Geomagnetic field H, Z and electromagnetic induction features of coronal mass ejections in association with geomagnetic storm at African longitudes

The largest geomagnetic disturbance caused by coronal mass ejection (CME) of solar cycle 24 recorded on both 17 March and 22 June 2015 with minimum Dst values of −223 and −195 nT respectively was investigated. This study examine the effect of coronal mass ejection (CME) on Earth geomagnetic field which include the time derivatives of horizontal (H) and vertical (Z) components of the geomagnetic field and the rate of induction ΔZ/ΔH at African longitudes (AAE, MBO, HBK, HER and TAM). The results demonstrated enhancement of dH/dt and dZ/dt at the daytime over the equatorial zone (AAE and MBO) and mid latitudes (TAM, HER and HBK) on 17 March 2015. Nighttime enhancement was observed on 22 June 2015 over the equatorial zones and mid-latitudes. Wavelet spectrum approach is used to investigate ΔZ/ΔH variation observed at AAE, MBO, HBK, HER, and TAM. The CME may have an influence on time derivatives of geomagnetic field H, Z and electromagnetic induction at the African longitudes which might be associated with perturbations in electric fields and currents in the equatorial and low latitude magnetic field linked with the changes in magnetospheric convection.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author