Effects of the Solar Eclipse of March 20, 2015 on the Total Electron Content over Europe

Abstract

The effect of the solar eclipse of March 20, 2015 on variations of the total electron content (TEC) in the ionosphere over Europe is analyzed based on GPS/GLONASS measurements at EUREF network stations. The specific feature of this eclipse is that it occurred under conditions of geomagnetic disturbance remaining after a strong geomagnetic storm on March 17, 2015. This made it more difficult to identify the effects of the solar eclipse. To detect these effects, diurnal TEC variations at individual stations were analyzed. The effect manifested itself as a TEC depression with the minimum close to the time of the maximum phase of the eclipse over the observation station. The effect was more pronounced in TEC variations along the individual passes of the satellites, appearing as a trough-like TEC depression. The diurnal variation of the TEC on the day of the eclipse was significantly different from the nearest control days, which made it difficult to determine the absolute magnitude of the eclipse effect. The space–time behavior of the TEC was represented in the form of TEC maps for the European region. For this purpose, concurrent GPS/GLONASS observations at more than 150 stations were used. A high space–time resolution of the maps made it possible to reveal the dynamics of TEC behavior over Europe during the event under consideration. The eclipse led to a clear change in the structure of the latitudinal and longitudinal TEC gradients. TEC maps generated with a 5-min resolution demonstrate the dynamics of the spatiotemporal behavior of the TEC during the eclipse.