Response of the African Equatorial-Low Latitudes Ionosphere to 17 March 2013 and 01 June 2013 Geomagnetic Storms

Abstract

Response of the equatorial-low latitude ionosphere to the moderate storms of 17 March 2013 (Dst min=130 nT) and 1 June, 2013 (Dst min=137 nT) has been investigated using GPT-TEC observations in the African sector. The result shows significant response of the GPS-TEC to the two magnetic storm events particularly during the main and recovery phases of the storm. Series of negative and positive responses were observed in the two magnetic storms. The study reveals that for both magnetic storms, the occurrence of SSC associated with northward turning of some magnetic and interplanetary parameters mostly do not produce any significant deviation between the storm-time and mean quiet-time TEC at the equatorial-low latitude around (06:00-11:00) UT hrs. For the 1 June magnetic storm, negative storm-time effect were mostly observed around (06:00-11:00) UT hrs across all the latitudes during the main and recovery phases of the storm. Similar variations are mostly observed during the main and recovery phases of the magnetic storms. However, series of negative and positive storm-time effects were observed in the two magnetic storms. During the main phase, both storms exhibit faint positive storm-time effect around (12:00-14:00) UT hrs across most of the latitudes. During the recovery phase, a faint positive storm-time effect are observed around (06:00-11:00) UT hrs in most latitudes during the March magnetic storm and reverse is the case for the June storm event. The main phase negative storm-time are consequences of weaker PPEF and negative storm-time effect during the recovery phase is a strong evidence of predominance of ionospheric disturbance dynamo electric field (DDEF) suppressing the fountain effect.

Keywords: Ionosphere, Geomagnetic field, electric field, magnetic storm

DOI: 10.7176/APTA/89-04

Publication date:October 31^st 2025