances consisted of the series of bays. The successive disturbances being connected to polar absorption appeared during November 4— 9. After SC the 3 torm began on the 1 bth of November. The SC occured in the afternoon so the positive disturbance consisting of four substorras began in two hours. During night hours the intense negative disturbance occured. This disturbance continued up to the morning.The last burst was already positive at 07 0 0 UT (Fig.25). The next storm with SC began on the 21st of November. The SC occured in the morning so the disturbance was a positive bay which began in four hours after SC moment. The period from 2 9 th of November to 1st of December was quiet. During December 4-7 the moderate disturbances was observed. Then also the quiet period was observed. The world-wide storm with SC occured during December 14-15. The next period up to the end of 1970 was relatively quiet. The series of moderate disturbances connected with two SC was observed during December 27-30. II. The original works I.Osepjan A.P. Sudden commencement absorption at time of geomagnetic storms. The peculiarities of SCA during intense geomagnetic storms In 1970 are investigated. It is shown that appearance of SCA dependens on the previous level of disturbance and does not depend on the type of geomagnetic SCA (by Matsushita). The interpretation is given in terms of Kennel-Petchek diffusion theory. 2.Petrova G.A. The polar cap absorption events (PCA) in the second half year of 1970« Two cases of PCA on the 15-17th of August and 6-9th of November are described in details. The attention was paid to the effect of noon recovery and superpoeition of the auroral and PCA phenomena in the course of the geomagnetic substorm. 3.Afanasjeva L.T., Selivanov V.P. The geomagnetic pulsations. The ststiatical analysis of all. the types of geomagnetic pulsations is done on Lovoze.ro earth currents data in 1970.. The diurnal and seasonal variations are obtained for both frequency occurence and mean periods. The dependence of mean periods of all the types on kp values are also investigated. The characteristic examples of more interesting cases of Pi2 and Pel pulsations events are shown. 4.Afanasdeva L . T . , Osepjan A.P. Long period pulsations of geomagnetic field and absorption. The coincidence of Pc5 pulsations and AA was investigated during 1970 (magnetic data - Loparskaya, Lovozero, absorption - Loparskaya). The occurence of pulsations of auroral absorption turn to be depending on the intensity of corresponding geomagnetic bay with Pc5 pulsations superimposed. 5. Sbulgina N.V. The sporadic forms in F-region. The investigation of diffuse есЬоз from F-region on f-plot data of 1970 of Murmansk ionospheric station was done. Only events when several, sporadic layers existed were took into account. The seasonal and diurnal variations of FS'layer parameters were analysed. 6 .Shulgina N.V. Diffuse echos from F-layer. The morphological peculiarities of the diffuse echos from F-regions are descri bed. Some examples are shown. All the cases of the diffuse echos during 1970 are lis ted. The diurnal and seasonal Variations are investigated. It is shown that the dis tinct diffusion pictires take place near local midnight. The weak d f f u s i o n pictures take place in the evening and in the morning. The probability of the appearance of the diffuse echos in winter is increased by a factor of 3~5 of that in summer. 7.Sukhorukova E.V. The moments of the increased ionization in the auroral zone. The peculiar type of ionospheric disturbance characterised b y a sharp change of ionization in E~ and F-regions under the high solar zenith angles is described. All the oasee of this phenomenon in winter 1970 are listed.