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.

V.B. Belakhovsky at al. The variations of the proton density at ACE, GEOTAL, and WIND spacecraft and the magnetic field at Abisko (ABK) station during morning and afternoon intervals are shown in Fig.l. WIND spacecraft is located in the solar wind, but in the tailward direction. GEOTAIL spacecraft crosses the boundary between the magnetosphere and magnetosheath in the morning flank. A detailed examination shows a close connection between the solar wind density variations and the magnetic field variations on the ground. We suppose that geomagnetic Pc5 pulsations on IMAGE profile stations (noon at -14 UT) have been triggered by enhanced solar wind density variations. The vectors of the plasma velocity V and electric field E in the ionosphere have been computed using data from receivers at SOD and KIR. For both intervals when Pc5 pulsations are observed on IMAGE profile the hodographs of the ionospheric electric field E and the hodographs of the ground magnetic field В from TRO have been computed (Fig. 2,3). Fig. 1. Proton density at ACE, GEOTAL, WIND spacecrafts and magnetic field at ABK station for the morning (left panel) and afternoon (right panel) Pc5 pulsations. 31 O ctober 2003, 05.30-06.30 UT. 4 .3 -4 .9 mHz. T"~' ‘ 1 ■ I ' ' ' ' I 1 1 I I ' 1 ' ' I У-com ponent Ey-com ponent Fig. 2. Hodographs of the magnetic field at TRO station (left-hand panel) and the electric field obtained from EISCAT radar data (right-hand panel) in the interval 05.30-07.00 UT at 31 October 2003. 70