Satellite & Space Missions

Biography

Biography: Oleg Troshichev

Abstract

The space weather monitoring basically rests on of the solar wind measurements outside of the magnetosphere. The ground-based index of the polar cap magnetic activity (PC) is regarded as index characterizing the energy that entered into the magnetosphere. The following relationships between the PC-index and the solar wind parameters, on the one hand, and relations between the PC evolution and the magnetospheric substorms (AL index) and magnetic storms (Dst index) development, on the other hand, provide this concept: (1) the PC index is perfectly correlates with the interplanetary electric field (EKL), (2) delay time ΔT in response of PC index to EKL variations is controlled by the EKL field growth rate (dEKL/dt) and does not depend on such solar wind parameters, as solar wind speed VX and IMF BZ component, (3) magnetic storms and substorms are always preceded and accompanied by РС index growth, (4) substorms and magnetic storms start to develop as soon as the PC index steadily exceeds the threshold level of 1.5 mV/m, (5) the substorm sudden onsets are commonly associated with a sharp increase in the PC (and EKL) growth rate, (6) linear correlation between the PC and AL values is typical for all classes of the substorms, (7) maximal depression of magnetic field responds to maximal PC value with a delay of ~1 hour, the storm intensity (Dstmin) being linearly depending on PCmax value. The PC index can be used as a reliable ground-based means for exploration of short-term changes in space weather and magnetosphere state.