Plasmoid-like structures in multiple X line Hall MHD reconnection

	Plasmoid-like structures in multiple X line Hall MHD reconnection
	Liu, C. X. ; Jin, S. P. ; 魏奉思. ; Lu, Q. M. ; Yang, H. A.
刊名	Journal of Geophysical Research-Space Physics
	2009
卷号	114 页码:A10208
关键词	flux rope geotail observations driven reconnection magnetic-field evolution simulation substorm
ISSN号	0148-0227
通讯作者	北京8701信箱
英文摘要	Driven by a waveform inflow, multiple X line reconnection is initiated in a long current layer, and the plasmoids are bound between two neighboring reconnection sites. We investigate the behaviors of the plasmoid-like structures in the absence and presence of an initial guide field B-y0 normalized by B-0 (B-0 is the initial intensity of B-x field at the top and bottom boundaries of the simulation domain) using a Hall magnetohydrodynamic (MHD) code. For the case with B-y0 = 0 the profiles of the out-of-plane B-y component are the bipolar signature or the bipolar wavelike signature which is caused by Hall effect and independent of the external mechanism. Such B-y features are in line with the observed signature of a closed-loop-like plasmoid in the magnetotail. The bipolar and fluctuation signatures of B-y have an asymmetric feature in the presence of a small B-y0(= 0.1), and the B-y profile becomes a positive signature as B-y0 reaches or exceeds 0.3. In the case of B-y0 = 0.5, a B-y bulge appears in the B-y signature when the enhanced B-y regions caused by Hall effect take place in the plasmoid. The B-y bulge evolves into a peaking signature, whose maximum (B-y vertical bar(max)) is quickly raised and approaches the lobe magnetic field strength. Such a significant enhancement of the B-y component in the central region of the plasmoid might be representative of the observed strong core field in the magnetic flux rope. The present results indicate the following implications: (1) Hall effect and a preexisting cross-tail component B-y are two important factors controlling the occurrence of various plasmoid-like structures in the magnetotail. (2) In the later phase the nonlinear interaction between Hall effect and the B-y flux added by the plasma inflow makes a most important contribution to the growth of the core B-y field.
学科主题	空间物理
收录类别	SCI
原文出处	http://www.agu.org/pubs/crossref/2009/2009JA014257.shtml
语种	英语
内容类型	期刊论文
源URL	[http://ir.cssar.ac.cn/handle/122/1136]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	Liu, C. X.,Jin, S. P.,魏奉思.,et al. Plasmoid-like structures in multiple X line Hall MHD reconnection[J]. Journal of Geophysical Research-Space Physics,2009,114:A10208.
APA	Liu, C. X.,Jin, S. P.,魏奉思.,Lu, Q. M.,&Yang, H. A..(2009).Plasmoid-like structures in multiple X line Hall MHD reconnection.Journal of Geophysical Research-Space Physics,114,A10208.
MLA	Liu, C. X.,et al."Plasmoid-like structures in multiple X line Hall MHD reconnection".Journal of Geophysical Research-Space Physics 114(2009):A10208.