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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
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: | 9 |
| Deposited By: | Physics |
| Deposited On: | 2020-07-21 |
| Last Modified: | 2020-08-19 |
| Downloads: | 16 View Download Statistics |
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