The strong IMF fluctuations and their auroral zone geomagnetic response

The purpose of this paper is to investigate relationship between parameters of disturbed solar wind inside the interplanetary shock wave and the high - latitude geomagnetic activity. Data on correlated variations of the IMF, cosmic rays and geomagnetic field at stations of Alaskan region during the extraordinary strong IMF disturbance on October 20, 1989 have been analysed. It is shown that the amplitude of the magnetosonic type fluctuations exceeded significantly the amplitude of the Alfvenic type of fluctuations, and did not show notable correlation with geomagnetic disturbances. At the same time good correlation with the Bz IMF is observed which showed pronounced latitude dependence.