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Investigation on the variability of the geomagnetic daily current during sudden stratospheric warmings

Citation

Owolabi, C and Lei, J and Bolaji, OS and Jimoh, O and Ruan, H and Li, N and Niu, X and Yoshikawa, A, Investigation on the variability of the geomagnetic daily current during sudden stratospheric warmings, Journal of Geophysical Research: Space Physics, 124, (7) pp. 6156-6172. ISSN 2169-9380 (2019) [Refereed Article]


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Copyright Statement

Copyright 2019 American Geophysical Union

DOI: doi:10.1029/2019JA026667

Abstract

The magnetic field records of the magnetometer networks in the American, East Asian-Australian, and European-African sectors were employed in this present work. We used them to investigate equatorial electrojet (EEJ), counter electrojet (CEJ), tidal variability in EEJ strength and ionospheric current during the 2005/2006 and 2008/2009 sudden stratospheric warming (SSW) events. In addition to the well-investigated tidal variability in EEJ strength over the American and East Asian sectors, we investigated that of the African sector for the first time. Interestingly, the tidal components in EEJ strength during both SSW events clearly exhibit marked longitudinal differences with high, moderate, and low amplitudes in the American, East Asian, and African sectors, respectively. An exception found around day 71 in the African sector after the 2008/2009 SSW event had higher solar diurnal tidal component as compared to that of the Asian sector. Over the American sector, solar and lunar semidiurnal tides were strongly associated with CEJ current during both SSW events, whereas at the African and East Asian sectors such variabilities are not evident. A solar diurnal tidal component was strongly related to a reduction in the EEJ strength over the East Asian sector. In addition, a prolonged period of CEJ occurrence that begins during the SSW precondition and ends when the SSW was evolving characterized the African sector during both SSW events. There is a steady shift in phase at later hours when both SSW events are evolving.

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:139980
Year Published:2019
Web of Science® Times Cited:5
Deposited By:Physics
Deposited On:2020-07-21
Last Modified:2020-08-19
Downloads:3 View Download Statistics

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