Ionospheric response to the 2018 sudden stratospheric warming event at middle- and low-latitude stations over China sector

摘要

The total electron content (TEC) recorded at two middle-latitude stations (Mohe and Beijing), and four low-latitude stations (Xiamen, Guangzhou, Nanning, and Kunming) in the China sector are analyzed to study the response of the ionosphere during the sudden stratospheric warming (SSW) event in February 2018. The TEC and deviation of TEC (Delta TEC) present remarkable perturbation after the reversal of the zonal wind during the SSW period. The Delta TEC presents enhancement during the daytime and decreases after sunset, especially around the temperature peak. Results of wavelet power spectra analysis show that the Delta TEC shows intensive semidiurnal and diurnal oscillations during the SSW period. The percentage of dTEC exhibits moderate correlation with solar geophysical drivers (such as solar wind speed, F-10.7, and Ap index) during the period of 11-26 February at low-latitude stations. The significant correlation between equatorial electrojet and the percentage of dTEC monitored at low latitude indicates that the equatorial electrojet plays a key role in the anomaly perturbation and periodic oscillation of TEC, while it has a weak correlation at middle latitude.