The ionosphere around the Equatorial ionization Anomaly (EIA) region exhibits a complex dynamic and responds markedly to the solar-magnetospheric energy and momentum. In this paper, the hourly response of the EIA structure in the Africa to St. Patrick’s Day storms of March 2013 and 2015 is investigated using data obtained from a chain of GPS receivers located in the African region. The TEC variations were characterized based on the convective magnetospheric dynamo fields, the neutral wind circulation, and zonal electric fields. Generally, the result indicates that the TEC variations were consistent with the different directions of the interplanetary fields during the different phases of the storms. We observed reverse EIA structures in the main phase of the storm of March 2015, suggests to be related to the intense PPEF and strong equatorward wind which imposed westward zonal electric field at the equator. Similar equatorial peak observed during the recovery phase is associated to DDEF, poleward wind and plasma convergence. Furthermore, TEC variations also indicate hemispheric asymmetries during the storms. During the main phase, the TEC is more enhanced in the northern hemisphere during the storm of March 2013, this was reversed during March 2015. We observed equatorial peak during SSC period of the storm of March 2013, while EIA structures are generally weak in March 2015 event. This may posit that ionospheric pre-storm behaviour is better understood when the IMF-Bz and electric field are weak. The observed distinctive response avowed the peculiarity in the electrodynamics intricacy in the Africa sector.

The F2-layer propagation factor M(3000)F2 is important to ionospheric studies owning to its use in HF radio communication/ionospheric modelling. This study focused on reducing the shortcomings in the use of M(3000)F2 IRI-model for obtaining hmF2, especially in the African equatorial region, by obtaining an empirical ‘constructed model’ (M(3000)F2CM ) using the Korhogo (geomag. lat. 1.26°S, long. 67.38°E, dip.-0.670S) data (M(3000)F2KOR). The data spans 8 years (1993-2000) under magnetically quiet conditions (Ap< 20nT). The Regression method technique was used in obtaining the M(3000)F2CM. The M(3000)F2KOR results revealed that low solar activity (LSA) years have predominantly higher magnitudes than high solar activities (HSA) for all seasons, revealing solar activity dependence. The regression coefficient (R2) for the M(3000)F2KOR versus F10.7 relationship was stronger during the solstices. The associated diurnal equations obtained for all seasons from the regression plot of the M(3000)F2KOR-F10.7 relationship were used to obtained the constructed model equation given by , which allows the prediction of diurnal, seasonal and solar cycle variation of the M(3000)F2 parameter. M(3000)F2CM predicted well when tested at different solar activities. Generally, M(3000)F2CM performed reasonably well in comparison with the IRI model (M(3000)F2IRI) when validated with Ouagadougou (lat. 0.59°S, long. 71.46°E) observed data - M(3000)F2OUA. The %deviation of M(3000)F2CM versus M(3000)F2OUA during HSA and LSA ranges from -10.8- 5.3/-7.6 - 15.8 for solstices/equinoxes; whereas %deviation of M(3000)F2IRI versus M(3000)F2OUA spans -15.5 - 9.2 and -9.7 - 17.7 in similar order of seasons. These results suggest that the new model has a measure of potential for its use in the equatorial region.