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.

It is especially interesting to study the time interval 03 - 06 UT when the six ted coronas were observed in all sky films. Very strong pulsation in absorption were seen at Kevo and Ivalo and t-he minima of absorption were found at the same time when red aurora were observed indicating that pulsations in the riometer absorption in this case is caused by variation of energy of drifting electrons. The minima are seen at Kevo arid Ivalo at 03.06, 03.28, 03»54* 03.59, 04.20 ( started at 04.08), 04.41 and 04.56 UT.Ab sorption decreased afte 1 05.24 UT. At Sodankyla riometer pulsations are no more Sq clearly seen, but in the cal culated n valuee based оцthe multifrequency riometer mea surements made at Sodou-kyla very strong variations were seen ( Fig. 8 ). 11/12 Dec. (Fig.7by, before 18 UT weak absorption was observed north of Rovajj-iejni. Between 18.00 —18.20 UT ab sorption event was seep- at Ivalo, this event is weak at Kevo. After 20 UT absorption was observed again north of Rovaniemi. A clear incPea/se of absorption was seen at Ivalo at 20.20, 20.49 and 21,O'] UT. At the same time when an un usual event was obs e r v e in all-sky film between 00.10 - 00.30 UT a strong absorption event was found at Oulu. After 01 UT very slowly and ^Qakly Variating absorption was seen north of Oulu and agaia the minimum in absorption was seen at Ivalo and Kevo at 0^»04 when a red aurora was observed in all-sky film. 3 . Data interpretation effld discussion. As was shown above in the morning s ^ t o r of Dec* 1/2 was registered red А-type aurora with the Prevailed 6300 A [Ol] emission af ter 02.30 UT and consequently with the increased value I 6300/1 5577 intensity ratio. Mean value I 63 OO/I 5577 in tensity ratio was eqUaJ- to 3 > 5 and at times reached to 10 and even to 20 in t£s morning sector ( see Fig.10 at 03.55 UT). According to Judge С S] calculations the ratio values observed during this correspond to characteristic^ energies of ^0.3 keV of precipitating^electrons, while E ~ 5 7 10 keV in the nighttime sector ( E=2a). The great 6300 intensity registered a b o u t 10 kR in the morning sector gives rise to assumption of high fluxes relatively soft ele ctrons were at the bot'kcmi of this auroral phenomenon.