Latitudinal variation of the ionosphere in the African sector using GPS TEC data

Abstract

Total electron content (TEC) measured by the network of receivers from Global Navigation Satellite Systems (GNSS) at 18 stations in the year 2011 was used to study the ionospheric variations. The stations are chosen along a longitudinal range (27-40° E) covering all the latitudes of the African sector. The latitudinal variations investigated include: annual, seasonal, diurnal, and day-to-day. The annual and seasonal results presented an equinoctial asymmetry in all stations and a winter anomaly during the solstice months for the stations near the equator. The diurnal variation in the same equatorial stations exhibited features like noontime bite-out, night-time enhancements and high day-to-day TEC variability especially in September. The day-to-day variability was larger in the station around geomagnetic latitude 16° S (dodm). Latitudinally, the TEC recorded keep on decreasing as you ascend the latitudes of both hemispheres showing a maximum around the geomagnetic equator with a trough between geomagnetic and geographic equators.