Storm‐Time Longitudinal Behavior of the Low‐Latitude Ionosphere in the American and African Sectors During the 23–24 March 2023 Geomagnetic Disturbances

Abstract This study investigates the storm‐time behavior of the low‐latitude ionosphere in American and African sectors during geomagnetic disturbances in March 2023, with particular emphasis on the storm of 23–24 March 2023. Using GPS‐derived Vertical Total Electron Content (VTEC) observations across the American (75°W) and African (38°E) sectors, we analyzed the evolution of Equatorial Ionization Anomaly (EIA) structures and estimated the Rate of change of TEC Index (ROTI) to assess ionospheric irregularities. The results reveal distinct longitudinal responses during the storm's main phase: the American sector exhibited negative storm effects, equatorward shift in EIA crests, and pronounced irregularity development, driven primarily by enhanced Prompt Penetration Electric Fields (PPEFs), and inferred vertical E × B drifts. Conversely, the African sector showed positive storm responses, characterized by stable EIA crest positions and distinct hemispheric asymmetries in TEC, which may be attributed to weaker electrodynamic forcing. These findings emphasize the importance of longitudinal and hemispheric variability in shaping low‐latitude ionospheric dynamics and highlight the distinct electrodynamic environments characterizing the American and African sectors.