Ionospheric Response to the Geomagnetic Storm of 20th April 2020 over Different Latitudinal Areas

Year 2020 marks the beginning of the 25th solar cycle and repeats the period 2009, which had exceptionally low long lasting solar activity. Therefore, although this paper is devoted to the response of the ionosphere to the strongest disturbance in 2020, the results of a comparison of climatology in 2009 and 2020 were obtained, which showed a certain identity, especially important for the equivalent slab thickness of the ionosphere, which allows filling the gaps in the data on the critical frequency foF2 using the total electron content TEC to study the response of the ionosphere. In this paper, such a study was carried out near the meridian of the European part of Russia for the disturbance on April 20, 2020 according to data from 5 ionosondes. A distinctive feature of this response is a positive disturbance in the behavior of TEC and electron density, confirmed by data from the SWARM satellite and associated with the peculiarities of the influence of space weather parameters.