The ocean boundary layer (OBL) is forced by atmosphere-ocean and sea ice-ocean momentum fluxes, wave dynamics, and buoyancy; in coastal zones, OBL dynamics are further complicated by additional shear from the seafloor. Among numerous other phenomena, coastal mixing affects dispersion of anthropogenic quantities, erosion and turbidity, and benthic sequestration. In the OBL, interaction of wind-induced shear and surface waves manifests so-called Langmuir turbulence and distinctive Langmuir cells under favorable conditions, which have implications for the aforementioned coastal processes. Large-eddy simulation was used to dynamically sample the flow during relative extremes in bathymetric stress and vertical velocity. Probability density functions of vertical velocity are bimodal, the signature of persistent upwelling and downwelling within Langmuir cells, and this attribute manifests itself in the bathymetric stress, revealing a phase-locked modulation. We report modulation between negative vertical velocity (downwelling) and relatively elevated bathymetric stresses, thereby revealing that coastal Langmuir turbulence has direct implications for erosion and turbidity.

中文翻译：

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沿海朗缪尔环流引起测深应力的锁相调制

海洋边界层（OBL）受大气-海洋和海冰-海洋动量通量，波浪动力学和浮力的驱使；在沿海地区，由于海底的额外剪切，OBL动力学进一步复杂化。在众多其他现象中，沿海混合影响人为数量的分散，侵蚀和浑浊以及底栖固存。在OBL中，在有利条件下，风切变和面波的相互作用表现出所谓的朗缪尔湍流和独特的朗缪尔细胞，这对上述沿海过程具有影响。大涡模拟用于在测深应力和垂直速度的相对极端情况下动态采样流量。垂直速度的概率密度函数是双峰的，这是Langmuir细胞内持续上升和下降的信号，这一特性在测深应力中表现出来，揭示了锁相调制。我们报告负垂直速度（下降）和相对升高的测深应力之间的调制，从而揭示了沿海Langmuir湍流对侵蚀和浊度有直接影响。