Physics of auroral phenomena : proceedings of the 35th Annual seminar, Apatity, 28 Februaru – 02 March, 2012 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2012. - 187 с. : ил., табл.

N.A. Barkhatov et al. There is also representation about a direct connection between this activity and relative orientation of electric field vector E of Solar wind and geomagnetic moment vector M [Kuznetsova et al, 2006 and references in it]. However, as the electric field contains Bz component of IMF vector, it is possible that the relationship geomagnetic Kp index with the angle between M and E vectors is due simply dependent cosine of this angle of IMF Bz component in the Solar-magnetospheric coordinate system. In this connection, in work [Barkhatov et. al., 2008] the estimate Kp index and electric field and the Solar wind with projection of this field on the geomagnetic dipole has been executed. Here method for calculating Solar wind electric field, showing its greatest geoeffectivenes in form of correlation with an index of global geomagnetic activity Kp is developed. Another cause of the greater number of magnetic storms and storms with strong intensity during spring and autumn equinoxes than in other months of the year may be seasonal dynamics of the coronal mass ejections (CME) parameters, type of magnetic clouds reach the Earth magnetosphere. Due to the fact that during the year changes in inclination of Solar rotation axis relative to Sun-Earth line, the interaction probability of the Earth with ejections from the royal zones increases during the equinoxes. Also in connection with passage of the Earth is closer to CME axis, which is observed strongest magnetic field is responsible for the intensity of the magnetic disturbances, and increases the probability of generating more intense geomagnetic storms. 2. Analysis o f distribution o f solar latitude sources geoeffective CME In this work influence of inclination of Solar rotation axis to Sun-Earth line on seasonal variation of geomagnetic activity on catalogues materials of Solar flashes, CME (http://www.ngdc.noaa.gov/stp/SOLAR7ftpsolarflares.html; daw.gsfc.nasa.gov/CME_list/index.html) and by data about global geomagnetic activity on basis of Dst-index for full 23 Solar cycle (1996-2006) is investigate. Also distribution of latitudinal coordinates of Solar source of geoeffective CME registered in specified time interval is executed. The resulting distribution has two symmetric maximum in zones of royal latitudes ± 10-30° (fig. 2), that indicating preferential location of Solar sources of geoeffective ejections in this range. Solar sourse latitude Fig.2. Latitude distribution of geoeffective CME Solar sources for Solar cycle 23. As noted in the Introduction, change of Solar rotation axis angle leads to change of latitude Earth helioprojection. During equinox it gets in the royal latitudes in northern (the autumnal equinox), or in southern hemisphere (spring equinox). It can lead to increase in magnetic storms number in the given intervals. Division of analyzed data on solstice seasons (November-December-January and May-June-July) and equinoxes (February- March-April and August-September-October) showed presence of displacement of maximum in distribution of geoeffective CME latitude during the equinox periods (fig. 3). During periods of solstice Earth helioprojection latitude gets to area of Solar equator. Thereof CME from northern and southern hemispheres of the Sun are registered on the Earth in equal quantity (fig. 3). This regularity in analyzed 23 solar activity cycles is observed only for the period of a winter solstice (November-December-January). During summer solstice shift of latitudes in Sun northern hemisphere is observed. To study characteristics of shift of geoeffective CME Solar source latitude during summer solstice analyzed data were divided in three parts: the rising phase of the cycle 1996-1998, maximum phase 1999-2002 and declining phase 2003-2006 (Fig. 4). The resulting distribution of Solar source latitude revealed that this shift occurs at maximum phase and declining phase of Solar activity, i.e. during periods of high solar activity. Consequently, such shift may be associated with complex distribution of Solar sources in these intervals. 86