The effect of variations in solar wind parameters on thunderstorm activity

Findings are presented of the investigation into a possible relation between variations in the intensity of lightnings, measured by the flux of thunderstorm-generated VLF-signals, and variations in solar wind parameters. The signals reflecting the intensity of local thunderstorms in summer are received in Yakutsk (the east of Siberia), and in winter - in the African World Thunderstorm Center. The highest values of the correlation coefficient were obtained in the analysis of the relation between thunderstorm activity and variations of solar wind particle density. We found that this relation has a season-dependent sign-changing character. The maximum positive correlation coefficient is registered in August-September, while the negative one in February; i.e., the effect of maximal manifestation of solar wind density variations in the thunderstorm activity is in preequinoctial periods. This may be associated with the peculiarities of transfer of the magnetospheric electric field "from morning to evening", induced by the solar wind particle flux, to ionospheric heights.