论文标题
从不连贯的场到连贯的重新连接：了解对流驱动的冠状冠在安静的阳光下加热
From incoherent field to coherent reconnection: understanding convection-driven coronal heating in the quiet Sun
论文作者
论文摘要
安静的太阳中的磁重新连接是一种始终观察到的现象，最近可以通过现实分层和对流驱动的重新连接的3D数值模型模拟它变得可行。我们旨在说明安静的太阳场可以通过对流运动驱动的磁重新连接有助于太阳大气加热的方式。我们还旨在将分层模型与早期理想化的冠状模型进行比较，以重新连接驱动因素和拓扑条件。我们分析了对宁静的太阳的模拟，其中复杂的冠状磁场是由基础对流驱动的。我们采用了一系列拉格朗日标记来追踪与磁重新连接和大气加热相关的特定磁特征的时空行为。大规模重新连接驱动的加热事件发生在模拟的电晕中，以扁平的X形特征为特征，其特征是弱场和高电流。相关的特征包括平滑的水平场，街机和水平通量绳，最终与上覆的场重新连接，使冠状血浆温度提高到1.47 mk。我们发现我们的结果与理想化的冠状耀斑模型非常吻合，这表明相同的物理概念是有效的。我们还发现，重新连接的通量绳和街机既不是由任何明显的连贯的磁通出现形成，也不是由任何有序的光电运动或磁通取消形成的。取而代之的是，它们似乎仅仅是由于先前存在的纠结野外线的自以为是的对流而发展的。这种逐渐的排序表明，位于光磁通浓度或以上的较小的重新连接事件中，磁性螺旋性反向级联。我们建议，此案代表了在真正的安静阳光下可能无处不在的加热事件。
Magnetic reconnection in the quiet Sun is a phenomenon that is consistently observed, and it has recently become feasible to simulate via 3D numerical models of realistically stratified and convection-driven reconnection. We aim to illustrate ways by which quiet Sun fields may contribute to solar atmospheric heating via magnetic reconnection that is driven by convective motion. We also aim to compare our stratified model to earlier idealized coronal models in terms of reconnection drivers and topological conditions. We analyzed a simulation of the quiet Sun in which a complex coronal magnetic field is self-consistently driven by the underlying convection. We employed a selection of Lagrangian markers to trace the spatiotemporal behavior of specific magnetic features that are relevant to magnetic reconnection and atmospheric heating. A large-scale reconnection-driven heating event occurs in the simulated corona, in a flattened X-shaped feature characterized by a weak field and high current. Relevant features include a smooth overlying horizontal field, an arcade, and a horizontal flux rope which eventually reconnect with the overlying field, raising coronal plasma temperatures up to 1.47 MK. We find that our results are in good agreement with idealized coronal flare models, which demonstrates that the same physical concepts are valid. We also find that the reconnecting flux rope and arcade are neither formed by any obvious coherent flux emergence, nor by any ordered photospheric motion or flux cancellation. Instead, they seem to develop merely from the self-consistent convective driving of pre-existing tangled field lines. This gradual ordering suggests an inverse cascade of magnetic helicity via smaller reconnection events, located at or above photospheric flux concentrations. We suggest that this case is representative of heating events that may be ubiquitous in the real quiet Sun.
