论文标题
在磁流失动力湍流中重新连接驱动的能量级联
Reconnection-Driven Energy Cascade in Magnetohydrodynamic Turbulence
论文作者
论文摘要
在许多天体物理系统（包括太阳大气层）中，磁流失动力学湍流调节能量从大尺度转移到小尺度。我们执行三维磁流体动力模拟，并具有前所未有的大磁性雷诺数，以揭示磁场线的快速重新连接如何改变湍流能量级联的经典范式。通过将细长的电流板分解成小磁通绳（或浆液型）的链，磁重新连接导致了一系列新的湍流能量级联，其中能量传递的速率受浆液的生长速率控制。结果，湍流的能量光谱陡峭并获得-2.2的光谱指数，伴随着湍流涡流各向异性的变化。可以通过当前和未来的航天器和望远镜进一步探索浆液的无处存冰及其对太阳冠状加热的后果。
Magnetohydrodynamic turbulence regulates the transfer of energy from large to small scales in many astrophysical systems, including the solar atmosphere. We perform three-dimensional magnetohydrodynamic simulations with unprecedentedly large magnetic Reynolds number to reveal how rapid reconnection of magnetic field lines changes the classical paradigm of the turbulent energy cascade. By breaking elongated current sheets into chains of small magnetic flux ropes (or plasmoids), magnetic reconnection leads to a new range of turbulent energy cascade, where the rate of energy transfer is controlled by the growth rate of the plasmoids. As a consequence, the turbulent energy spectra steepen and attain a spectral index of -2.2 that is accompanied by changes in the anisotropy of turbulence eddies. The omnipresence of plasmoids and their consequences on, e.g., solar coronal heating, can be further explored with current and future spacecraft and telescopes.
