Physics of auroral phenomena : proceedings of the 33rd Annual seminar, Apatity, 02 - 05 March, 2010 / [ed.: A.G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2011. - 206 с. : ил.

Solar wind recurrent phenomena in 23-th minimum Days, 11-15 February, 2007,12(-/+) G2 D ays,10-15 M arch,2007,11(-/+) G1 Fig. 1 The CIR area near HPL is typically shown by sharp descending of FD value, a sign of formation multi-layered current sheets inside HPL. FD of a high-speed stream from CH equals 1.7 < FD < 2.0. The fast stream follows HPL transition in positive sector of IMF. In August 2007, 24 and 25.08 from (+) sector IMF a little trace remains: only variations ( - / +) and (+ / -). FD values changes rather essentially (though FD=1.5), but it speaks only about immersing in HPL, without its crossing. The dividing line on the synoptic chart of WSO source surface field proves a true situation. In CR 2060 HPL is not crossed, though HPL has the bend very close to dividing line, fig. 2. С 3 0 «60 SO 1 2 0 IS O l a o 2 IG 2 4 0 2 7 0 ЗОО 3 3 0 0 -J--------- 1 ---------1---------1___________ I___________I___________ 1___________ 1 ___________ 1___________I____________I___________ I___________ L 2 0 6 0 Fig.2 5. C onclusions 1.Geomagnetic activity in solar minimum is caused by co-rotating SW stream (CIR). CIR arises at distribution of high-speed solar wind streams from CHs of minimum phase - CHs of near-equatorial localization. They settle down on background large-scale magnetic fields (data MDI) and are visible on the Sun disk in a soft X-ray (LASCO - the Sun corona; images SOHO EIT, 284A). Recurrent «activity impulses» are provided by these long-lived CHs of solar minimum. 2. The shape o f heliosphere plasma layer (HPL) is reflected in IMF sector structure variations. HPL is long-living phenomenon of SA, which is the most regular in a minimum. 3. In equinoxes we may look the preferred polarity of that solar hemisphere, on which helio-projection of the Earth is realized. It is maximal in an equinox, about 7°. 4. Solar spots of the beginning of new 24-th cycle are weak and have the high-altitude layout. They have no influence on position HPL in minimum. 5. Bends of HPL, flattening to an ecliptic plane, pass in the minimum through low-latitude "old" solar spots, which actually are on the boundary between large-scale background magnetic fields of different polarities. A cknow ledgem ent. The study was supported by Russian Foundation for Basic Research, grant НШ-4573.2008.2. R eferences 1. Bartels J. Terrestrial magnetic activity and its relations to solar phenomena //Terr.Magn.,1932, v.37, №1, P.l-52. 2. ОГ A.I. Geomagnetic disturbance and solar activity // Priroda.1948, №7, P.3-10. 3. ОГ A.I. Solar activity and geomagnetic disturbance connection // In “Physics of solar corpuscular streams and it’s action on upper Earth’s atmosphere”, Publishing house of Academy of sciences of the USSR . 1957, P. 167-174. 97