Significant mid- and low-latitude ionospheric disturbances characterized by dynamic EIA, EPBs, and SED variations during the 13-14 March 2022 geomagnetic storm

This work investigates mid-and low-latitude ionospheric disturbances over the American sector during a moderate but geo-effective geomagnetic storm on 13-14 March 2022 (pi-Day storm), using ground-based Global Navigation Satellite System total electron content data, ionosonde observations, and space-borne measurements from the Global-scale Observations of Limb and Disk (GOLD), Swarm, the Defense Meteorological Satellite Program (DMSP), and the Ionospheric Connection Explorer (ICON) satellites.

Our results show that this modest but geo-effective storm created a number of large ionospheric disturbances, especially the dynamic multi-scale electron density gradient features in the storm main phase as follows: (a) The low-latitude equatorial ionization anomaly (EIA) exhibited a dramatic storm-time deformation and reformation, where the EIA crests evolved into a bright equatorial band for 1-2 hr and then quickly separated back into the typical double-crest structure with a broad crest width and deep equatorial trough.