Double-diffusive Magnetic Layering
Double-diffusive Magnetic Layering
复制标题
双扩散磁层
DOI：
--
复制
发表时间：
2021
影响因子：
4.9
通讯作者：
N. Brummell
中科院分区：
文献类型：
--
作者：
D. Hughes;N. Brummell
双扩散系统，如热溶质对流，其中的密度取决于两个组件，以不同的速度扩散，是容易稳定和振荡不稳定。这样的系统可以演变成分层状态，其中两个组件，也是密度，采用“楼梯”的轮廓。湍流输运在分层状态下显著增强。在这里，我们利用磁浮力和热溶质对流之间的类比，以证明磁性分层的现象。我们研究了长期的非线性演化的垂直分层的水平磁场在所谓的“扩散制度”，振荡的线性不稳定性操作。出于天体物理学的考虑，我们考虑了粘性和磁扩散率远小于热扩散率的情况。我们表明，扩散分层甚至可以发生亚绝热温度梯度。磁分层可能与恒星辐射区有关，并对热量、磁场和化学元素的湍流传输产生影响。
Double-diffusive systems, such as thermosolutal convection, in which the density depends on two components that diffuse at different rates, are prone to both steady and oscillatory instabilities. Such systems can evolve into layered states, in which both components, and also the density, adopt a “staircase” profile. Turbulent transport is enhanced significantly in the layered state. Here we exploit an analogy between magnetic buoyancy and thermosolutal convection in order to demonstrate the phenomenon of magnetic layering. We examine the long-term nonlinear evolution of a vertically stratified horizontal magnetic field in the so-called “diffusive regime,” where an oscillatory linear instability operates. Motivated astrophysically, we consider the case where the viscous and magnetic diffusivities are much smaller than the thermal diffusivity. We demonstrate that diffusive layering can occur even for subadiabatic temperature gradients. Magnetic layering may be relevant for stellar radiative zones, with implications for the turbulent transport of heat, magnetic field, and chemical elements.
影响因子：
1.3
作者：
Bowker J
通讯作者：
Bowker J