TitleEffect of moderate geomagnetic storms on equatorial plasma bubbles over eastern Africa in the year 2012: Evolution and electrodynamics
Publication TypeJournal Article
Year of Publication2020
AuthorsGiday, NMezgebe, Katamzi-Joseph, ZT, Stoneback, R
JournalAdvances in Space Research
Volume65
Issue7
Pagination1701 - 1713
Date Published04/2020
ISSN02731177
KeywordsC/NOFS; Equatorial electrojets; equatorial plasma bubbles
Abstract

Equatorial plasma bubbles (EPBs) are common features of the equatorial and low-latitude ionosphere and are known to cause radio wave scintillation which leads to the degradation of communication and navigation systems. Although these structures have been studied for decades, a full understanding of their evolution and dynamics remains important for space weather mitigation purposes. In this study, we present cases of EPBs occurrences around April and July 2012 geomagnetic storm periods over the African equatorial sector. The EPBs were observed from the Communications/Navigation Outage Forecasting System (C/NOFS) and generally correlated well to the ionospheric irregularities observed from the Global Positioning System total electron content (GPS-TEC) measurements (rate of TEC change, ROT). This study revealed that the evolution of the EPBs during moderate storms is controlled by the strength of the daytime equatorial electrojet (EEJ) currents regardless of the strength of the equatorial ionization anomaly (EIA), the latter is observed during the July storm case in particular. These effects were more evident during the main and part of the early recovery phases of the geomagnetic storm days considered. However, the evening hours TEC gradients between regions of the magnetic equator and ionization crests also played roles in the existence of ionospheric irregularities.

URLhttps://www.sciencedirect.com/science/article/pii/S0273117720300314
DOI10.1016/j.asr.2020.01.013
Short TitleAdvances in Space Research


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