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.

18.15 UT after which the disturbance became negative and lasted until 05 UT. Maximum disturbance was recorded at 21.15 UT (-690 nT) at Loparskaya. During most of the time the centre of electrojet was located near the latitude of Loparskaya,but after 02 UT it shifted significantly poleward. Pig.5b shows variations in the H-component on Dec 11./12. 1977» To study the relationship between red coronas and changes in the magnetic field temporal variations of the electro^et direction (azimuth A 0) and location ( aZ/ дН, or Д2/ дх ) were calculated. These are shown in Pig.6 together with ду, дх- variations at Sodankyla and a sketch of Pig.9a. The joint analysis of all these curves leads to some pre liminary conclusions. All red coronas (or most of them) coin side with the equatorward motion of the electrojet, reahcing of the southernmost position and beginning of reverse motion. During the coronas electrojet azimuth was increased. We can propose that such a change in the current direction is due to intensification of downward field-aligned current with foot point poleward of Sodankyla. There exist also other interpretations. Changes in the energy spectrum of particles will result in change in the Hall and Pedersen conductivities ratio 2^/ £ and hence in the dire ction of total electric current. Riometer data. Dec. 1./2. 1977 (Pig.7a). On December 1. before 18 UT no cosmic noise absorption was observed in the recordings of the Finnish riometer chain. After 18 UT weak absorption was seen at Kevo and an absorption event after 18.16 UT at Ivalo. This absorption event was not observed in any other station. The second absorption event started at 20.28 UT at Rovaniemi, Sodankyla, Ivalo and Kevo. This event was quite weak. A stronger event began at Ivalo and Kevo at 20.52 UT. The beginning of this event was so sharp at Ivalo that the breakup must have occurred quite near Ivalo. Between 21 - 00 UT absorption was observed north of Sodankyla and after 00 UT absorption was seen also at Rovaniemi and later at Oulu too.