Large-Scale Traveling Ionospheric Disturbances Over North America and Europe During the May 2024 Extreme Geomagnetic Storm

This study investigates the large-scale ionospheric traveling disturbances (LSTIDs) over North America and Europe associated with the intense geomagnetic storm in May 2024, utilizing total electron content (TEC) data derived from ground-based Global Navigation Satellite System (GNSS) stations. The findings reveal that the observed LSTIDs in both regions exhibited an unusually prolonged duration, lasting for over 10 h from 17:00 UT on May 10 to 03:30 UT on May 11, 2024. This extended duration may be attributed to the continuous triggering of LSTIDs by auroral energy input during the geomagnetic storm. Additionally, significant differences in propagation characteristics, including velocities, azimuths, wavelengths, and traveling distances of LSTIDs, were observed between the two regions. These disparities in LSTID parameters are likely due to variations in the magnitude of energy input in the polar regions and local time differences in North America (14:00 LT) and Europe (19:00 LT), which cause diurnal electron-density contrast to influence LSTID propagation.