Characterization of Equatorial Electrojet Current in Africa Sector Using Two Approaches

Abstract

Variations in the Equatorial Electrojet (EEJ) ground strength is estimated in three stations (Addis-Ababa - AAB, Ilorin - ILR and Lagos - LAG) in the Africa sector using MAGDAS data collected from September to December, 2008.  Hourly data of the horizontal magnetic field component was used in the study. The EEJ strength was studied using the observed and model simulation approach to determine the correlation and error in their results. The EEJ strength in the stations was estimated with respect to Maputo located off-dip equator. The maximum strength of magnetic effect of the EEJ at the ground level was observed in AAB with a value of 62.98 nT in December, followed by ILR with 57.51 nT in November, and LAG with 46.76 nT in December. The model simulation presented higher values compared to the observed EEJ values with the highest peak variation of 130 nT in AAB (October), 103 nT in ILR (December), and 79.32 nT in LAG (December). Correlation analysis and Root mean square error (RMSE) was carried between the two methods. Lagos (LAG) presented the best correlation and the least RMSE (0.85 and 0.18) in November, while the least suitable fit was noticed in September with RMSE of 8.15 in Addis Ababa (AAB).