Physics of auroral phenomena : proceedings of the 40th annual seminar, Apatity, 13-17 March, 2017 / [ed. board: N. V. Semenova, A. G. Yahnin]. - Апатиты : Издательство Кольского научного центра РАН, 2017. - 143 с. : ил., табл.

high speed streams from coronal holes (HSS), magnetic clouds (MC) and plasma compression regions in front o f these structures (CIR and Sheath) according to [16], [17], [14], [18] and based on the catalog of large-scale solar wind phenomena {ftp://ftp.iki.rssi.ru/omni/) . Auroral geomagnetic disturbances were verified by the ground-based data of IMAGE magnetometers network (using the meridional TAR-NAL and MEK-NOR chains and by data of Loparskaya (CGM lat. =65.43°) and Lovozcro (CGM lat. = 64.23°) magnetometers. LT values for IMAGE network stations are LT ~ UT + 1 + 2 , MLT values for IMAGE network are MLT ~ UT + 2 + 3, for Apatity’s MAIN cameras MLT ~ UT + 3.17 (~ 3 horn's and 10 minutes). b) Substorm identification For the substorms selection, we used data of magnetometers and data of all-sky camera. First the presence o f a substorm was identified by the IMAGE magnetograms, then the substorm onset at the Apatity’s latitude was determined by Sodankyla station (SOD) magnetograms and, if observations in this period were available, additionally, by Loparskaya or Lovozero stations magnetograms. After that we determined the substorm by the data o f the MAIN cameras system in Apatity during clear sky measurements. We divided the auroras according to their appearance into 3 groups: to the South from Apatity, to the North from it and near the station zenith, i.e. near the Apatity location (from 0° to ~ ±50° from zenith). It should be emphasized that with these criteria for selecting events, not only isolated substorms are included in the review, but also different intensifications of one substorm. During the examined winter seasons, the all-sky camera registered more than 180 substorms and their intensifications. c) Observation conditions First, we divided the conditions of observations into 2 groups: storms (when the minimal SYM/H value SYM/Hmin<- 50 nT) and non-storm periods. Second, we divided the observations conditions into sub-groups appropriately to these phases of the storm: initial, main and recovery phases, in the recovery phase also near and late recovery phase were defined. We considered also the events with “structured recovery phase”, if after the first, deepest SYM/H minimum, other sizable SYM/H minima were observed. The recovery phase was assumed as structured, if there were SYM/H fluctuations, meeting the condition (SYM/Hflmm- S YM/Hflmax)/SYM/Hram>0 .5, where the SYM/Hflmm is the minimal value reached during the fluctuation and SYM/Hflmm - SYM/H ятах represents the amplitude o f the fluctuation. The non-storm conditions were classified in two sub-groups regarding the presence of solar wind structures. The first sub­ group included events under quiet conditions, when no structures in the solar wind were observed, and the second sub-group included conditions when structures in the solar wind near Earth were present, but these structures did not causc geomagnetic storms. Results In this work we studied the substorms development in Apatity during different space weather conditions. AE and SYM/H geomagnetic indices are the indicators o f the geomagnetic activity. We presented here the analysis the location o f the onset o f auroras depending on the values of AE and SYM/H indices for the different observation conditions (according to the paragraph “c” from the section "data"). It should be noted that we have not found significant differences between the different groups of auroras onset during different observations conditions depending on AE index (this picture is not presented here). The results for the dependence o f the aurora locations on the SYM/H index values for the different groups o f space weather conditions are presented in Figs. 1, 2 divided into 3 groups according to the location o f the initial auroras: to the South from the Apatity location (S), to the North from it (N) and near the station zenith (Z). In Fig. 1 the dependence of the substorm aurora appearance in Apatity (called further aurora onset over Apatity) on SYM/H index during the initial (blue diamonds) and main (red squares) storm phases is presented. It is seen that at the onset of the geomagnetic storms, during the initial phase, regardless of the higher (often even positive) SYM/H values auroras may originate to the North as well as to the South from Apatity (the blue diamonds in Fig. 1). The black vertical line indicates the boundary between observations of auroras in the South part and in the North part of all-sky camera images. It is seen that at SYM/H values lower from about -45 nT auroras occurred to the South from the station zenith. Observations o fsubstorms in Apatity by MAIN cameras system during different space weather conditions SYM/H, nT Figure 1. Dependence o f the onset location of aurora on SYM/H index. Blue diamonds indicate the events during the initial phase, and red squares - the events during the main phase of the storm. 12