Performance evaluation of AfriTEC model during quiet and disturbed time over East African sector

Abstract

This study evaluates the performance of the African Regional Ionospheric Total Electron Content (AfriTEC) model across varying solar activity levels in the East African sector. Focusing on the solar maximum year of 2014 and the solar minimum year of 2009, the analysis utilizes TEC data derived from GPS receivers at six IGS stations. The study compares the AfriTEC model outputs with the corresponding GPS-TEC data, demonstrating a consistency between the datasets. The diurnal variation pattern of model shows an underestimation at daytime than nighttime can be visible at all days. Observed vertical TEC shows best performance at morning and afternoon, the ionosphere is most stable and poor at evening and pre-down. The seasonal variation shows that with maximum values at March equinox and December solstice months and minimum during June solstice and September equinox months. The model best during equinoxes compared to solstices more uniform ionization and stable ionospheric condition. The monthly variation of model accuracy show that during the solar maximum year, the model exhibited poor performance, with a peak error of 14 recorded in DODM during disturbed times and a minimum error of 2 in ADIS during the same conditions. In contrast, during the solar minimum year, the model’s accuracy improved significantly, showing a minimum error of 1 at MOIU during quiet times and a maximum error of 5.5 at MBAR during disturbed times. We emphasize that the decision from this paper would complement in the model performance at various geophysical conditions over the equatorial and low latitude sector like East African region.