Ионосферные явления-80: материалы наблюдений Поляр. геофиз. ин-та по проекту Междунар. исслед. магнитосферы за 1980г. (оперативно-информационный материал). Апатиты, 1986.

4 IONOSPHERIC РНЙЫОМВНА - ЙО I U S - Observational data of Polar Qeophysic&l Institute USSR Academy of Sciences Editor O.I.Shumilov Apatity, 1986 The volume contains the results of ionospheric observations carried out la . Polar Geophysical Institute and continues the aeries of publications started in 1970 /1/, Since 1977 the data are published in two volumes: Auroral Phenomena /2/ with results of geomagnetic; auroral and balloon observations and Ionospheric Phenomena /3/ with the data of vertical soundings absorption measurements and radar observations. In Murmansk ionospheric sounding is carried out by means of AIS ionosond with frequency range 1-20 Ши, sweep time 30 s, height range 1500 km. Ionograma are take» every 15 min. Information on ionospheric sounding is presented in the form of f-plots with standard designations /6,7/ additionally explained in the Russian text. Absorp­ tion measurements at at.Loparakaya were carried out by means of standard riometer with frequency of 32 MHa, band width of 90 KHe, time integration 30 a, antenna main lobe 50x60° directed towards the Polar Star. The base line is derived from quiet days records monthly» Absorption variation is given on the graph, days with complete absence of abeorption are excluded» Radioaurora observations at at»Easoila were performed by means of radar on f =88 MHz with band width of 270 KHz, power in pulse 60 kw, range of 200 km, the period of antenna rotation 40-90 s. The time of redioaurora occurence is given in Tables, The geographic and corrected geomagnetic coordinates of stations, according to calculations /5/ are; Murmansk: .У 1 =69.0°, Й =33.0°, ф с ■64.5е. Лс *<115.2°, L -»5..5» Loparskaya: «68.3°» Л =33.1°» Фс *>64.0°, Лс =114.8°, L -5.2; Bsaolla: ,':Р »61.8°, -33.3°, Фс =57.5°, Лс = 111 °, Universal time ів usud everywhere. The behaviour of the ionosphere significantly depends on the presence of magneto- spheric disturbances. Their distribution over the year is examined in /4/. In mostly compact form this distribution is presented in the Calendar, l'ig.1. Estimation of activity is givea according to ionospheric, geomagnetic and auroral observations* The growth of activity is denoted by black spots. It is evident that the three types of activity estimations agree rather well,’ though the activity level turns to be slightly different, i.e. disturbances are registered more often from ionospheric indices than from the two other forms. Diurnal variations of activity with the day time minimum (the middle of each line) as well as seasonal variations when the activity level is higher in the second half of the year are seen. The days in the Calendar are ordered according to Bartel's rotation number 2002-2014. The plot in Fig.2 also presents evaluation of activity since it contains t H daily mean (falues. The ІШ? signs (poaitive from the Sum) are also given. The days with increased activity in the magnetograms are marked. The considered year is anomalous in many respects. It takes place at the maximum phase of the solar cycle, but the meen yetr level of geomagnetic activity (on t H data) is the lowest during last 11 years /»’./. Besides the usual seasonal course of activity (with maxima during the equinoxes) is also disturbed. In this year geomagnetic activity has its minimum in March ana maximum in June. In the second half of the year the maximum is reached in October November, i.e. a .little bit later than the expected time. The distortion of the велзоваі course may be