Multi-instrument analysis of F-region ionospheric irregularities suppression over South America during the November 3, 2021, geomagnetic storm

Equatorial ionospheric irregularities have the potential to disrupt radio communications and satellite-based navigation. The influence of geomagnetic storms on these disturbances remains not fully understood, particularly in how they may initiate or inhibit the irregularities (also called Equatorial Plasma Bubbles, EPBs). Enhanced predictive capabilities require comprehensive studies of the ionosphere’s behavior, especially within the equatorial ionization anomaly (EIA) zone, where such irregularities are more pronounced. This study examines the effect of the November 3, 2021, geomagnetic storm on equatorial ionospheric irregularities in the F region over South America. We used data from multiple instruments, including GPS, GOLD, ICON, ionosondes, SuperDARN, and AMPERE, to analyze the role of the storm-time electric fields in the day-to-day dynamics of EPBs. We found that irregularities were suppressed during the storm’s main and recovery phases. Our results suggest that the inhibition of ionospheric irregularities in the F region may be associated with a combination of westward under-shielding penetration electric field and disturbance dynamo electric fields. The present study may contribute to advancing our understanding of the ionospheric response to geomagnetic storms and to develop better predictive models for space weather impacts.