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.

Geomagnetic efficiency o fSolar ejection depended on relative orientation o f Sun and Earth rotation axes Novatnbar-Oaeambar-Januarv >k f * * c k ^ •$> <t $ £ Solar sourse latitude February-March-Aprtl Solar sourse latitude £ $ jy fi 4> *> Solar sourse latitude Solar soorse latitude Fig.3. Latitude distribution of geoeffective CME Solar sources on seasons. Auguat-Saptambar-Octobar May-Juna-Jula May-Juna-Jula 1996-1998 May-Juna-Jula aoutxw -43 -M -22 J1 -It ■« -H E S а В I 14 К 18 21 22 2« 42 Solar sourse latitude $ 9 9 <? ^ л* ,sv .» > t * t H Solar sourse latitude Solar sourse latitude Fig-4. Latitude distribution of sources geoeffective CME in summer solstice by phase cycle: rising 1996-1998., maximum 1999-2002 and declining 2002-2006. 3. Conclusions Research of latitude distribution of Solar sources of geoeffective CME for studying of influence of Solar rotation axis inclination on seasonal variation of geomagnetic activity is carried out. It is established, that during periods of autumn and spring equinoxes Solar sources of such streams mainly settle down above/below Solar equator (in zones of royal latitudes), while during the periods of solstice of coordinate have approximately symmetric distribution concerning equator (fig. 3). This effect is more pronounced in years of low Solar activity. Consequently, growth of geomagnetic disturbances during equinox is associated with increased in probability of magnetosphere meeting with plasma stream in these intervals. It occurs owing to change of Solar rotation axis inclination to Sun-Earth line and increasing latitude of Earth helioprojections on the Solar disk. At these moments, the Earth is projected to areas of active Solar areas, ranging between 10 and 30 degrees of northern and southern heliographic latitudes. Acknow ledgements. This work was supported by RFBR grant 12-05-00425 and by the project "Development of modem methods of forecasting the state of the magnetosphere-ionosphere in order to ensure successful communication by finding the fundamental regularities of solar activity" of Ministry of Education and Science. References Barkhatov N. A., Gromova L. I., Levitin A. E. and Revunov S. E. The relation between solar activity and orientation of the solar wind electric field relative to the Earth’s magnetic moment Geomagnetism and Aeronomy, 2008. V. 48. N 6 . P.713. Chapman, S., and J. Bartels // Geomagnetism. Oxford University Press. New York. 1940. №. 11. Cortie A.L. Sunspots and terrestrial magnetic phenomena, 1898-1911: the cause of the annual variation in magnetic disturbances. Monthly Notices of the Royal Astronomical Society. 1912. V.73. P.52. Kuznetsova T.V., Laptukhov A.I., Kuznetsov V.D. Allowance for the geometry of solar wind interaction with the Earth's magnetic field in geoeffective parameters and in the prediction of geomagnetic activity // Solar System Research. 2006. V. 40. N 6 . P.513. Russell C.T., McPherron R.L. Semiannual variation of geomagnetic activity // J. Geophys. Res. 1973. V.78. P.24. 87