Earth's Ionospheric Response to Solar Activity Phenomena in February-March 2023

Abstract

As a result of the analysis of data from vertical and oblique sounding of the ionosphere in February-March 2023 using the new ionospheric index, it was found that solar coronal mass ejections (CMEs) of the loop type lead to a long-term decrease in the critical frequencies F-layer of the ionosphere, while other types of CMEs may not lead to significant changes in the state ionosphere. The possible role of high-speed streams of solar wind and energetic protons in the occurrence of ionospheric disturbances is noted. Distance-frequency characteristics of the Cyprus-Nizhny Novgorod route during geomagnetic disturbances are given, which indicate both a strong deformation of the F-layer of the ionosphere and the appearance of z-shaped wave disturbances propagating to a region of lower altitudes.