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.

about 10 minutes before the sharp activation that began in the quiet arc in the south at 20.28:23 UT. Three minu tes earlier the arc had got a double structure. The main activity travelled from east and developed into a loop- like auroral structures (WTS) that slowly propagated over Muonio. The recovery phase with diffuse pulsating patches was observed to start at 20.45. The movement of auroral forms changed from westward to eastward at about 22.00 UT. At 00.01 and 00.23 large eastward drifting wavy structures passed the meridian of Muonio. Red auroras were seen in the late morning hours. The first green—red corona appeared at 03*01...03*10 at Muonio. Second small corona at 3*^5-3*30, and third weak corona at 3*55-3*57* At 4.00 red rayed bands travelled from west and formed corona at 4.05-4.09. After a temporary fading of the aurora in the north-zenith region a large colourful and bright red corona formed at 4.35-4.42. In this corona we could distinguish also violet and blue colours on the all-sky film. The last corona appeared at 5*30-5*39 Fig*2* Pulsating patches and bands appeared between the coronas. Sometimes rayed bands were seen to move eastwards at the average speed of 50 km/min (30-70 km/min observed). Red coronas are not usually observed in the morning sec tor of the auroral oval. Diffuse surfaces and patches,that often pulsate, are typical auroras of this time sector. The structure of the red auroras in the morning of Dec. 2 1977 resembles much the aurora seen in the dayside oval. Accor ding to [2] the dayside auroras have weak intensity, short lived ray structure (duration ~10 min), and their equatorial boundary is determined by substorm intensity. The rayed structures move typically polewards. The red aurora that we recorded had similar features: short-lived rays with bright ness not exceeding IBC 2. Poleward shifts were not observed but for coronas it is always difficult to recognize move ments. Eastward propagation was detected in some cases and seemed to be 2-4 minute delays in the appearance of coronas at the Finnish and Soviet stations.