Geomagnetic Storm Effects on LEO Satellite Orbits

Geomagnetic storms can significantly enhance thermospheric neutral density, increasing atmospheric drag and perturbing satellite orbits in low Earth orbit (LEO). Understanding the magnitude of storm-time orbital deviations is important for improving orbit prediction. In this study, we investigate the impact of the 17 March 2015 St. Patrick’s Day geomagnetic storm on LEO satellite orbital dynamics by comparing with quiet-time conditions.
Neutral density fields are calculated from the Whole Atmosphere Community Climate Model with thermosphere–ionosphere extension (WACCM-X). Atmospheric drag is calculated from the relative velocity between the satellite and the background atmosphere, and the resulting drag acceleration is incorporated into the satellite equations of motion to simulate orbital trajectories for the GRACE satellite.
By comparing storm and quiet conditions, we quantify the cumulative orbital perturbations over a one-day period. At an altitude of approximately 500 km, the storm produces an along-track displacement of about 500 m and a radial deviation of 15 m. At lower altitudes near 220 km, representing reentry-like conditions, the perturbations become much larger, reaching 10.5 km in the along-track direction and ~977 m radially.
These results demonstrate that geomagnetic storm–driven thermospheric density enhancements can substantially increase orbital uncertainty, particularly at lower altitudes. The findings highlight the importance of accurately modeling storm-time thermospheric density for reliable orbit prediction and space situational awareness in the increasingly crowded LEO environment.