## 5 Conclusions  
The analysis in this study was performed by utilizing TEC data obtained from the BeiDou GEO satellite based on CMONOC. We investigated the ionospheric disturbances preceding the Jiuzhaigou Ms7.0 earthquake in 2017 and explored the potential LAIC mechanism. Here, we summarize our main conclusions as follows:  
1. In the context of relatively stable solar and geomagnetic activity, ionospheric disturbances were observed near the epicenter of the Jiuzhaigou earthquake--specifically, 10 to 11 days, 6 to 7 days, and 1 to 9 h before the earthquake. 2. On the spatial distribution, the anomalous TEC data prior to the earthquake were predominantly located in the southeast and southwest directions from the epicenter, with the disturbances primarily concentrated within a range of 2500 km. 3. Comparing the perturbation information of radon gas, atmospheric electric field, and TEC time-frequency with the TEC perturbation in terms of time and characteristics, it was concluded that both the chemical and acoustic pathways may play important roles in the gestation process of the Jiuzhaigou Ms7.0 earthquake. Understanding how earthquakes and ionospheric disturbances are interrelated is a complex research topic that requires a comprehensive investigation methodology, incorporating various factors and an interdisciplinary approach. In order to gain a more comprehensive understanding of the intricate relationship between earthquakes and the ionosphere, future research should concentrate on delving into the interactions between various contributing factors and determining their correlation with seismic activities. This will facilitate a more comprehensive understanding of the intricate relationship between earthquakes and the ionosphere, leading to the development of a more accurate and reliable information platform for earthquake prediction and monitoring. The positions of IPPs detected by GPS satellites undergo changes due to the movement of these satellites. Therefore, the GPS data alone cannot directly represent the temporal variations of the TEC at specific locations in the ionosphere. To mitigate this issue, the data need to undergo mathematical interpolation or modeling techniques, coupled with high-frequency sampling, in order to minimize errors. However, BeiDou GEO satellites  
Figure 8: Time–frequency plots of TEC at the six IPPs in Figure 7.  
possess unique stationary characteristics enabling them to continuously monitor the electron content along fixed paths. As a result, BeiDou GEO satellite data can more accurately reflect the continuous variations of the ionosphere at specific locations [79]. Leveraging high-spatiotemporal-resolution data from BeiDou GEO satellites, this study unveiled the disturbance characteristics of TEC in the hours preceding an earthquake. For future research, it is anticipated that the advantages of BeiDou GEO satellite data can be fully demonstrated by analyzing more earthquake cases, contributing to a further comprehensive understanding of ionospheric disturbances triggered by earthquakes. Conceptualization, [PERSON], [PERSON] and X.Z. ; methodology, [PERSON]; software, [PERSON]; validation, [PERSON], [PERSON] and [PERSON]; formal analysis, [PERSON] and [PERSON]; investigation, [PERSON] and [PERSON]; resources, [PERSON] and [PERSON]; data curation, [PERSON] and [PERSON]; writing--original draft preparation, [PERSON] writing--review and editing, [PERSON] and [PERSON]; visualization, [PERSON]; supervision, [PERSON] and [PERSON]; project administration, [PERSON] and X.Z. ; funding acquisition, [PERSON] and X.Z. All authors have read and agreed to the published version of the manuscript. This research was funded by the APSCO Earthquake Research Project Phase II, and ISSI-Beijing (2019-IT33). F10.7 index is available at the website [[http://www.sepc.ac.cn](http://www.sepc.ac.cn)]([http://www.sepc.ac.cn](http://www.sepc.ac.cn)) (accessed on 12 August 2023).