Total Electron Content Variations at a Low Latitude East African Station and Its Comparison with IRI-2016, IRI-Plas2017 and NeQuick-2 Models during Solar Cycle 24

Abstract

Abstract Ionospheric modelling is one of the most crucial approaches to study the activities of the ionosphere particularly in regions where experimental data are not readily available. This research aims to study the variations of Total Electron Content (TEC) in a low latitude east African station (Addis Ababa) by comparing experimental values of TEC from the Global Positioning System (GPS) with predicted data from IRI-2016, IRI-Plas2017 and NeQuick-2 models during solar cycle 24 using Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) metric analysis approach. An hourly interval profile computed on seasonal basis were used to study the behaviors of TEC. A monthly interval error profile plotted on annual basis was also used to investigate the deviations of the models from the GPS values. This study analyzed TEC data from 2011 to 2017, utilizing 84 months of available data. The results from this study showed TEC have their lowest values during the post-midnight hours (02:00UT) and highest values during the pre-noon hours (11:00UT). We also observed that Equinoxes have high value of TEC than Solstices except during the ascending and maximum phases where seasonal/winter anomalies were recorded. From our statistical analysis, MAE was observed to give error value of ~ 3 TECU (TEC units) lower than the RMSE. Also from this result, we concluded that MAE is a better statistical metric than RMSE. IRI-Plas2017 outperformed IRI-2016 and NeQuick-2 models in predicting TEC values in East Africa during solar cycle 24, with a 71.4% better performance compared to other models.