Akademik Veri Yönetim Sistemi
Journal of Atmospheric and Solar-Terrestrial Physics, cilt.278, ss.1-11, 2026 (Hakemli Dergi)
The Gannon geomagnetic superstorm of May 2024, classified as a G5-level event, significantly disturbed Earth’s magnetosphere and ionosphere. This study examines storm-time ionospheric responses over Europe by integrating Global Navigation Satellite System-derived Total Electron Content (GNSS-derived TEC) parameters (vTEC, ΔTEC, and rTEC) with ground-based geomagnetic field observations, while also considering equatorial features such as the equatorial ionization anomaly (EIA). TEC data from the Centre for Orbit Determination in Europe (CODE) revealed substantial ionospheric restructuring with clear diurnal and latitudinal variability. During the main phase, the nighttime EIA exhibited hemispheric asymmetries, with partial suppression over the African and Atlantic sectors, driven by prompt penetration electric fields (PPEFs) arising from enhanced solar wind–magnetosphere coupling shortly after the storm sudden commencement (SSC) on 10 May. These fields contributed to concurrent TEC reductions of 20 to 25 TECu over Europe. In the early recovery phase, plasma suppression became evident, primarily driven by disturbance dynamo electric fields (DDEFs) and thermospheric composition changes. Daytime TEC depletions exceeding 35 TECu (rTEC < 0.8) persisted for over 18 h between 30 ◦ N and 50 ◦ N, confirming one of the most prolonged negative phases reported at European mid- latitudes. Perturbations in horizontal (H) and vertical (Z) magnetic field components further supported the role of intensified ring current activity and large-scale field-aligned currents (FACs). These findings highlight the dominant electrodynamic drivers, with contributions from thermospheric processes, and underscore the importance of space weather impacts for modern technological systems.