Physics of auroral phenomena : proceedings of the 36th Annual seminar, Apatity, 26 February – 01 March, 2013 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2013. - 215 с. : ил., табл.

О. V. Kozyreva and N. С. Kleimenova According to Fig. 2, the amplitude of the ULF fluctuations in the SW density ( ULF_N) composed -1/15 - 1/20 of the value of the SW number density and the amplitude of the ULF fluctuations in the IMF В ( U L F B ) - about 1/5 of the value of the total IMF B. The strong variations of SW and IMF parameters, associated with CIR structure passage, have to affect on the magnetosphere ULF wave generation, for example, on the excitation o f field line resonances [e.g., Walker, 2002; Kessel, 2008]. To the present time, there are no detailed studies of the geomagnetic effects separately o f ULF_N and ULF_B during the HSSs passage. But the general properties of ground-based ULF pulsations during 10 successive recurrent storms of 2006 (this interval is part of discussed here solar activity minimum) have been analyzed by Kozyreva and Kleimenova [2010]. It was found that in a CIR storm initial phase, correspondent to HSS passage, the (2-7) mHz geomagnetic pulsations were mainly observed at the geomagnetic latitudes higher than 70° the morning or prenoon local time. These waves could be associated with the ULF_N and/or ULF_B of HSSs, directly penetrating into open polar cap or guiding by magnetopause with nonlinear transformation in the magnetosphere turbulent boundary layers. 4. Conclusion The statistical analysis of the level of the ULF fluctuations in the frequency range o f (2-7) mHz in the solar wind density (Np) and total magnetic field IMF B, computed by using special ULF- index [Kozyreva et al., 2007], based on the 1-min OMNI data, has been performed for the set of 63 events of the high speed solar wind streams (HSSs) during the solar activity minimum (2006-2009). We found that the strongest amplitudes of the ULF fluctuations in Np and IMF В were recorded in the front edge of the HSSs which had the form of the corotating interactive regions (CIR). The amplitudes of the ULF fluctuations, both in Np and IMF, strongly increased with increasing the solar wind density and В IMF. The amplitude maximum of the fluctuations in the SW density ( ULF_N) observed under low SW speed prior to the stream interface and was ahead (~4 hours) the amplitude maximum o f the fluctuations in the В IMF ( ULF_B ), which was observed around the stream interface. A cknow ledgem ents. This work was supported by RFBR grant 12-05-01030 and partly 13-05-00233. References Borovsky, J.E., and H.O. Funsten (2003), Role of solar wind turbulence in the coupling o f the solar wind to the Earth’s magnetosphere, J. Geophys. Res., 108(A6), 1246, doi: 10.1029/2002JA009601. Borovsky, J.E., and M.H. Denton (2010), Solar wind turbulence and shear: A superposed-epoch analysis of corotating interaction regions at 1 AU, J. Geophys. Res., 115, A10101, doi: 10.1029/2009JA014966. Denton, M.H., and J.E. Borovsky (2008), Superposed epoch analysis of high speed stream effects at geosynchronous orbit: Hot plasma, cold plasma, and the solar wind, J. Geophys. Res., 113, A07216, doi:10.1029/2007JA012998. Forsyth, R.J., and E. Marsch (1999), Solar origin and interplanetary evolution o f stream interfaces, Space Sci. Rev., 8 9 , 7, doi: 10.1023/A: 1005235626013. Horbury, T.S., and A. Balog (2001), Evolution of magnetic field fluctuations in high-speed solar wind streams: Ulysses and Helios observations, J. Geophys. Res., 106, AOS, P. 15,929-15,940. Kozyreva, O., Pilipenko V., Engebretson M.J., Yumoto K., Watermann J., and N. Romanova (2007), In search of a new ULF wave index: Comparison of Pc5 power with dynamics o f geostationary relativistic electrons Planet Space Sci. 55, 755-769. Kozyreva, O.V., and N.G. Kleimenova (2010), Variations in the ULF index o f daytime geomagnetic pulsations during recurrent magnetic storms, Geomagnetism and Aeronomy, 50 (6), 770-780. Kessel, R.L. (2008), Solar wind excitation of Pc5 fluctuations in the magnetosphere and on the ground J. Geophys Res., И З, A04202, doi:10.1029/2007JA012255. " ' " ............. Richter, A.K., and A.H. Luttrell (1986), Superposed epoch analysis o f corotating interaction regions at 0.3 and 1.0 AU: A comparative study, J. Geophys. Res., 91, 5873, doi:10.1029/JA091iA05p05873. Romanova, N., and V. Pilipenko (2009), ULF wave indices to characterize the solar wind - magnetosphere interaction and relativistic electron dynamics, Acta Geophys., 57(1), 158-170, doi: 10.2478/sl 1600-008-0064-4. Tsurutani, B. et al. (2006), Corotating solar wind streams and recurrent geomagnetic activity A review J Geophys Res., I l l , A07S01, doi:10.1029/2005JA011273. Walker, A.D.M. (2002), Excitation of field line resonances by MHD waves originating in the solar wind J. Geophys. Res., 107, A12, doi:10.1029/2001JA009188. 116