Variation of the foF2 parameter during fluctuating activity: Prediction with IRI-2012 compared to measured data from Ouagadougou inosonde station during solar cycles 21 and 22

Abstract

In this paper, we review on diurnal variation s of the foF2 ionospheric parameter predicted by the IRI- 2012 model, and data from Ouagadougou ionosonde station located in the crest of the Equatorial Anomaly (Lat: 12.5°N; Long: 358.5°E, dip: 1.43°) during fluctuating geomagnetic activity conditions for the solar cycles 21 and 22. Our investigations are focused on the electrodynamic aspects, the influence of the ionospheric electric currents as well as the variations of the hourly values given by model and experimental measurements. A comparative study pointed out that the IRI-2012 model, through its URSI and CCIR subroutines, gives a good prediction of the critical frequency of the F2 layer between 0700 TL and 0000 TL In addition, IRI-2012 tries to reproduce, as best as possible, the vertical drift E x B during minimum, decreasing phase, winter, and autumn. However, there is no effect of drift during the other seasons and solar cycle phases. A last, the model does not take into account the PRE phenomenon observed in autumn and the influence of the equatorial electrojet in this ionospheric zone.