Linear stability analysis of Richter rolls
Linear stability analysis of Richter rolls
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里氏辊线性稳定性分析
DOI：
10.1029/2003gl018337
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发表时间：
2003
影响因子：
5.2
通讯作者：
T. Jordan
中科院分区：
文献类型：
--
作者：
J. Korenaga;T. Jordan
通过在存在垂直剪切的情况下纵向卷轴的 3D 线性稳定性分析来研究岩石圈下对流的平面形状。考虑最多 106 的瑞利数。纵向滚动不稳定的转变瑞利数是作为表面速度的函数导出的。除非非线性变得极端，否则非线性垂直剪切的影响是微不足道的。我们的结果与之前的研究非常一致，除了在高瑞利数时，由于固有的时间依赖性对流，滚动稳定性的含义变得模糊。当应用于上地幔小规模对流时，我们的结果表明，如果上地幔粘度相对较高（~1020 Pa·s），滚动稳定性对板块速度非常敏感；里氏滚动可能只出现在快速移动的板块（例如太平洋板块）下方。
The planform of sublithospheric convection is studied by a 3‐D linear stability analysis of longitudinal rolls in the presence of vertical shear. Rayleigh numbers up to 106 are considered. The transition Rayleigh number over which longitudinal rolls are unstable is derived as a function of surface velocity. Effects of nonlinear vertical shear are shown to be insignificant unless nonlinearity becomes extreme. Our results are in good agreement with previous studies, except at high Rayleigh numbers where the meaning of roll stability becomes ambiguous owning to inherently time‐dependent convection. When applied to small‐scale convection in the upper mantle, our results suggest that the roll stability is very sensitive to plate velocity if the upper mantle viscosity is relatively high (∼1020 Pa s); Richter rolls may be expected only beneath fast‐moving plates such as the Pacific plate.