# Near-Real-Time Global Thermospheric Density Variations Unveiled by Starlink Ephemeris
## 3 Results  
In this section, we analyze the mechanical energy loss results derived from Starlink ephemerides in October 2024. This period comprised two consecutive geomagnetic storms. The first was relatively moderate, whereas the second constituted a strong magnetic storm. Figure 3 presents the interplanetary and geophysical parameters during the storm events. The solar flux proxy F10.7 remained elevated, signifying heightened solar activity. The onset of the first storm was marked by abrupt enhancements in solar wind velocity and density at approximately 06:00 UT on 6 October. Concurrently, the interplanetary magnetic field (IMF) \(B_{z}\) and \(B_{y}\) components exhibited pronounced fluctuations. Subsequently, the AE and Kp indices surged to peak values of 1500 nT and 7, respectively, while the disturbance storm time (Dst) index plummeted to a minimum of \(-\)150 nT. As the effects of the first storm subsided, a strong magnetic storm commenced at around 13:00 UT on 10 October. A Coronal Mass Ejection (CME) shockwave arrived at nearly 12:00 UT, characterized by rapid increases in solar wind velocity (from 658 km/s to 749 km/s within one hour) and density (from 7.1 cm\({}^{-3}\) to 34.5 cm\({}^{-3}\)). The IMF \(B_{z}\) component displayed extreme southward orientation, reaching a peak value of \(-\)42.2 nT at 23:00 UT on 10 October, while \(B_{y}\) oscillated between \(-\)22.9 nT and 20.2 nT. Simultaneously, the AE and Kp indices escalated sharply to 3500 nT and 8.7, respectively, accompanied by a positive sudden impulse in the Dst index, identified as a Sudden Storm Commencement (SSC). The Dst index ultimately reached a minimum of \(-\)333 nT, signifying extreme geomagnetic disturbance. Figure 3: Variations of the interplanetary and geophysical parameters during 5–14 October 2024. From the top to bottom panels are (**a**) F10.7, (**b**) solar wind velocity, (**c**) solar wind density, (**d**) IMF By and Bz, (**e**) AE index, (**f**) Kp index, and (**g**) Dst index. These parameters are provided by OMNIWeb ([[https://omniweb.gsfc.nasa.gov/](https://omniweb.gsfc.nasa.gov/)]([https://omniweb.gsfc.nasa.gov/](https://omniweb.gsfc.nasa.gov/)), accessed on 13 April 2025). As mentioned in the Introduction, satellites in orbit are continuously subjected to atmospheric drag, leading to orbital decay. To maintain their orbital altitude, satellites typically perform regular maneuvers. During geomagnetic storms, thermospheric expansion causes a sharp increase in atmospheric density, accelerating orbital decay and potentially necessitating additional maneuvers. Using Shell 1 data as an example, Figure 4 presents the maneuver detection statistics for Starlink satellites in Shell 1. The results for each orbital plane are shown in Figure 4a, where lower-numbered planes are positioned higher in the figure to maintain feature continuity. The total number of maneuvering satellites across all orbital planes in Shell 1 is shown in Figure 4b. Figure 4a reveals distinct dark blue lines of high maneuver counts spanning all planes, indicating that Starlink satellites follow a predefined maneuver strategy, sequentially maneuvering plane by plane. We refer to these as routine maneuvers. In contrast, irregularly distributed maneuvers (with no clear pattern in timing or orbital plane) are classified as special maneuvers, which we speculate are performed by SpaceX to adjust specific satellite orbital parameters or execute emergency collision avoidance. The statistical results show that, under normal conditions, routine maneuvers begin with satellites in Plane 37 and end with those in Plane 36, occurring approximately every two days. Between two-day routine maneuvers, similar patterns are also observed. For instance, prior to 8 October, Planes 1-36 executed large-scale maneuvers, while, on 9 and 11 October, maneuvers covering all planes occurred shortly after the previous routine maneuvers. Correlating these events with Dst index variations, we can associate them with geomagnetic storms.