Авроральные явления - 81 : материалы наблюдений Полярного геофизического института : (оперативно-информационный материал) / Акад. наук СССР, Кол. фил. им. С. М. Кирова, Поляр. геофиз. ин-т ; [редкол.: О. И. Шумилов (отв. ред.) и др.]. - Апатиты : Кольский филиал АН СССР, 1988.

4 AURORAL PHENOMENA - 1981 OBSERVATIONS!!, d a t a o p p o l a r g e o p h y s i c a l i n s t i t u t e USSR ACADEMY OP SCIENCES Editor O.I.Shumilov The volume contains the results of geophysical observations carried out at the stations of Polar Geophysical Institute located on Kola peninsula during 1981. The issue continues the series of publications started in 1970 1-12 . Since 1977 the data are published in two series: "Auroral phenomena" containing geomagnetic, optical and sometimes balloon data and "Ionospheric phenomena" 18-21 presenting f-plots and riometer data. This issue includes magnetograms, ascaplots, tables of hourly range rH and tables of spectral intensity inferred from the observations carried out at Loparskaya station. In some cases magnetograms from Loparskaya are substituted by magnetograms from Lovozero and this is marked by an additional scale arrow. Spectral intensity was estimated in 8 ball system for emissions =427,8; 557,74 630,0 and 656,3 nm: conditions of observations are also marked (A stands for good transparence, whereas В and С denote partial and full cloudiness, respectively). The universal time is used everywhere, the local midnight is marked in some events. The Sun passes the Loparskaya geomagnetic meridian at 9.01 UT in the equinox, it occurs at 9#19 and 20.43 UT in summer and at 8.43 and 20.19 UT in winter solstices, respectively. The local midnight falls at 21.53 UT. The studied year is close to the beginning of the XXIst Solar Cycle and is a year of rather high solar activity: the number of sunspots, as well as the value of the radioemissions flux (denoted in Figure 1) are near their тятНтптvalues. In contrast to Solar activity, which only began to fall, the magnetic activity just began to rise as seen from monthly and annually averaged values of the geomagnetic hourly range rH (Loparskaya observatory) given in Figure 1. The same Figure contains also monthly averaged values of the solar radioemission flux density. These values change significantly throuthout the year, the most sharp changes occured during the three last years including the present one. The calendar in Figure 2 contains evaluation of activity for every hour of the year. Diurnal variation with decreasing activity in the daytime (middle of every row) and its every high level during the first half of the year ate clearly distinguished. The tendency for recurrent sequencies is manifested as weakly as in the previous years. The seasonal variations of all activities is presented in Figure 3. It is seen that r^ gains its maxima in April and October and minima in January, June, September and December. It is seen that nearly all monthly rH values in the middle are close to those averaged for 11 years. The diurnal variation of activity from geomagnetic, ionospheric and optical observations for every season of the year is presented in Figure 4. The growth of activity towards night during all the seasons, as well as