This study investigates the influence of suspended kelp farms on ocean mixed layer hydrodynamics in the presence of currents and waves. We use the large eddy simulation method, where the wave effect is incorporated by solving the wave-averaged equations. Distinct Langmuir circulation patterns are generated within various suspended farm configurations, including horizontally uniform kelp blocks and spaced kelp rows. Intensified turbulence arises from the farm-generated Langmuir circulation, as opposed to the standard Langmuir turbulence observed without a farm. The creation of Langmuir circulation within the farm is attributed to two primary factors depending on farm configuration: (i) enhanced vertical shear due to kelp frond area density variability, and (ii) enhanced lateral shear due to canopy discontinuity at lateral edges of spaced rows. Both enhanced vertical and lateral shear of streamwise velocity, representing the lateral and vertical vorticity components, respectively, can be tilted into downstream vorticity to create Langmuir circulation. This vorticity tilting is driven by the Craik–Leibovich vortex force associated with the Stokes drift of surface gravity waves. In addition to the farm-generated Langmuir turbulence, canopy shear layer turbulence is created at the farm bottom edge due to drag discontinuity. The intensity of different types of turbulence depends on both kelp frond area density and the geometric configuration of the farm. The farm-generated turbulence has substantial consequences for nutrient supply and kelp growth. These findings also underscore the significance of the presence of obstacle structures in modifying ocean mixed layer characteristics.

中文翻译：

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悬浮海带养殖场中的朗缪尔湍流

本研究研究了在海流和波浪存在的情况下，悬浮海带养殖场对海洋混合层流体动力学的影响。我们使用大涡模拟方法，通过求解波浪平均方程来纳入波浪效应。不同的悬浮农场配置会产生不同的朗缪尔循环模式，包括水平均匀的海带块和间隔的海带行。强化的湍流源自农场产生的朗缪尔环流，这与在没有农场的情况下观察到的标准朗缪尔湍流相反。农场内朗缪尔循环的产生归因于两个主要因素，具体取决于农场配置：(i) 由于海带叶面积密度变化而增强的垂直剪切力，以及 (ii) 由于间隔行的侧边缘处的树冠不连续性而增强的横向剪切力。流向速度的增强的垂直和侧向剪切分别代表侧向和垂直涡度分量，可以倾斜到下游涡度以产生朗缪尔环流。这种涡度倾斜是由与表面重力波的斯托克斯漂移相关的克雷克-莱博维奇涡力驱动的。除了农场产生的朗缪尔湍流之外，由于阻力不连续性，在农场底部边缘还会产生冠层剪切层湍流。不同类型湍流的强度取决于海带叶面积密度和农场的几何配置。农场产生的湍流对养分供应和海带生长产生重大影响。这些发现还强调了障碍物结构的存在在改变海洋混合层特征方面的重要性。