Physics of auroral phenomena : proceedings of the 39th annual seminar, Apatity, 29 February-4 March, 2016 / [ed. board: N. V. Semenova, A. G. Yahnin]. - Апатиты : Издательство Кольского научного центра РАН, 2016. - 167 с. : ил., табл.

Comparison o f the "expanded" and "polar" substonns behavior during the 23 and 24 solar cycles the latitudes. Namely, substorms start and development at high-latitudes from 71 to 75 degrees of the geomagnetic latitudes. Below these latitudes, the disturbances are absent. It is known that the 23-th and 24-th solar cycles significantly differ in their characteristics and ground eflects. And we can assume that they may occur also in the substorm behavior during these periods. In our study, we analyzed the magnetic substorm occurrence during 23-th and 24-th solar cycles. Data To study the latitudinal substorm dynamics, i.e. the westward electrojet, we used the magnetic data of the IMAGE magnetometers chain Nurmijarvi - Ny Alesund, so, from 57 to 75 degrees of the geomagnetic latitudes. The solar wind and Interplanetary Magnetic Field (IMF) parameters measured by Wind spacecraft were taken from OMNI database. The 1995-1996, 1999-2000, 2008-2009 and 2012-2013 time intervals, close to two different maximums and minimums of the solar activity are used. There were analyzed above 800 events o f "expanded" and "polar" substorms in the listed above years. Results We calculated the seasonal variations of substorms, observed in 4 different time periods - in 1995-1996, 1999-2000, 2008-2009 and 2012-2013 years. Fig. 1 presents the results of two different types o f substorms study: P- “polar” substorms (green lines); E- “expanded” substorms (red lines). a) v ! \ . i \ - i У / 1 4 / ■ l / V{ is y \ / ,\ i b) \ i k' i ' * \ I ?v П I \ I \ ' f V A i \ \A. >\ \ I \ v 1 ; \ r \ ! \ j \ 1 9 4 « 13 I t li* 14 УяЛ с) d) Figure 1. The normalized to the total substorms number distribution of the substorm number by month for “polar” and “expanded” substorms in: a) 1995-1996; b) 2008-2009; c) 1999-2000; d) 2012-2013 years.