Influences of sub-Alfvenic shear flows on nonlinear evolution of magnetic reconnection in compressible plasmas
Influences of sub-Alfvenic shear flows on nonlinear evolution of magnetic reconnection in compressible plasmas
复制标题
亚芬尼剪切流对可压缩等离子体磁重联非线性演化的影响
DOI：
10.1063/1.3643792
复制
发表时间：
2011-09-01
影响因子：
2.2
通讯作者：
Ma, Z. W.
中科院分区：
文献类型：
--
作者：
Zhang, X.;Li, L. J.;Ma, Z. W.
在可压缩电阻MHD和可压缩霍尔MHD的框架下研究了亚芬尼剪切流对磁重联非线性演化的影响。首次发现亚芬尼剪切流可以稳定或破坏磁重联，其主要由等离子体β和剪切流半厚度(lambda(nu))决定。当β等离子体β小于或接近1时，剪切流对磁重联表现出抑制作用，而增强作用几乎消失，这与上下流入区存在一对不连续点有关。在高β等离子体中，当剪切流的半厚度超过临界值时，剪切流对磁重联具有增强作用，这与不可压缩模拟的结果吻合较好。考虑到霍尔效应，剪切流仍然可以稳定或不稳定磁重联，但随着离子惯性长度 d(i) 的增加，增强效应会变弱。 (C) 2011 年美国物理研究所。 [doi:10.1063/1.3643792]
Influences of sub-Alfvenic shear flows on the nonlinear evolution of the magnetic reconnection are studied in the framework of compressible resistive MHD and compressible Hall MHD. It is found for the first time that the sub-Alfvenic shear flow can either stabilize or destabilize magnetic reconnection, which is mainly determined by the plasma beta and the half thickness of the shear flow (lambda(nu)). The shear flow exhibits a suppressing effect on magnetic reconnection and the boosting effect nearly disappears for the beta plasma beta less than or similar to 1, which is associated with the presence of a pair of discontinuities in the upper and lower inflow region. The shear flow has the boosting effect on magnetic reconnection when the half thickness of the shear flow exceeds a critical value in the high beta plasma which is in a good agreement with the results from incompressible simulation. With the inclusion of the Hall effect, shear flow can still either stabilize or destabilize magnetic reconnection, but the boosting effect becomes weaker as the ion inertial length d(i) increases. (C) 2011 American Institute of Physics. [doi:10.1063/1.3643792]