Experimental Study of the Impact of Thunderstorms with Lightning Discharges of Different Polarity on the Ionospheric Parameters

The study was based on 11 years of measurements of ionospheric parameters and atmospheric electric fields reflecting the polarity of lightning discharges and recording return strokes. The response of ionospheric parameters to thunderstorms with lightning discharges of negative and positive polarity under quiet solar and geomagnetic conditions was considered. No changes in the dynamics of ionospheric parameters are observed during thunderstorms with lightning discharges of negative polarity. Variation in the daily course of total electron content and the appearance of wave-like disturbances with a period of 2–5 h are recorded during thunderstorms with lightning discharges of positive polarity. More small-scale disturbances were also detected. Intensification of the sporadic layer was observed in ~70% of the thunderstorm events with positive lightning discharges. A decrease in the height of the sporadic layer Es (h’Es) by 10 km and an increase in the level of radio wave absorption in the D region of the ionosphere were recorded. The experimental results of the study indicate that the polarity of lightning discharges and electromagnetic effects play a decisive role in the process of thunderstorms affecting the ionosphere.