Ionospheric Response on Radio Communication during Different Geomagnetic Conditions at Low-Latitude Stations

The ionospheric response on radio communication during different geomagnetic conditions in low-latitude ionosphere has been studied using ionospheric data. The different geomagnetic conditions of quiet, weak, moderate and intense were considered. The results obtained showed that the two ionospheric parameters of critical frequency of F2 layer (foF2) and total electron content (TEC) vary with time of the day, latitude and geomagnetic conditions. The dependent of foF2 on geomagnetic condition is such that high values of foF2 correspond to high geomagnetic conditions. The highest value of foF2 of 11.0 MHz and 12.0 MHz for Addis Ababa and Cotonou respectively was obtained during the intense geomagnetic condition. This corresponded to the F2-layer peak electron density of 1.40×1010 and 1.79×1010 for Addis Ababa and Cotonou respectively. The various peaks of foF2 in the stations at different geomagnetic conditions reflect the highest frequency at which ionosphere above the stations was reflecting signals at 180o. The observation of uncertainties in form of wave-like perturbations in TEC at the stations revealed the level of ionospheric irregularities developed as a result of storm events. Under suitable conditions, the ionosphere reflects long, medium and short waves, hence very useful for radio communication and navigation.