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.

СE < 1 keV) flux increased there also occurred hard electron ( E > 4 0 keV) energy softening. The last is in coincidence with the absence of short period auroral pulsations which are assumed to be caused by ~30 keV electrons precipitating from the trapped radiation region of the magnetosphere [ 10] . In the lower half of Fig.8 the parameters are shown for Dec. 11/12, 1977 similar to those discussed above for Dec. 1/2 1977. As it is seen the intensity ratio I 6300/1 5577 stays below 1 during the whole night however in the late mor ning hours ( around 05 UT) the ratio becomes>1 in the nor thern part of the sky. The relationship A / f T shows rising hardness of keV~range electrons between 02 - 05 UT. Small values of the frequency coefficient indicate the intensification of hard electron precipitation ( Б>40 keV) after 04.00 UT. This is in coin cidence with the presence of strong auroral pulsations as it may be seen from Fig.4. These types of changes in the energy spectra on Dec. 11/12 are typical for momingside auroras. On this basis we can make an assumption about the inde pendent source region and precipitation mechanism for very aoft electron precipitation which was registered on Dec.11/12 in the northern sky (A>68°; 07 LT), The similar assumption can be made about soft morning- side precipitation on Dec. 1/2 1977» Thus there are actually no qualitative differences bet ween the two nights, the main differences are more quanti tative both in strength and spatial distribution. This is well demonstrated in Fig.9 A and 9 B. In Fig.9 A and 9 Вthe time latitude ( geographic) diagrams of scanning photome ter data, magnetic H-component disturbances at Kola Penin sula chain and riometer data are given . The photometer lata are recorded at Sodankyla with a N-S scanning photome- О ( 1 scan/min. narrow width 5577 A filter). The intensity i-i given in arbitrary linear scale. Night Dec. 11/12. was i.ostly cloudy at Sodaiikyla which means that numerical compa r i s o n between the two nighte is not fair. Prom the figures