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This study’s objective is to better specify the rare occurrence of super equatorial plasma bubbles in particular to the European longitude sector, detailing their spatio-temporal evolution, and better understanding pre-conditions for their development. Our comprehensive multi-instrument analysis combined ground-based and space observations from GNSS, ionosondes, and several satellite missions (COSMIC-2, GOLD, Swarm). We have investigated the ionospheric response to the 23–24 April 2023 severe geomagnetic storm and have shown the formation of super plasma bubbles expanding from equatorial latitudes to middle latitudes in the European/African sector during the main phase of the storm. Formation of these super bubbles was associated with storm-induced prompt penetration electric fields. We found that the area affected by the formation of numerous plasma bubbles covered more than 5000 km ranging from 30°W to 30°E in the Atlantic/African sector. The bubbles also had an impressive north-south extension, reaching as far poleward as ~30°–35° latitude in both hemispheres. After 20 UT on 23 April 2023, the zone with equatorial ionospheric irregularities reached Northern Africa, the Iberian Peninsula (Spain, Portugal) and the Mediterranean Sea in southern Europe, including areas of the Canary Islands (Spain) and the Azores and Madeira Islands (Portugal) in the Atlantic Ocean. The ionospheric irregularities persisted for 5–6 h and began to fade after ~01 UT on 24 April 2023. COSMIC-2 scintillation measurements showed intense amplitude scintillations (S4 above 0.8) across this entire region, indicating presence of small-scale ionospheric irregularities inside the extended plasma bubbles. During this storm, EGNOS (European Geostationary Navigation Overlay Service) experienced degraded performance, with significant navigation errors recorded at its southernmost stations in Northern Africa, Spain, Portugal, and their territories, which were affected by super plasma bubbles. This paper presents conclusive observational evidence showing development of the super plasma bubbles significantly expanding into the southern Europe and northern Africa region under geomagnetically disturbed conditions in April 2023. 

Using the high-rate phase and amplitude scintillation data from FORMOSA7/COSMIC two mission and back-propagation method, we geolocate plasma irregularities that cause scintillations. The results of geolocation are compared with the NASA GOLD UV image data of plasma bubbles. The root mean square of the zonal difference between estimated locations of plasma irregularities and plasma bubbles are about 1.5° and for single intersection cases 0.5° in the magnetic longitude. The geolocation data provide more accurate scintillation location around the globe compared to assigning to the tangent point and is valuable space weather product, which will be routinely available for public use. 

Abstract The space weather event on 10–11 May 2024 was a high‐impact geomagnetic storm, resulting in a SYM‐H index decrease to −518 nT, the lowest level registered in several decades. We investigated the response of the Earth's ionosphere during the main phase of this storm using a comprehensive data set of ionospheric observations (in situ plasma density and/or Total Electron Content (TEC)) from twenty Low‐Earth‐Orbit satellites such as COSMIC‐2, Swarm, GRACE‐FO, Spire, DMSP, and Jason‐3, orbiting at altitudes between 320 and 1,330 km. We found that ionospheric response followed a classical development pattern with the largest positive effects occurred at low and middle latitudes in daytime and evening sectors, associated with significant intensification of the Equatorial Ionization Anomaly (EIA) by the super fountain effect. The greatest effects occurred in the Pacific and American longitudinal sectors, which were in daylight, between 19 and 24 UT on 10 May 2024. This time overlaps with a period of steady southward IMF Bz and favorable conditions for long‐lasting penetration electric fields. The EIA crest‐to‐crest separation expanded to 40–60° in latitude with the largest poleward excursion of the crest to ∼27° magnetic latitude. The extreme EIA expansion with crest separation up to 60° in latitude along with a giant plasma bite‐out near the magnetic equator were observed in the dusk/evening sector over South America. The ground‐based TEC showed an enhancement up to ∼200 TECU, while satellites detected an increase in topside TEC up to ∼100–155 TECU, indicating key contribution of the topside ionosphere into the ground‐based TEC.