Classification of fast flows in central plasma sheet: Superposed epoch analysis based on THEMIS observations

	Classification of fast flows in central plasma sheet: Superposed epoch analysis based on THEMIS observations
	Li, H.; Wang, C.; Fu, S. Y.
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
	2014
卷号	119 期号:9
ISSN号	2169-9380
通讯作者	Li, H (reprint author), Chinese Acad Sci, Ctr Space Sci & Appl Res, State Key Lab Space Weather, Beijing, Peoples R China.
英文摘要	A statistical survey of 560 fast flows in midnight central plasma sheet is performed based on Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations during its first two tail phases. From superposed epoch analysis, no significant substorm activities are found to be associated with the occurrence of fast flows beyond X = -15 Re. Considering the associations with substorm activities, the fast flows inside of X = -15 Re can be classified into two obvious classes: short duration (< 2.0 min) and long duration (> 4.0 min). Substorm breakups are shown to be more closely correlated to short-duration fast flows. Furthermore, the onset of short-duration fast flows in the dipolarization region (X = -9 to -11 Re) is almost simultaneous with the onset of substorm breakups and dipolarizations. On the other hand, time delays of 2-4 min are both found in the near-Earth region (X = -7 to -9 Re) and in the near-tail region (X = -11 to -15 Re). Assuming that short-duration fast flows are generated by the force imbalance caused by cross-tail current disruption, these features are consistent with the predictions made by the cowling electrojet current loop and the cross-tail current disruption substorm models. In comparison, although more magnetic flux is transported toward Earth for long-duration fast flows, no clear substorm breakup is closely associated with them. The analysis of 2-D ion velocity distribution further shows some differences. For short-duration fast flows, multiple crescent-shaped ion populations are found. However, for long-duration fast flows, there exists only a single crescent-shaped ion population. The difference may be an important signature for distinguishing these two classes of fast flows.
收录类别	SCI
语种	英语
内容类型	期刊论文
源URL	[http://ir.nssc.ac.cn/handle/122/4452]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	Li, H.,Wang, C.,Fu, S. Y.. Classification of fast flows in central plasma sheet: Superposed epoch analysis based on THEMIS observations[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2014,119(9).
APA	Li, H.,Wang, C.,&Fu, S. Y..(2014).Classification of fast flows in central plasma sheet: Superposed epoch analysis based on THEMIS observations.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,119(9).
MLA	Li, H.,et al."Classification of fast flows in central plasma sheet: Superposed epoch analysis based on THEMIS observations".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 119.9(2014).