Characterizing the Role of Storm-Time High-Latitude Ionospheric Structures in GPS Position Accuracy in Antarctica: May 2024 Storm

This study investigates the impact of high-latitude ionospheric irregularities on global positioning system (GPS) position accuracy during the 10–11 May 2024 geomagnetic storm. Using data from ground-based GPS receivers and an all-sky camera in Antarctica, we examined evolution of GPS vertical total electron content, phase fluctuations, and precise point positioning (PPP) errors. Results reveal that auroral precipitation associated with the coronal mass ejection shock induced significant GPS phase fluctuations and positioning errors in the dayside cusp region. Tongues of ionization (TOIs) had the largest and most sustained impact on signal disruptions and degraded position accuracy, with a peak position error reaching 28 m. Furthermore, dawnside auroral activity during the substorms and poleward boundary intensifications (PBIs) caused localized disturbances in the auroral oval. Despite sufficient satellite visibility, these irregularities significantly compromised GPS positioning performance.