Analysis of ionospheric disturbances caused by the severe weather event in Poland on 11th August 2017

The coupling of the ionosphere with the tropospheric processes is a complex problem and the necessity of its resolve is highlighted in numerous publications. They mainly focus on lightning, hurricanes, tornadoes, as well as tsunamis, which induce disturbances in the ionosphere. Current works suggest that they are generated by the two major mechanisms: electrical effects during lightning, and atmospheric gravity waves propagated vertically and horizontally. However, these mechanisms are still not precisely examined.

The aim of this study is investigation of the coupling of severe weather event with ionosphere. This phenomenon, which can be classified as derecho occurred on 11th August 2017 in Poland. It was a 300 km length bow echo heavy storm, characterized by wind gusts of about 150 km/h, lightning, strong rain and hail drops. All these factors may have caused disturbances not only in the troposphere but also affect the ionosphere. In order to investigate a coupling mechanism and determination of morphological characteristics of the ionospheric disturbances, we used a dense network of GNSS receivers. Using GPS and GLONASS observations, we estimated total electron content (TEC) variations with 30-second interval. This has allowed to obtain high spatial and temporal resolution maps of ionospheric disturbances which have been compared with other data derived from in situ meteorological measurements, weather radars, and the Weather Research and Forecasting (WRF) numerical weather model. We investigated that during the main phase of the storm the wavy-like ionospheric disturbances occurred for some of the observed satellite with magnitude of about 0.2 TECU. In this work, we present detailed analysis of this event and discussion about troposphere-ionosphere coupling.