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.

О. V. Kozyreva and N. G. Kleimenova wind speed in the compression region (Vmin) and the maximum (Vmax) of the velocity o f HSS. The storm № 11 is CME- storm (14-16.12.2006), for this storm we give Vmin as the value of the solar wind speed prior to the storm. It is evident from the table that in all considered CIR- storms, in spite of the great significances of density (15-65 cm-3) and velocity (620-720 km/s) of the solar wind, the Dst-index was small. For the analysis of the ground-based Pc5 activity we used the ULF-index [Kozyreva et al, 2007], characterized the intensity of the pulsations in the range of 2-7 mHz, and calculated from 1-min data of the global magnetometer network of the northern hemisphere. As an example we consider the Pc5 pulsation during the CIR-storm on May 9-14, 2006 (Fig.l). One can 09-14 M AY 2006 Fig. 1. The variations in the velocity (V) and the density (N) of solar wind, Bz component of IMF, Dst- and AE- indices, and also ULF- of index for the auroral and polar zones in the forenoon and post-noon sectors the magnetic storm on Mav 09-14. 2006 (CIR-storm). see that during the initial phase o f this storm (interval 1) the most intensive Pc5 pulsations were observed in the pre-noon sector of polar latitudes. During the main phase o f storm (interval 2) the ULF- index grew both in the polar and in the auroral latitudes, the sharp increase of the wave activity coincided with the AE- index enhancement. During the recovery phase of storm (interval 3 and 4) the solar wind velocity remained high (about 600 km/s), and the AE-index attained 400-500 nT. The most intensive ULF were observed in the pre-noon sector of the polar latitudes. The similar Pc5 pulsations distribution was found in all considered CIR-storms: the storm initial phase is characterized by the Pc5 enhancement in the pre-noon sector of the polar latitudes; the storm main phase - the Pc5 enhancement in the pre-noon and afternoon on the polar latitudes, the pulsations amplitude grows with the AE-index; in the storm recovery phase the most intensive Pc5 pulsation are observed also in the pre-noon sector o f the polar latitudes. Thus, during all phases o f CIR-storm the most intensive Pc5 pulsations are observed on the latitudes higher than 70° and predominantly in the pre-noon time. As it was reported in the papers [Kozyreva and Kleimenova, 2008, 2009], the spatial distribution of Pc5 pulsation during CME-storms demonstrates the different signature. The initial phase of CME- storm is characterized by the intensive ULF waves in the morning sector o f the polar and auroral latitudes. In the storm main phase, the strongest Pc5 pulsations are observed in the morning sector of the auroral zone during the development of substorms. In the storm early recovery phase the wave activity still remained in the morning sector of the auroral zone, but in the late recovery phase it shifts to the higher latitudes. The similar spatial characteristics o f the Pc5 pulsations were observed during the strong CME- storm on December 14-16, 2006 (Fig. 2), caused by series o f powerful solar flares. Conditions in the solar wind and in Bz IMF during this storm are shown in the upper panels o f Fig. 2. Velocity o f solar wind was very strong and reached ~900 km/s, the maximum of the solar wind density was small (-10 cm'3) in comparison with the previous CIR-storms (see Table). In contrast to the discussed CIR-storms, the solar wind velocity was large even in the storm initial phase (on December 14). The bottom panels o f Fig. 2 demonstrate the spatial- temporal dynamics o f the ULF activity during this CME magnetic storm. One can see that in the initial phase (interval 1) the most intensive waves were recorded in the pre-noon and afternoon sectors at the polar latitudes. In the storm main phase the maximum of the ULF-index were, at least, 4-5 times it is higher than in the considered CIR-storm on May 09-14, 2006 (Fig. 1) and was observed in the pre-noon sector mostly at the auroral latitudes (interval 2). 34