Is magnetic topology important for heating the solar atmosphere?
Is magnetic topology important for heating the solar atmosphere?
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DOI：
10.1098/rsta.2014.0264
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
C. Parnell;J. E. H. Stevenson;J. Threlfall;S. J. Edwards
中科院分区：
文献类型：
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作者：
C. Parnell;J. E. H. Stevenson;J. Threlfall;S. J. Edwards
磁场渗透整个太阳大气层，在局部和全球尺度上编织出极其复杂的图案。为了理解这个磁场纠缠网的本质，可以确定它的磁骨架，它形成了拓扑上不同的通量域之间的边界。磁骨架由零点、分离矩阵表面、棘和分离器组成。骨架通常用于清晰地可视化磁性配置的关键元素，但骨架的某些部分也是电流和波可能聚集和消散的位置。在这篇综述中，磁骨架的性质在全球和局部尺度上，在太阳周期的时间尺度上，解释。讨论了波脉冲在零点和分离点附近的行为，以及电流层的形成和在同一特征处的重连。这些过程中的每一个都会导致太阳大气的加热，但是总的来说，它们是否提供了足够的热量，分布在足够广泛的区域，来解释整个太阳大气中的能量损失？在这里，我们考虑三个不同的太阳区域：活跃区域，开放区域和安静的太阳。我们发现活跃区域和开放区域的加热极不可能是由于拓扑特征的重连接或波耗散，但这些可能在安静太阳的加热中起作用。在活动区域，没有复杂的拓扑结构可能在允许大量能量积聚并随后以太阳耀斑的形式爆炸释放方面发挥重要作用。此外，了解开放磁场区域的复杂边界（磁骨架提供的）对于确定太阳风的主要加速机制可能非常重要。
Magnetic fields permeate the entire solar atmosphere weaving an extremely complex pattern on both local and global scales. In order to understand the nature of this tangled web of magnetic fields, its magnetic skeleton, which forms the boundaries between topologically distinct flux domains, may be determined. The magnetic skeleton consists of null points, separatrix surfaces, spines and separators. The skeleton is often used to clearly visualize key elements of the magnetic configuration, but parts of the skeleton are also locations where currents and waves may collect and dissipate. In this review, the nature of the magnetic skeleton on both global and local scales, over solar cycle time scales, is explained. The behaviour of wave pulses in the vicinity of both nulls and separators is discussed and so too is the formation of current layers and reconnection at the same features. Each of these processes leads to heating of the solar atmosphere, but collectively do they provide enough heat, spread over a wide enough area, to explain the energy losses throughout the solar atmosphere? Here, we consider this question for the three different solar regions: active regions, open-field regions and the quiet Sun. We find that the heating of active regions and open-field regions is highly unlikely to be due to reconnection or wave dissipation at topological features, but it is possible that these may play a role in the heating of the quiet Sun. In active regions, the absence of a complex topology may play an important role in allowing large energies to build up and then, subsequently, be explosively released in the form of a solar flare. Additionally, knowledge of the intricate boundaries of open-field regions (which the magnetic skeleton provides) could be very important in determining the main acceleration mechanism(s) of the solar wind.