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.

some activity in the early evening hours developiag into auroral breakup close to the magnetic midnight, pulsating pa- tcnes in the morning hours, and decreasing auroral activity towards dawn. As mentioned above, both nights belong to active periods well separated from each other by the quiet period from Dec.6. to 10. During both nights auroral activities lasted from dawn to dusk as observed by optical instruments at Kevo, Ivalo, Mu- onio, Sodankyla, Oulu (Finland) and Loparskaya (Murmansk region, USSR). Even if the activities during the two nights under con sideration are quite different there are also some similari ties. During both nights auroral breakups occur around 20.30. UT,close to magnetic midnight. The locations, intensities and structures of the breakups are almost similar. The main differs ences appear on the morningside: Dec. 11/12. has pulsating pat ches with decreasing intensity towards dawn and only one red corona after 05*00 UT, while Dec. 1./2. has increasing acti vity towards dawn with six red coronas observed between 03*00 and 05.30 UT. Between the coronas typical but weak morning- side pulsating patches wex'e seen on the all-sky films. For this study we collected data from several networks that are in operation in the Scandinavian-Kola Peninsula re gion. All-sky cameras, photometers and spectrometers produced the primary data of this study. Data from the north-south ri- ometer chain operated in Finland reveal the structure of high energy electron precipitation and the corresponding auroral absorption, and the north-south magnetic data give a clue to estimate the location and strength of the polar electrojet during the auroral phenomena. Observations. The locations and instrumentations of the va rious observing sites are given in Fig. 1. All-sky film data. On Dec. 1/2. the recording began at 18.43 UT at Muonio, which was meteorologically the best site during this night. Before 20.00 UT weak westward moving bands were seen in the north and faint bands in the zenith. Around 20 UT a quiet homogeneous arc appeared at 50° above the southern ho rizon (Ф^б?0 N),while in the northern sky there were rather faint active forms by this time. The sky in zenith cleared