Manifestation of Magnetosphere Fluctuations during the Large Magnetic Storm of January 21-22, 2005

Large-amplitude morning Pc5 magnetic pulsations during the main phase of intense magnetic storm were registered at magnetic stations of 190-200° magnetic meridians on January 21-22, 2005. Magnetic pulsations in the Pc5 frequency range observed at the GOES 10, 12 satellites in the noon and evening sectors exhibited a high degree of magnetic compessibility. A Los Alamos particle detector on board geostationary satellite observed the occurrence of energetic particle flux oscillations in the Pc5 band. The Pc5 pulsations were followed with the VLF-emission and riometer absorption modulation with the same period. The regions of maximal amplitude of Pc5 geomagnetic pulsations and deep modulation of riometer absorptions shifted to high latitudes in the same way. Significant and long-lasting compression of magnetosphere led, probably, to moderate pitch-angle diffusion of particle into the loss cone even at the middle latitudes. Analysis of coordinated data allowed us to suggest that a modulation effects of precipitating particles are caused by a compressional waves.