The understanding of the impact of solar activity on polar regions upper atmosphere is not as strong as compare to low and mid-latitudes due to lack of experimental observations, especially over Antarctica. To characterize the differences in the ionosphere-plasmasphere total electron content (TEC) climatological patterns over Antarctica, we reprocessed the GNSS (GPS + GLONASS) data available since 1999 up to now for stations situated at latitudes below S50°. For that, we used the data from POLENET/IGS networks and stations installed around the Princess Elisabeth polar Base (Utsteinen, North-East Antarctica). The estimated TEC data set is then employed to constrain an empirical model to predict the TEC from F10.7P solar index in entrance using a least-square adjustment. To minimize the differences between the modelled and observed vTEC we considered: (1) an eight-order polynomial function with monthly coefficients between the TEC and F10.7P; (2) a discretization with respect to different zones over Antarctica region to highlight different climatological patterns; (3) different time definitions such as Solar Local Time, Magnetic Local Time, and UTC. From the output of this model we discuss the different climatological behaviors identified in the ionosphere- plasmasphere TEC at these high latitudes. Finally, we show some examples of typical TEC disturbances observed during extreme solar events.
Dr Nicolas Bergeot (Royal Observatory of Belgium)
Mr Jean-Marie Chevalier (Royal Observatory of Belgium)