Angular momentum transport, layering, and zonal jet formation by the GSF instability: non-linear simulations at a general latitude
Angular momentum transport, layering, and zonal jet formation by the GSF instability: non-linear simulations at a general latitude
复制标题
GSF 不稳定性引起的角动量传输、分层和纬向射流形成：一般纬度的非线性模拟
DOI：
10.1093/mnras/staa1327
复制
发表时间：
2020
影响因子：
4.8
通讯作者：
Steven M. Tobias
中科院分区：
文献类型：
--
作者：
A. Barker;Chris A. Jones;Steven M. Tobias
我们继续我们的调查的非线性演化的Goldreich-Schubert-Schuberke（GSF）的不稳定性在差分旋转辐射区。这种不稳定性可能是在恒星和巨行星中传输角动量的关键因素，但其非线性演化仍然没有被探索。在以前的论文中，我们考虑了赤道不稳定性，而在这里，我们模拟的不稳定性在一般纬度的第一次。我们采用了本地笛卡尔Boussinesq模型在修改后的剪切盒我们的模拟，但我们也进行了一些模拟与无应力，不可穿透，径向边界。在研究其非线性演化之前，我们首先回顾了线性不稳定性并得到了一些新的结果。的不稳定性被认为是非常不同的行为相比，它的行为在赤道。特别是，在这里，我们观察到强纬向喷流的发展（“分层”的角动量），这可以大大提高角动量传输，特别是在轴对称模拟。一般来说，射流相对于局部重力倾斜一个角度，该角度最初与线性模式的角度相对应，但该角度随着时间的推移而变化，并取决于流动的强度。的不稳定性传输角动量更有效地（由几个数量级）比它在赤道，我们估计，GSF不稳定性可能有助于失踪的角动量运输所需的红巨星和亚巨星。它也可能在太阳速跃层的长期演化和热彗星的大气动力学中发挥作用。
We continue our investigation into the non-linear evolution of the Goldreich–Schubert–Fricke (GSF) instability in differentially rotating radiation zones. This instability may be a key player in transporting angular momentum in stars and giant planets, but its non-linear evolution remains mostly unexplored. In a previous paper we considered the equatorial instability, whereas here we simulate the instability at a general latitude for the first time. We adopt a local Cartesian Boussinesq model in a modified shearing box for most of our simulations, but we also perform some simulations with stress-free, impenetrable, radial boundaries. We first revisit the linear instability and derive some new results, before studying its non-linear evolution. The instability is found to behave very differently compared with its behaviour at the equator. In particular, here we observe the development of strong zonal jets (‘layering’ in the angular momentum), which can considerably enhance angular momentum transport, particularly in axisymmetric simulations. The jets are, in general, tilted with respect to the local gravity by an angle that corresponds initially with that of the linear modes, but which evolves with time and depends on the strength of the flow. The instability transports angular momentum much more efficiently (by several orders of magnitude) than it does at the equator, and we estimate that the GSF instability could contribute to the missing angular momentum transport required in both red giant and subgiant stars. It could also play a role in the long-term evolution of the solar tachocline and the atmospheric dynamics of hot Jupiters.
DOI：
10.1146/annurev-astro-091918-104359
发表时间：
2018-09
影响因子：
33.3
作者：
C. Aerts;S. Mathis;T. Rogers
通讯作者：
C. Aerts;S. Mathis;T. Rogers
吸积盘垂直剪切不稳定性的线性和非线性演化
影响因子：
4.8
作者：
Nelson R
通讯作者：
Nelson R
GSF 不稳定性引起的角动量传递：赤道处的非线性模拟
影响因子：
4.8
作者：
Barker A
通讯作者：
Barker A