A study on the propagation and evolution of MSTID events in China's low-latitude region during 7–8 December 2019

This study investigates a nighttime medium-scale traveling ionospheric disturbance (MSTID) event observed over the low-latitude Fuke Station (19.5°N, 109.1°E) in China on December 7–8, 2019. The analysis incorporates airglow data from the Chinese Meridian Project, digisonde observations, and simulations from the Thermosphere–Ionosphere Electrodynamics General Circulation Model (TIE-GCM). The results show that the observed structures correspond to typical Northern Hemisphere MSTIDs, with bands aligned in the northwest–southeast direction and propagating southwestward. During propagation, a chasing phenomenon occurred in which the latter dark band caught up and interacted with the earlier one. The TIE-GCM simulations suggest that the chasing process was primarily governed by the combined effect of the gradient in the background zonal wind and the enhanced electron density distribution within the equatorial ionization anomaly region at low latitudes.