Multi‐Source Observations of North American Mid‐Latitude Ionospheric Disturbances During the May 2024 Superstorm: Impacts on RTK Positioning

This study thoroughly investigates the propagation characteristics of traveling ionospheric disturbances (TIDs) and the ionospheric response to the 10–11 May 2024 geomagnetic storm over mid‐latitude North America using ground‐based global navigation satellite system (GNSS) data and Swarm satellite data. During the storm's main phase, significant positive ionospheric storms were observed in the western and eastern sectors of mid‐latitude North America, with vertical total electron content enhancements exceeding 150% and 100%, respectively. Our analysis combining ground‐based GNSS and Swarm satellite observations identified seven large‐scale traveling ionospheric disturbance wavefronts propagating along the magnetic meridian plane at speeds of 729–980 m/s, with periods of 33–80 min and wavelengths spanning 1,600–2,700 km. Additionally, from 21:30 UT on 10 May 2024 to around 00 UT on 11 May 2024, the eastern sector observed medium‐scale traveling ionospheric disturbance propagating in a northwest‐southeast direction and southwestward. These TIDs can affect the performance of mid‐latitude GNSS positioning accuracy. By studying the relationship between total electron content (TEC) gradient and real‐time kinematic (RTK) positioning errors, it was found that ionospheric gradients (single‐and double‐difference detrended TEC > 1.5 TECU) reduced the accuracy of RTK positioning, with positioning errors exceeding 1 m in some receivers. These observations highlight the critical challenges faced by ionospheric modeling and safety‐critical navigation systems during extreme space weather events. There is a need to improve mitigation frameworks by incorporating the dynamics of the coupled magnetosphere‐ionosphere‐thermosphere system.