Ionospheric irregularities during disturbed geomagnetic conditions over Argentinian EIA region

Ionospheric irregularities can severely degrade radio communication and navigation systems. Geomagnetic storms may affect the generation of these in a way that is not yet fully understood. To improve forecasting this phenomenon, we need to study ionosphere different regions world, particular equatorial ionization anomaly (EIA) where are usually more intense. This analyses effect geomagnetic on ionospheric irregularities. We examined occurrence at southern crest EIA Argentina (Tucumán, 26.9°S, 294.6°E, dip latitude 15.5°S) during three intense one moderate storm solar sources, between 2015 2018. used data from an ionosonde, Global Positioning System receiver magnetometers. Ionogram spread-F, F-layer bottom side (h'F), critical frequency F2-layer (foF2), rate TEC index S4 scintillation were analysed. The show present as range spread-F fluctuations storm: 27 May 2017 (a coronal mass ejection CME-driven occurred local winter), absent other events. suggest eastward disturbance dynamo electric field over-shielding prompt penetration fields create favourable conditions for developing irregularities, whereas westward time might inhibit growth considered. During co-rotating interaction region CIR-driven storms, be associated with non-occurrence