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Excursions of interhemispheric field-aligned currents in Africa

Citation

Owolabi, OP and Bolaji, OS and Adeniyi, JO and Oyeyemi, EO and Rabiu, AB and Habarulema, JB, Excursions of interhemispheric field-aligned currents in Africa, Journal of Geophysical Research: Space Physics, 123, (7) pp. 6042-6053. ISSN 2169-9380 (2018) [Refereed Article]

Copyright Statement

Copyright 2018 American Geophysical Union

DOI: doi:10.1029/2017JA025083

Abstract

The interhemispheric field‐aligned currents (IHFACs) are the most evident currents connecting the solar quiet (Sq) current systems in the Northern and Southern Hemispheres. Understanding these coupling currents has practical importance for space weather forecast of the magnetosphere‐ionosphere interactions and their potential impacts on low‐orbiting spacecraft. In this paper, we have examined digital magnetic records from September 2008 to August 2009 at nine Magnetic Data Acquisition System (MAGDAS) stations in order to uniquely determine the variability of IHFACs in terms of their excursions in the African sector. By excursions, we mean the direction in which the IHFACs are moving as a function of local time or latitude. Different from theoretical prediction, we found prominent positive IHFACs around dusk in February and March equinox. A novel feature of this study is the semidiurnal variation control of the coupling between the Northern and Southern Hemispheres. In addition, we found terdiurnal variation in September with their associated strong diurnal variations from October through December. Quite unexpectedly, in January, a significant latitudinal depletion in the intensities of IHFACs was observed from dawn to dusk, compared to any other months under investigation, accompanied with a marked reduction of the prominent diurnal variations at the magnetic equator (Addis Ababa, AAB). The fact that the excursions of IHFACs in January experience an unusual retardation with respect to their in

Item Details

Item Type:Refereed Article
Research Division:Physical Sciences
Research Group:Space sciences
Research Field:Mesospheric, thermospheric, ionospheric and magnetospheric physics
Objective Division:Environmental Management
Objective Group:Air quality, atmosphere and weather
Objective Field:Atmospheric processes and dynamics
UTAS Author:Bolaji, OS (Dr Olawale Bolaji)
ID Code:139974
Year Published:2018
Web of Science® Times Cited:4
Deposited By:Physics
Deposited On:2020-07-21
Last Modified:2020-08-19
Downloads:0

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