EFFECT OF SOLAR X-RAY RADIATION AND PROTON PRECIPITATIONS ON THE AMPLITUDE OF VLF SIGNALS

Abstract

The paper aims to analyze and compare the effects and mechanisms of influence on the D and E regions of the ionosphere of the Sun’s X-ray radiation and charged particle precipitations. The work investigates mid- latitude effects, which have not received sufficient coverage in the scientific literature. We analyze changes in the parameters of radio signals received at the IDG RAS Mikhnevo Observatory from European VLF transmitters for a series of events in September 2017, when an X8.2-class X-ray flare and subsequent proton precipitation were observed. Both events lead to an increase in the electron density in the lower ionosphere, but differ in their impact on radio signal parameters. The impact of X-ray radiation leading to an increase in the amplitude of radio signals is observed only in the daytime. The impact of proton rashes is manifested as a nighttime decrease in amplitude.