Storm‐Time Ionospheric Response Over Iran to the 10 May 2024 Extreme Geomagnetic Event: Impacts of EIA Intensification and Auroral‐Driven LSTIDs

The present paper provides first study of ionospheric response to major storm over Iran. We analyze the ionospheric response over Iran to the extreme space‐weather event of 10 May 2024 using a dense network of ∼34 GNSS receivers concentrated in northern and western Iran. We produce spatially interpolated total electron content (TEC) maps and quantify temporal evolution, extremes (local maxima and minima), and the spatial extent of perturbations during 9–13 May 2024. The TEC time series on interpolated grids are compared with geomagnetic indices ( K p and D st ) to isolate storm‐driven variations from background variability. Ground magnetometer data from the Magnetic Data Acquisition System station in Sri Lanka are used to assess equatorial electrojet (EEJ) and equatorial ionization anomaly (EIA) influences on regional TEC, testing whether transient EEJ/EIA strengthening and poleward expansion of the northern EIA crest contributed to positive and negative storms over southern Iran. We then investigate large‐scale traveling ionospheric disturbances (LSTIDs) observed on 10–11 May, computing propagation directions, phase velocities, and wavelengths via keogram analysis, cross‐correlation of station pairs, and 2‐D differential‐TEC maps. The derived speeds are validated against global differential TEC from the Madrigal database. Results show a rapid storm‐time TEC enhancement coincident with K p / D st excursions and pronounced EEJ intensification, followed by the onset of multi‐front LSTIDs propagating predominantly southwestward with phase speeds consistent with gravity‐wave excitation by auroral forcing and/or sudden impulse drivers. Our study demonstrates how regional GNSS arrays combined with magnetometer and global dTEC products provide complementary constraints on storm‐time dynamics of the mid‐latitude ionosphere over Iran.