Магнитосферные возмущения и результаты измерений в стратосфере за период проведения эксперимента «Самбо-79»/ Л. Л. Лазутин, В. А. Жавков, Т. А. Козелова [и др.]; Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т и др. – Препринт ПГИ 80-1.

electrons were measured, simulteneously on both balloons. Prom 0400 to 1000 UT morning and day baylike intensifica tions of X-ray fluxes and the electric field disturbances were registered onboard the balloon 25 МЕР (Pig.12,13*14). Prom 1930 to 2230 UT the events were the following. The substorm of the period was one of the last at the end of a prolonged activity observed during the previous day (see Pig.2). Aurora films taken by the all-sky cameras at Kevo and Ivalo which were kindly given to us by fi.Piilinen show the development of the activity, though restricted to the longitudinal sector. At 1930 UT a weak activity was observed with insignific ant arcs and patches. The electrojet intensity gradually enhanced. The first breakup appeared at 1950 UT. The patch southward from Ivalo turned into an arc and then at 1952 UT an auroral band appeared over the zenith at Ivalo. It broke into corona with subsequent decay at 1957 UT. After that the activity decreased. At 2020 UT the activity began to increase. Weak diffuse arcs shifting southward appeared. The westward electrojet intensity increased. Gradual growth of the activity continued until 2036 UT. At 2035 UT an auroral breakup was observed in the zenith over Ivalo.This breakup was also marked in all the UI*P-records as Pi2 train development. Decay of the northern arc occurred and the aurora expanded northward. At the end of this short activi- zation at 2042 UT an arc directed west-easx was observed to the south of Ivalo aa well as a bright band directed north- south to the east. At this time the activity on the east intensified and the magnetic field disturbance rapidly in creased at M.Karmakuly, Belyi island. The maximum of the disturbance occurred at 2047 UT. The activity expanded west- weird; the aurora oriented north-south were observed at Kevo and Ivalo. Between 2050 ana 2057 UT the aurora bands on the eastern edge of the sky grew brighter and from 2059 to 2102 UT an auroral surge crossed the vicinity from east to west; the aurora extended throughout the firmament. This broaden ing of the activity was accompanied by strong D disturbance 35