Monitoring solar activity during 23/24 solar cycle minimum through VLF radio signals

Abstract

. Solar activity during solar minimum between 23 rd and 24 th solar cycle was inspected, based on solar X-ray radiation listings from Geostationary Operational Environmental Satellite (GOES) database. Periods of quiet solar conditions with low background X radiation are particularly favourable for analysis and exploration of low intensity solar flare events and their effects on lower ionosphere. Low intensity solar flare events were monitored and examined through Very Low Frequency (VLF) radio signals (3-30 kHz), recorded by the use of Absolute Phase and Amplitude Logger system (AbsPAL) operating at the Institute of Physics Belgrade, Serbia. For the purposes of numerical modeling of low ionospheric response to low class solar flare events, the Long Wave Propagation Capability (LWPC) software, based on Wait’s theory, was applied. Main results are presented in this paper.