Координированные наблюдения авроральных явлений 1-2 декабря и 11-12 декабря 1977 г. на Кольском полуострове и в Финляндии / С. А. Черноус, Н. И. Федорова, Г. А. Логинов и др. ; Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т. – Препр. ПГИ-79-3. - Апатиты : [б. и.], 1979.

the late morning sector at about 04.00 UT it increases to 10 4 JO ( see Fig.10). At the same time the intensity of 4278 I NG is strongly increased against the green line ( see Fig.4). In this connection it has to be mentioned that one should be very careful if energy spectrum calculations of precipitating electrons are made by using the spectral ratios including 4278 I NG N^. During the second night Dec. 11./12. 1977 the ratio I 6300/1 5577 was below about 0.3 ( see Fig.8) ■until 05.00 UT,when the red corona appeared and the ratio increased to 1 4-4. During the both nights H emission was very low £ 0.4 кR. In Fig.4 the appearance of auroral pulsations in the pe riod range between 1 and 20 seconds are given. According to the figure pulsations in the morning of Dec, 2 are absent in this period range even if we can see some longer period pul sations on the all-sky films ( speed 3 frames/min). In the morning of Dec. 12. strong pulsations are observed which can be expected from typical auroral behaviour in the morning sec tor. Magnetic data. Magnetic data at Northern Finland were ob tained by H.Maurei*, Technical University of Braunschweig. First magnetic disturbance on Dec. 1/2. 1977 began near 16 UT with a weak PiB burst (15*56 - 16.04 UT). The initial phase of disturbance lasted to 20.24 UT when a Pi2 burst (break-up) was observed. Negative magnetic disturbance con tinued to about 06 UT with maximum value in Loparskaya at 04 UT (-816 nT). The development of magnetic disturbance is shown in Fig.5a, where the temporal variations of disturbed H-component along two longitudinal chains are presented. Mag netic disturbance was divided into several active periods* 21.00 - 21.20; 22.00 - 22.30; 23.50 - 00.10; 00.20 - 02.40 UT. The highest activity was observed from 02.50 to 04.20 UT. The centre of westward electrojet was located polewards Loparskaya during this magnetic disturbance. Magnetic disturbance on Dec. 11./12. 1977 began at 20.26 UT on Dec. 10 with a weak Pi2 burst. More active phase began near 10 UT on Dec. 11. Eastward electrojet was observed before