DOI: 10.1029/2017JA025083
Scopus记录号: 2-s2.0-85052211339
论文题名: Excursions of Interhemispheric Field-Aligned Currents in Africa
作者: Owolabi O.P. ; Bolaji O.S. ; Adeniyi J.O. ; Oyeyemi E.O. ; Rabiu A.B. ; Habarulema J.B.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 7 起始页码: 6042
结束页码: 6053
语种: 英语
英文摘要: 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 intensities points to a relation with the effects of sudden stratospheric warming. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113632
Appears in Collections: 气候减缓与适应
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作者单位: Department of Physics, University of Ilorin, Ilorin, Nigeria; Department of Physics, University of Lagos, Lagos, Nigeria; Department of Physics, University of Tasmania, Hobart, TAS, Australia; Department of Physical Sciences, Landmark University, Omu-Aran, Nigeria; Centre for Atmospheric Research, National Space Research and Development Agency, Anyigba, Nigeria; South African National Space Agency, Hermanus, South Africa; Department of Physics and Electronics, Rhodes University, Grahamstown, South Africa
Recommended Citation:
Owolabi O.P.,Bolaji O.S.,Adeniyi J.O.,et al. Excursions of Interhemispheric Field-Aligned Currents in Africa[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(7)