The influence of out‐of‐plane shear flow on Hall magnetic reconnection and FTE generation
The influence of out‐of‐plane shear flow on Hall magnetic reconnection and FTE generation
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DOI：
10.1002/jgra.50417
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发表时间：
2013-07
期刊：
影响因子：
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通讯作者：
Yang Chen;C. Xiao;Xiaogang Wang;Jiaqi Wang;Hui Zhang;Z. Pu;Zhiwei Ma;Zhibin Guo
中科院分区：
文献类型：
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作者：
Yang Chen;C. Xiao;Xiaogang Wang;Jiaqi Wang;Hui Zhang;Z. Pu;Zhiwei Ma;Zhibin Guo
基于三维霍尔磁流体动力学（MHD）代码进行面外剪切流驱动的磁重联。模拟结果表明，面外剪切流可以驱动二次撕裂失稳，快速形成无导向场的磁岛或有导向场的磁绳。研究发现，~240阿尔文时间内磁力绳的尺寸达到约20a（a是初始电流片厚度），大约为一个地球半径，这是在白天磁层顶观测到的磁通传递事件（FTE）的典型规模。从基于THEMIS数据的特殊模拟案例发现，霍尔MHD模拟很好地再现了观测到的FTE，这可能为FTE的产生机制提供一些线索。
Magnetic reconnection driven by an out‐of‐plane shear flow is carried out based on the three‐dimensional Hall magnetohydrodynamics (MHD) code. The simulation results indicate that an out‐of‐plane shear flow can drive a secondary tearing instability to quickly form a magnetic island without a guide field or a flux rope with a guide field. It is found that the size of the flux rope within ~240 Alfven time reaches about 20a (a is the initial current sheet thickness) that is roughly one Earth radius, the typical scale of Flux Transfer Event (FTE) observed at the dayside magnetopause. From a special simulation case based on the THEMIS data, it is found that an observed FTE is well reproduced by the Hall MHD simulation, which may give some clues on the generation mechanism of FTE.