Contrasting behavior of the F2 peak and the topside ionosphere in response to the 2 October 2013 geomagnetic storm

摘要

In this study, the ionospheric observations from ionosondes, ground-based GPS receivers, Gravity Recovery and Climate Experiment (GRACE) and MetOp-A satellites, and Fabry-Perot interferometer over the Asian-Australian sector have been used to investigate the responses of the F_2 peak and the topside ionosphere to the 2 October 2013 geomagnetic storm, particularly during the recovery phase. The comparison between the multiple simultaneous observations revealed a contrasting behavior of the topside ionosphere and the F_2 peak in East Asia during the recovery phase. The upward looking total electron content from low-Earth orbit (LEO) satellites did not undergo such depletions as seen in the region near the F_2 peak, and they even showed increases. Furthermore, the simulation results of the Thermosphere Ionosphere Electrodynamics General Circulation Model are used to explore the possible mechanisms responsible for the observed features. The model results and observations suggested that the contrasting behavior of the F_2 peak and the topside ionosphere is mainly associated with the enhancement of the equatorward winds, albeit the disturbed electric fields could play an important role in producing it.