简介：ThepresentstudyinvestigatesthechangesinTEC(totalelectroncontent)andionosphericscintillationindex(S4)inferredfromtheGNSSdatarecordedattheSCINDAstationofAbidjan(Latitude=5.34°N,Longitude=3.90°W)duringandafterasolarflare.Inthecourseof2014,ayearofhighsolaractivity,three(3)casesofextreme(X1.66)andmoderate(M6.23andM2.13)solarflaresrecordedinthemonthsofSeptemberandDecembereffectsontheionospherehavebeenstudiedusingtheXrayfluxes,themagneticparameters(Vx,Bz,Dst),theionosphericscintillationindexS4andTECanditsROT(timerateofchange).TheROTexhibitsaprominentpeakbetweenten(10)andtwelve(12)minutesaftertheoccurrenceofthemaximumpeakofthetimerateofchangeoftheX-rayfluxemittedduringtheflare.TheROTmaximumvalueoccurssimultaneouslywithanenhancementoftheS4index.DeferredperturbationsofthesolarflareontheTECintheSCINDAstationofAbidjanoccurwithin42to54hoursafteranM-classsolarflareandwithin46to58hoursfollowinganX-Classsolarflare.Themagneticstormsresultedfromtheseflaresshowanincrementof20%onVTECobservedwhencomparedtotheaverageVTEC()computedfromthemostfive(5)quietestdaysoftheselectedmonths.