Storm Time Total Electron Content Modeling Over African Low-Latitude and Midlatitude Regions

Abstract

This paper presents storm time total electron content (TEC) modeling results based on artificial neural networks, for both low-latitude and midlatitude African regions. The developed storm time TEC models were based on Global Positioning System (GPS) observations from GPS receiver stations selected in low latitude, Northern and Southern hemisphere midlatitude regions of the African sector. GPS data selection was based on a storm criterion of Dst≤ −50 nT and storm data sets used to develop the models were within the periods 2001–2015, 2000–2015, and 1998–2015, for African low latitude, Northern and Southern Hemisphere midlatitude regions, respectively. For the first time in storm time TEC modeling, the meridional wind velocity was introduced as an additional input to the well-known TEC modeling inputs (diurnal variation, seasonal variation, solar activity, and geomagnetic activity representations) to take into account the effect of neutral winds in moving ionization within the ionosphere along the magnetic field lines. Results showed that the use of meridional wind as an additional input leads to overall percentage improvements of about 5%, 10%, and 5% for the low-latitude, Northern and Southern Hemisphere midlatitude regions, respectively. High-latitude storm-induced winds and the interhemispheric blows of the meridional winds from summer to winter hemisphere may be associated with these improvements.