Solar differential rotation: hints to reproduce a near-surface shear layer in global simulations
Solar differential rotation: hints to reproduce a near-surface shear layer in global simulations
复制标题
太阳差分自转：在全球模拟中重现近地表剪切层的提示
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
N. Mansour
中科院分区：
文献类型：
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作者：
G. Guerrero;P. Smolarkiewicz;A. Kosovichev;N. Mansour
太阳内部的对流湍流运动以及由此产生的平均流动决定了太阳磁场的演化。为了更好地理解这些流动，我们研究了层结类似于太阳内部的球壳中的滞弹性旋转对流。这项研究是通过使用EULAG程序进行的数值模拟来完成的。由于数值形式的原因，这些模拟被称为隐式大涡模拟(ILE)，因为它们本质上捕捉到了未分辨的小尺度的贡献，同时最大化了有效雷诺数。我们复制了以前的一些结果，发现了浮力和自转主导型之间的转变，这导致了反太阳或类似太阳的自转模式。即使旋转剖面以Taylor-Proudman柱状旋转为主，我们也能够再现塔可跃层和低纬近地表剪切层。我们发现，由于不同的子网格尺度贡献，模拟结果依赖于网格分辨率。
Abstract Convective turbulent motions in the solar interior, as well as the mean flows resulting from them, determine the evolution of the solar magnetic field. With the aim to get a better understanding of these flows we study anelastic rotating convection in a spherical shell whose stratification resembles that of the solar interior. This study is done through numerical simulations performed with the EULAG code. Due to the numerical formulation, these simulations are known as implicit large eddy simulations (ILES), since they intrinsically capture the contribution of, non-resolved, small scales at the same time maximizing the effective Reynolds number. We reproduce some previous results and find a transition between buoyancy and rotation dominated regimes which results in anti-solar or solar like rotation patterns. Even thought the rotation profiles are dominated by Taylor-Proudman columnar rotation, we are able to reproduce the tachocline and a low latitude near-surface shear layer. We find that simulations results depend on the grid resolution as a consequence of a different sub-grid scale contribution.