Investigation on Chasing and Interaction of Traveling Ionospheric Disturbances Based on Multi‐Instrument

In this study, we use multi‐instrument observations (all‐sky imager (ASI), global navigation satellite system (GPS) receivers, digisonde) to study the interaction of nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) on 13 November 2018. The most attractive aspect of this event is that the interaction appeared between two dark bands both propagated southwestward. The airglow observations show that the latter band moved faster and caught up with the former, and these two bands merged into a new one. The propagating characteristics and morphology of the MSTIDs changed during the interaction process. The simulations from the Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM) suggested that the ionospheric background zonal winds and electron density distributions could play essential roles in the interaction of the MSTIDs. Moreover, the merging process might be associated with the electrostatic reconnection. This study shows an interesting medium‐scale traveling ionospheric disturbance (MSTID) event. Two MSTID bands encountered during the propagation, the latter dark band caught up with the former band, and then, the two bands merged into one. In contrast, these dark bands kept propagating southwestward. The Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM) simulations obtain the wind and electron density data, which provide a possible explanation that the changing of ionospheric zonal winds and ionospheric electron density might result in the interaction of these dark bands. Moreover, the merging process might be connected with the electrostatic reconnection, which could be influenced by E×Bplasma flows in opposite directions. Two bands propagated southwestward, the latter band moved faster and caught up with the former, they interacted and merged into oneThe chasing behavior showed the velocity differences, possibly related to the ionospheric zonal wind and electron density distributionThe merging process of the two bands might be connected with electrostatic reconnection Two bands propagated southwestward, the latter band moved faster and caught up with the former, they interacted and merged into one The chasing behavior showed the velocity differences, possibly related to the ionospheric zonal wind and electron density distribution The merging process of the two bands might be connected with electrostatic reconnection