ИСТИНА

Energetic electrons of tens keV range are responsible for a whole range of ionospheric effects through ionization and excitation of atmospheric neutrals from low to high latitudes. The particle-produced ionization results in such ionospheric effects as increases of plasma density and positive ionospheric storms, ionospheric irregularities and scintillations, polar cap absorption effects and aurora/optical emissions. In distinction from well-known ionospheric effects caused by precipitating electrons at high latitudes, the ionization impact at low latitudes are a very new subject for the ionospheric research. Recent studies showed that the ionization effects at low latitudes become significant mainly during geomagnetic disturbances, when intense energetic electron fluxes penetrate from the radiation belt into the F-region and topside ionosphere in the equatorial region. We present results of a statistical study as a first step in creating a forecasting model of the energetic electron enhancements in the equatorial ionosphere.