| DOI: | 10.1002/2016GL068039
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| 论文题名: | Response of northern winter polar cap to auroral substorms |
| 作者: | Liou K.; Sotirelis T.
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| 刊名: | Geophysical Research Letters
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| ISSN: | 0094-9022
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| EISSN: | 1944-8753
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| 出版年: | 2016
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| 卷: | 43, 期:9 | | 起始页码: | 4098
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| 结束页码: | 4105
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| 语种: | 英语
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| 英文关键词: | auroral substorm
; onset timing
; polar cap area
; polar UVI
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| Scopus关键词: | Unloading
; Auroral images
; High resolution
; Night-side polar cap
; Onset timing
; Polar cap
; Polar UVI
; Substorm expansion
; Substorms
; Plasma theory
; atmospheric electricity
; aurora
; deflation
; instrumentation
; Northern Hemisphere
; storm
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| 英文摘要: | The three-phase substorm sequence has been generally accepted and is often tied to the Dungey cycle. Although previous studies have mostly agreed on the increase and decrease in the polar cap area during an episode of substorm, there are disparate views on when the polar cap starts to contract relative to substorm onset. Here we address this conflict using high-resolution (~1-3 min) snapshot global auroral images from the ultraviolet imager on board the Polar spacecraft. On the basis of 28 auroral substorm events, all observed in the Northern Hemispheric winter, it is found that the polar cap inflated prior to onset in all events and it attained the largest area ~6 min prior to the substorm expansion phase onset, while the dayside polar cap area remained steady around the onset. The onset of nightside polar cap deflation is found to be attributed to intensifications of aurora on the poleward edge of the nightside oval, mostly in the midnight sector. Although this result supports the loading-unloading and reconnection substorm models, it is not clear if the initial polar cap deflation and the substorm expansion are parts of the same process. © 2016. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84966444574&doi=10.1002%2f2016GL068039&partnerID=40&md5=753e05e99643f5716ff2d1639ed760ae
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/9985
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| Appears in Collections: | 科学计划与规划
气候变化与战略
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作者单位: | Johns Hopkins University, Applied Physics Laboratory, Laurel, MD, United States
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| Recommended Citation: | |
Liou K.,Sotirelis T.. Response of northern winter polar cap to auroral substorms[J]. Geophysical Research Letters,2016-01-01,43(9).
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