Seasonal and solar activity dependence of TEC over Bharati station, Antarctica

The total electron content (TEC) is a key parameter that is used to understand the effects of ionosphere on satellite-based navigation and communication signals. The ionosphere at polar is highly dynamic and acts as a major sink for the solar-terrestrial energy transfer processes, different magnetospheric and space weather events. Especially in Antarctica, the observation is still sparse due to a limited number of stations. In this paper, the study of ionosphere variability over Bharati station (69.41° S, 76.19° E), an Indian Antarctic research base at Larsemann Hills, was carried out. During the geomagnetically quiet conditions, the Bharati station is located outside of auroral oval but towards the poleward of auroral oval. The variation of ionosphere for diurnal, seasonal, and solar activity was studied using the TEC data for the years 2010–2022 which covers the solar cycle 24. The TEC diurnal pattern is strong even during polar days and nights with a peak at local noon. The seasonal variability was distinctly observed with about 50% increase in TEC during equinoctial months compared to summer months during high solar active year 2014. However, during low solar active year there is a marginal increase of TEC in equinoxes compared to summer.