Mid‐ and High‐Latitude Ionospheric Responses to the Mother's Day Super Geomagnetic Storm of 2024 Using VLF Propagation and Satellite Data

Abstract The geomagnetic storm of 10–11 May 2024 (G5‐level) caused major ionospheric disturbances, providing an opportunity to examine its wide‐ranging effects. This study analyzes ionospheric perturbations over mid‐ and high‐latitude regions using Very Low Frequency (VLF) radio signal observations and TIMED/SABER satellite data in both hemispheres. Significant VLF amplitude anomalies were recorded along five paths (NAA‐BRN, NAA‐ASB, NAA‐KIL, NAA‐St. Johns, and NAA‐Rothera), indicating strong lower ionospheric responses during and after the storm. High‐latitude stations (KIL, Rothera) showed marked signal changes on 11 May, while the mid‐latitude site (ASB) exhibited delayed peaks on 13 May. The associated solar energetic particle (SEP) event produced noticeable VLF fluctuations about 10 min after onset, particularly evident in high‐resolution data. Wavelet analysis confirmed the presence of atmospheric gravity waves (15 s–30 min periods). SABER observations showed enhanced Nitric Oxide (NO) concentrations in the D‐ and E/F‐regions, peaking on 11 May at 85–95 km and 110–130 km altitudes, respectively. These NO increases, caused by energetic particle precipitation, were observed across both hemispheres. Temperature profiles revealed storm‐related warming above 95 km and cooling below 90 km in the Northern Hemisphere, linked to Joule heating, NO‐induced infrared cooling, and vertical transport. The study highlights the value of combining ground‐based VLF and satellite data to understand storm‐time ionospheric dynamics, emphasizing hemispheric asymmetries, delayed responses, and regional variability in space weather effects.