Features of the manifestations of various sources of disturbances in the atmospheric electric field at the Tien-Shan high-mountain station have been studied, and the statistical relationship between solar and thunderstorm activity has been established. Air currents arising over the ocean, having overcome the mountain gorges of the Himalayas, carry moisture to the Northern Tien-Shan and determine the weather features and thunderstorm activity at the Tien-Shan high-mountain station. It was established that the maximum and minimum thunderstorm activity at the Tien-Shan high-mountain station corresponds to the distribution curve of daily thunderstorm activity for the Asia–Australia region. The investigation showed that coronal mass ejections (CMEs) affect the atmospheric electric field by increasing or decreasing its level or causing its fluctuations, depending on the features of manifestations in the near-Earth space and in the Earth’s magnetosphere. In at least 70% of cases, thunderstorm activity was observed with a 1–2-day delay after impact on the Earth’s magnetosphere by CMEs and HSSs. A number of cases were studied when thunderstorm activity was observed in a quiet geomagnetic field. In these cases, an increase in the values of fmin (the minimum frequency of reflection from the ionosphere) and foEs (the critical frequency of the sporadic E layer) was observed, which indicated an increase in the level of radio wave absorption in the ionospheric D-region and the level of electron density at altitudes of 100–120 km.

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.

The article analyzes the spatiotemporal structure of thunderstorm activity and local electric-field changes in the Northern Tien Shan region based on data from the global WWLLN network and local measurements of the atmospheric electric field obtained by the ELIS-TS complex during 2013–2025. The main thunderstorm season from April to October is considered. During this period, the ELIS-TS complex recorded 3603 events, of which 74.6% were accompanied by negative electric-field changes and 25.4% by positive electric-field changes. Peak activity occurs from June to July, which coincides with the period of maximum convection in this region. A comparison of local measurements with WWLLN data showed that the largest number of recorded electric-field disturbances corresponded to WWLLN-detected events located within the first tens of kilometers from the station. Spatial analysis revealed an increased density of lightning discharges in mountainous and foothill areas, as well as a seasonal shift in thunderstorm activity due to the orographic influence of the terrain. Dividing the study area into lowland and mountainous zones revealed differences in the diurnal activity pattern: the peak occurs earlier in the mountains, indicating earlier convective development over high-altitude terrain.

Total electron content measurements by using dual-frequency signals of global navigation satellite systems (GNSS) makes it possible to obtain the global distribution of electron density of ionosphere with high spatial and temporal resolution. Such high spatial and temporal resolution allows to explore of small-scale traveling ionospheric disturbances generated by terrestrial geophysical events, including seismic activity, solar terminator passage, and atmospheric cyclones. One of the features of measuring the total electron content of the ionosphere with GNSS is that the measurements are made at the line of intersection of the satellite-receiver beam with the layer of maximum ionization of the ionosphere at height of ≈ 300 km. At the same time, due to the orbital motion of the satellites and the Earth rotation, the ionospheric points at which the measurements are providing carrying out a movement relative to each other, relative to the Earth and relative to the traveling ionospheric disturbances. Such a relative motion of the measurement points causes the occurrence of the Doppler effect and leads to a distortion of the wave parameters of the total electron content variations. In particular, the determination of the period of traveling ionospheric wave disturbances on the basis of time series leads to large distortions depending on the used satellite, the time and coordinates of the receiver. This paper describes a method for determining the exact wave parameters –frequency, wavelength, and propagation velocity of traveling ionospheric wave disturbances, based on the use of godochrones to analyze TEC variations. The difference between the wave parameters measured by the proposed method and from the time series of TEC data is shown on an example of wave disturbances generated by the passage of solar terminator.

The possible impact of solar activity on the atmospheric electric field, thunderstorm activity and lower ionosphere was investigated. The investigation was based on the electric field measurements and ionospheric observations at Alma-Ata (Kazakhstan). The investigation showed a decrease in the atmospheric electric field (~40 ÷ 50 V/m) under “fair” weather conditions, fluctuations under magnetic storms, and anomalous changes before and during significant and weak earthquakes. The study indicated a tendency for thunderstorm appearance with a 1–2-day delay after the impact of CME or HSS events on the Earth’s magnetosphere. Noticeable changes in the lower ionosphere during these periods were found.