Электродинамические процессы в высоких широтах: материалы междунарордного симпозиума «Полярные геомагнитные явления», 25-31 мая 1986 г., Суздаль, СССР / Междунар. геодез. и геофиз. союз, Междунар. ассоц. геомагнетизма и аэрономии ; Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [редкол.: О. М. Распопов (отв. ред.). и др.]. - Апатиты : Кольский филиал АН СССР, 1988.

figure 9л The development of the December 30,1984 auroral events inf«jrr*d. from the Heias Is. observation data. Shown from top to bottom are the purora dynamics, the value of the n ratio i n the zenith, and the standard data of a n ionospheric station. positions of the poleward and equatorward boundaries of the 630.0 n m emiss ion luminosity inferred from the scanning photometer data. A Proad region of visual diffuse luminosity was observed during the 0400-0500 UT interval together w i t h homogeneous auroral arcs moving equator- warda. The 557-7 n m emission is the brightest in the auroras wh i c h occured during that interval. Its intensity was several kR. The intensity of the red oxygen line wa s low; the I ^ 0 .0 ^ 5 5 1 . 7 x a i i-a waa <<: 1 * The v e lue oi' ratio at zenith is shown in the middle of the figure and is indicative of the pre cipitating sufficiently hard electrons. The ionospheric data presented in the bot t o m of the figure indicate the existence of blBckout during that period. The rayed auroral arcs moving polewards appeared at about 0500 UT near the station zenith. The arcs ware observed until 0900 UT, i.e. within the 0900-1300 MLT interval. As soon as the arcs moving polewards appeared the spectral characteristics of auroras changed substantially. The 630.0 nm I33