# Near-Real-Time Global Thermospheric Density Variations Unveiled by Starlink Ephemeris
## 5 Conclusions  
In this study, we conducted a comprehensive assessment of the capability of SpaceX's publicly available Starlink predicted ephemeris data to capture thermospheric density variations. Based on the unique characteristics of Starlink ephemeris data, a maneuver detection algorithm utilizing mean orbital elements is applied. Statistical analysis of the maneuvers in Shell 1 reveals that satellites perform routine maneuvers covering all orbital planes approximately every two days. In addition to the routine maneuvers, the maneuver frequency of Starlink satellites increases significantly during periods of thermospheric disturbance. This suggests that the maneuver frequency of Starlink satellites can serve as a preliminary indicator of thermospheric disturbance conditions. The thermospheric density retrieval method based on energy conservation principles is employed to calculate the 1-min resolution mechanical energy loss for each Starlink satellite, and the mechanical energy loss derived from Starlink ephemeris data has been compared with thermospheric density changes observed by the Swarm-B satellite during both quiet and disturbed geomagnetic conditions. The results demonstrate that Starlink's mechanical energy loss effectively captures thermospheric density variations, although it does not match the accuracy of the results from post-processed POD data. While Starlink ephemeris data provide valuable insights into thermospheric density variations, they still exhibit certain limitations in accurately capturing these changes. These limitations may arise from factors such as the effective resolution of the dataset. For instance, discrepancies between ascending and descending orbit segments highlight the limitations inherent in the orbit extrapolation model used in prediction ephemeris, which suggests that the extrapolation model is better suited for capturing broad thermospheric trends rather than fine-scale variations. The Starlink ephemeris represents a vast and valuable database. With its 8-h update cycle, as well as the global coverage and multi-altitude deployment, the Starlink ephemeris enables near-real-time monitoring of the global thermospheric density. Future research can leverage the unique advantages of Starlink ephemeris to advance our understanding of the space environment dynamics and improve the space weather forecasting capabilities. Conceptualization, Z.O., J.Z., Y.H., R.L. and X.W. ; methodology, J.Z., R.L. and X.W. ; software, Z.O., J.C., K.W., H.H. and X.S. ; validation, J.Z., Y.H., R.L. and X.W; formal analysis, Z.O., J.C., H.H., W.D. and Y.T. ; investigation, J.Z., Y.H. and X.W. ; resources, Z.O., J.Z., Y.H. and X.W. ; data curation, Z.O. ; writing--original draft preparation, Z.O. and J.Z. ; writing--review and editing, J.Z., Y.H., R.L. and X.W. ; visualization, [PERSON], [PERSON], J.C. and W.D. ; supervision, [PERSON] and J.Z. ; project administration, [PERSON] and Y.H. ; funding acquisition, [PERSON] and Y.H. All authors have read and agreed to the published version of the manuscript. This work was supported by the National Natural Science Foundation of China (42374181, 42374186, 42104169, and 42441814); Guangdong Basic and Applied Basic Research Foundation (2021A1515011216 and 2022A1515011580); China Postdoctoral Science Foundation (2023M733363). Key Innovation Team of China Meteorological Administration 'Space Weather Monitoring and Alerting' (CMA2024 ZD01); 'Ionospheric Forecast and Alerting' Youth Innovation Team (CMA2024 QN09); the Strategic Priority Research Program of Chinese Academy of Sciences (XDB41000000); Key Laboratory of Tropical Atmosphere-Ocean System (Sun Yat-sen University); Ministry of Education; the Fundamental Research Funds for the Central Universities; the Opening Funding of Chinese Academy of Sciences dedicated for the Chinese Meridian Project; and the Open Research Project of Large Research Infrastructures of CAS--\"Study on the interaction between low/mid-latitude atmosphere and ionosphere based on the Chinese Meridian Project\".