Interplanetary sources of space weather disturbances in 1997 to 2000

Abstract

Seventy‐five disturbed intervals from 1997 through 2000 were analyzed and selected on the basis of space weather effect occurrences such as significant compression of the dayside magnetosphere, strong magnetic storms, ionospheric perturbations, relativistic electron enhancements, and increases in the rate of data failures and radiation doses on board the Mir station. Solar wind disturbances were considered as the main factor influencing the Earth's magnetosphere. We distinguished four geoeffective interplanetary (IP) phenomena: interplanetary coronal mass ejections (ICME), interplanetary forward shocks with compressed region (IS), fast solar wind streams from coronal holes (CH), and corotating interaction regions (CIR) between the CH and relatively slow ambient solar wind. Each selected interval was studied and classified under the IP phenomena that it was a direct consequence of. It was found that IP phenomena “containing” ISs, ICMEs, and CIRs were mostly responsible for geosynchronous magnetopause crossings, strong geomagnetic storms, and intensification of geomagnetically induced currents. The fast solar wind streams from coronal holes controlled mainly geosynchronous relativistic electron enhancements. The rate of data failures and variations of the radiation dose on board the Mir station were related to both IS‐ICME and CIR‐CH phenomena. Such a relationship was interpreted in terms of (1) decrease of cutoff threshold for solar energetic particles due to the magnetospheric compression and/or ring current intensification on the main phase of geomagnetic storms and (2) intensive relativistic electron precipitation from the outer radiation belt and its contribution to the radiation conditions at low altitudes during recovery phase of recurrent magnetic storms.