Roles of initial current carrier in the distribution of field-aligned current in 3-D Hall MHD simulations
Roles of initial current carrier in the distribution of field-aligned current in 3-D Hall MHD simulations
复制标题
3 维霍尔 MHD 模拟中初始载流子在场对准电流分布中的作用
DOI：
10.1007/s11431-008-0020-1
复制
发表时间：
2008-03
期刊：
影响因子：
--
通讯作者：
Ma ZhiWei
中科院分区：
文献类型：
--
作者：
Zhou XuZhi;Zhang XianGuo;Pu ZuYin;Ma ZhiWei
通过三维Hall MHD仿真研究了初始电流载流子在磁场拓扑结构中的作用、场向电流（FACs）的产生和分布以及alfvsamn波的出现。考虑到离子对初始电流的贡献，得到的磁场拓扑结构变得更加复杂。在某些情况下，仿真箱中不仅出现了传统的双四极杆结构，还出现了反四极杆结构。这可以解释扩散区附近的观测特征，这与霍尔MHD理论与电子携带的总初始电流不一致。还出现了其他几个有趣的特性。首先，电子和离子的运动在小的等离子体区域（霍尔效应区域）中相互解耦，其尺度小于或与离子惯性长度或离子皮肤深度（di=c/ωp）相当。在非霍尔效应区，在初始定向运动的离子影响下，整体磁性结构向+y方向移动。而在霍尔效应区，磁力线在−y方向弯曲，主要由电子运动控制，然后产生byis。其次，FACs的出现是by的结果。与之前的Hall MHD模拟结果相比，生成的FACs在+y方向上移位，从而打破了黎明-黄昏对称性。第三，我们模拟的walsamn关系与霍尔等离子体中的walsamn关系是一致的，从而证实了alfvsamn波的存在。
A three-dimensional (3-D) Hall MHD simulation is carried out to study the roles of initial current carrier in the topology of magnetic field, the generation and distribution of field aligned currents (FACs), and the appearance of Alfvén waves. Considering the contribution of ions to the initial current, the topology of the obtained magnetic field turns to be more complex. In some cases, it is found that not only the traditionalByquadrupole structure but also a reversalByquadrupole structure appears in the simulation box. This can explain the observational features near the diffusion region, which are inconsistent with the Hall MHD theory with the total initial current carried by electrons. Several other interesting features are also emerged. First, motions of electrons and ions are decoupled from each other in the small plasma region (Hall effect region) with a scale less than or comparable with the ion inertial length or ion skin depthdi=c/ωp. In the non-Hall effect region, the global magnetic structure is shifted in +ydirection under the influence of ions with initialydirectional motion. However, in the Hall effect region, magnetic field lines are bent in −ydirection, mainly controlled by the motion of electrons, thenByis generated. Second, FACs emerge as a result of the appearance ofBy. Compared with the prior Hall MHD simulation results, the generated FACs shift in +ydirection, and hence the dawn-dusk symmetry is broken. Third, the Walén relation in our simulations is consistent with the Walén relation in Hall plasma, thus the presence of Alfvén wave is confirmed.
登录
查看更多内容
影响因子：
--
作者：
Tetsuya Sato;R. Walker;M. Ashour‐Abdalla
通讯作者：
Tetsuya Sato;R. Walker;M. Ashour‐Abdalla
影响因子：
--
作者：
M. Ugai
通讯作者：
M. Ugai
影响因子：
5.2
作者：
Y. Yamade;M. Fujimoto;N. Yokokawa;M. Nakamura
通讯作者：
Y. Yamade;M. Fujimoto;N. Yokokawa;M. Nakamura
影响因子：
10.3
作者：
C. Russell;R. Elphic
通讯作者：
C. Russell;R. Elphic
影响因子：
--
作者：
B. Sonnerup;G. Paschmann;I. Papamastorakis;N. Sckopke;G. Haerendel;S. Bame;J. Asbridge;J. Gosling;C. Russell
通讯作者：
B. Sonnerup;G. Paschmann;I. Papamastorakis;N. Sckopke;G. Haerendel;S. Bame;J. Asbridge;J. Gosling;C. Russell