Total Electron Content response to Geomagnetic Activity over Five African Equatorial and Low Latitude Stations

An investigation on the response of the ionosphere to three geomagnetic storms (two strong (Dst<-100 nT, and one moderate (Dst<-50 nT) of March 17-18.June 01, and December 7-8,, 2013 has been made.The study was carried out using the total electron content (TEC) data derived from the global positioning system (GPS) receivers located at five African equatorial and low latitude stations (Toro, Mbar, Mal2, Dodm and Zamb).The stations fall between geomagnetic Latitude 0.95 0 S and 26.25 0 S and are located in the southern hemisphere.The quiet time analyses of the TEC profiles for each stations were first of all investigated using the averaged values of TEC for the five quietest days of the months in which the geomagnetic storms occurred.Results from the study show a significant variation of TEC during the disturbed days compared to those of the quiet time period.The geomagnetic storm results show prominent cases of day and night time enhancement in TEC during the main and recovery phases of the storms with percentage deviations ranging from 30 -112 %.Furthermore, a well -defined double peak of ionization was observed during the main phase of strong geomagnetic storm of June 01, 2013 event particularly at Dodm (16.10 0 S) and Zamb (26.25 0 S).The enhancement in TEC is indicative of the effect of the prompt penetration electric fields and the enhanced equatorial fountain.