Magnetosphere-ionosphere response to magnetosphere compression by the solar wind

Analysis of the global magnetosphere-ionosphere response to solar wind dynamic pressure variations under the negative IMF Bz has been performed. It is shown that an increase in the dynamic pressure leads to a double response of the ionospheric currents and aurora, i.e. simultaneously (within the accuracy of 1 min) and ~5-7 min afterward. Thereby, the eastward and westward convective electrojets are enhanced in the evening and morning sectors respectively, followed by the intensification of the westward current in the near midnight and evening sectors. The intensification of the electrojets is followed by extension of the diffuse precipitation zone and its high latitude boundary movement to the pole and to the east in the midnight-to-morning sector. In our case, no poleward or westward extension of aurora before midnight is observed. The disturbance triggered by a dynamic pressure increase may be considered as a convection disturbance associated with reconstruction of the DP2 current system.