Analysis of GPS-TEC at polar conjugate stations during 2003 equinoxes

The solar energy affects on the ionosphere is of a major concern and is being investigated worldwide. As the ionosphere is an ever changing-medium it is difficult to precisely determine the TEC, which is also subjected to seasonal variations. Conjugate stations allow excellent opportunities to learn any asymmetric properties and its phenomena. With these respects, this paper examine the GPS derived TEC variations during the vernal and autumnal equinoxes period for the year 2003 at the polar conjugate stations. A month of GPS TEC data (two weeks before and after the equinox onset) at Scott Base station, Antarctica (SBA) and the Canadian Resolute Cornwallis Island station (RESO), Artic are analyzed. Results show that mean TEC during vernal equinox (VE) is higher at SBA than at RESO by about 12.5% and during autumnal equinox (AE) it is higher at RESO than SBA by about 12.6% with both conjugate stations having approximately similar total mean TEC during the equinoxes (VE+AE) of about 21 TECU. This preliminary investigation shows the potential of seasonal effects at high latitudes conjugate stations towards a better characterization of the ionospheric TEC.