Statistical and spectral properties of magnetic islands in reconnecting current sheets during two-ribbon flares
Statistical and spectral properties of magnetic islands in reconnecting current sheets during two-ribbon flares
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双带耀斑期间重新连接电流片时磁岛的统计和光谱特性
DOI：
10.1063/1.4816711
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发表时间：
2013-07
影响因子：
2.2
通讯作者：
Raymond, John C.
中科院分区：
文献类型：
--
作者：
Shen, Chengcai;Lin, Jun;Murphy, Nicholas A.;Raymond, John C.
我们进行了一组二维电阻性磁流体动力学模拟，以研究太阳喷发期间形成的电流片中发生的重联过程。重新连接逐渐开始，并在当前片内产生小规模的结构，其一端锚定到底部边界，另一端开放。我们研究的主要特征包括在片中流动的等离子体团（或等离子体斑点），以及相邻岛屿对之间的X点。精细结构的统计特性和光谱能量对这些属性的依赖关系进行检查。等离子体团的通量和尺寸分布函数在大尺度下大致遵循平方幂反比定律。质量分布函数在大尺度上是陡峭的，在小尺度上是浅的。大小分布也表明，等离子体团在形成后不久是高度不对称的，而较老的等离子体团往往更圆。电流片内部的磁能和动能的光谱分布都符合幂律。相应的谱指数c随系统的磁雷诺数R-m而变化，但当R-m较大（> 10（5））时趋于常数。斑点的运动和生长改变了光谱指数。新岛屿的生长导致功率谱变陡，但当旧的和大的等离子体团离开计算域时，功率谱变浅。(C)2013 AIP出版有限责任公司。
We perform a set of two dimensional resistive magnetohydrodynamic simulations to study the reconnection process occurring in current sheets that develop during solar eruptions. Reconnection commences gradually and produces small-scale structures inside the current sheet, which has one end anchored to the bottom boundary and the other end open. The main features we study include plasmoids (or plasma blobs) flowing in the sheet, and X-points between pairs of adjacent islands. The statistical properties of the fine structure and the dependence of the spectral energy on these properties are examined. The flux and size distribution functions of plasmoids roughly follow inverse square power laws at large scales. The mass distribution function is steep at large scales and shallow at small scales. The size distribution also shows that plasmoids are highly asymmetric soon after being formed, while older plasmoids tend to be more circular. The spectral profiles of magnetic and kinetic energy inside the current sheet are both consistent with a power law. The corresponding spectral indices c are found to vary with the magnetic Reynolds number R-m of the system, but tend to approach a constant for large R-m (> 10(5)). The motion and growth of blobs change the spectral index. The growth of new islands causes the power spectrum to steepen, but it becomes shallower when old and large plasmoids leave the computational domain. (C) 2013 AIP Publishing LLC.
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DOI：
10.1088/0004-637x/737/1/14
发表时间：
2011-08
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Chengcai Shen;Jun Lin;N. Murphy
通讯作者：
Chengcai Shen;Jun Lin;N. Murphy
DOI：
10.1088/0004-637x/735/2/102
发表时间：
2011-03
期刊：
The Astrophysical Journal
影响因子：
--
作者：
G. Kowal;E. M. de Gouveia Dal Pino;A. Lazarian
通讯作者：
G. Kowal;E. M. de Gouveia Dal Pino;A. Lazarian
影响因子：
6.5
作者：
M. Bárta;B. Vršnak;M. Karlický
通讯作者：
M. Bárta;B. Vršnak;M. Karlický
影响因子：
8.6
作者：
D. Uzdensky;N. Loureiro;A. Schekochihin
通讯作者：
D. Uzdensky;N. Loureiro;A. Schekochihin
影响因子：
4.1
作者：
S. Zalesak
通讯作者：
S. Zalesak