ИСТИНА

Recent observations revealed events of energetic and relativistic electron enhancements in the Earth’s radiation belt (ERB) occurred on timescales of less than a few hours. As it was shown, so-called “rapid rebuilding” events were caused by substorms. We found that similar enhancements were also seen under the ERB in the forbidden zone. Both phenomena of sudden growth of energetic electrons inside and under the ERB relate to substorm dipolarizations, which result in rapid changes in the configuration of the magnetic field and generation of inductive electric fields. In the previous studies we found very intense fluxes of energetic electrons in the forbidden zone which resulted in substantial abundant ionospheric ionization during strong magnetic storms. Here we analyze enhancements of >30-keV quasi-trapped electrons during a moderate recurrent (CIR/HSS-driven) geomagnetic storm on 22 July 2009. We focus on particular issue of the magnetosphere-ionosphere coupling through the quasi-trapped electrons at low-latitudes. We show that unusually large area in the nighttime ionosphere with increased total electron content (TEC) and prominent elevation of the F-layer at low-latitudes coincides spatially and temporarily with enhanced electron fluxes. Ionizing particles are considered now as an addition source of ionization during recurrent magnetic storms along with generally accepted mechanisms for storm-time TEC increases or so-called positive ionospheric storms.