Title: Effects of full and partial halo geomagnetic storms on an East African low latitude station

Abstract

Using the RINEX formatted TEC data from the global positioning system (GPS), we analyzed the impact of full and partial halo CMEs induced geomagnetic storms on ADIS (9.02 oN, 38.44 oE), an east African low latitude ionospheric station located in Addis Ababa, Ethiopia. The storms of 23rd June 2015 and 1st January 2016 which occurred in the solstice months of summer and winter respectively were quantified using Dst indices obtained from WDC Kyoto, Japan. The result showed contrasting storm time ionospheric responses to the two storm events which depended mainly on the timing of the storms occurrences, the onset of storm sudden commencement, and proton density (PD) peaks. Furthermore, the magnitudes of the PD determine the level of energy input during magnetic reconnections and subsequent formations of sub-storms and storms. This study points to the fact that the behavior of the African equatorial/low latitude is very much dependent on the timing of the geomagnetic storms. While seasonal effects are seen in the overall ionospheric responses at all the stages of the storm events, the storm-time responses depended on the time of the day the storm occurred and the orientation of the accompanying magnetic and electric fields. The result of this study complements a global effort towards understanding the complexities of ionospheric variability within the African low and equatorial ionosphere, especially at disturbed times.