Measurements of Enhanced Near-Surface Turbulence under Windrows
Measurements of Enhanced Near-Surface Turbulence under Windrows
复制标题
料堆下增强的近地表湍流的测量
DOI：
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发表时间：
2020
影响因子：
3.5
通讯作者：
D. Dumont
中科院分区：
文献类型：
--
作者：
S. Zippel;T. Maksym;M. E. Scully;P. Sutherland;D. Dumont
2018年冬天，在魁北克省里穆斯基外的一个浅海湾中对波浪、风、湍流以及风堆的几何形状和环流进行了观测。安装在一个小的黄道带上的前视脉冲相干ADCP测量的水速度显示展向（交叉料堆）收敛，流向（顺风）速度增强，并在料堆下降流，一致的看法，料堆是反向旋转的风对齐的涡对的结果。用声学后向散射和表面成像测量的料堆间距约为水深的两倍，这表明纵横比为1。从ADCP测得的湍流的大小和垂直分布是一致的，与以前的缩放和观察近地表湍流下破碎波，耗散率更大，衰减速度更快，垂直比预期从剪切驱动的边界层。耗散率的测量被划分到内，和外的料堆收敛区，和收敛区内的测量被发现是近一个数量级大于具有类似的垂直结构的外部。时间尺度的比率表明，湍流可能消散之前，它可以水平平流到收敛，但平流的波能收敛可能会提高表面通量的TKE，可以解释升高湍流的料堆。这些结果增加了有限数量的相互矛盾的观察湍流变化，由于料堆，这可能会修改气体通量，热量和动量输送的表面边界层。
Observations of waves, winds, turbulence, and the geometry and circulation of windrows were made in a shallow bay in the winter of 2018 outside of Rimouski, Québec. Water velocities measured from a forward-looking pulse-coherent ADCP mounted on a small zodiac show spanwise (cross-windrow) convergence, streamwise (downwind) velocity enhancement, and downwelling in the windrows, consistent with the view that windrows are the result of counterrotating pairs of wind-aligned vortices. The spacing of windrows, measured with acoustic backscatter and with surface imagery, was measured to be approximately twice the water depth, which suggests an aspect ratio of 1. The magnitude and vertical distribution of turbulence measured from the ADCP are consistent with a previous scaling and observations of near-surface turbulence under breaking waves, with dissipation rates larger and decaying faster vertically than what is expected from a shear-driven boundary layer. Measurements of dissipation rate are partitioned to within, and outside of the windrow convergence zones, and measurements inside the convergence zones are found to be nearly an order of magnitude larger than those outside with similar vertical structure. A ratio of time scales suggests that turbulence likely dissipates before it can be advected horizontally into convergences, but the advection of wave energy into convergences may elevate the surface flux of TKE and could explain the elevated turbulence in the windrows. These results add to a limited number of conflicting observations of turbulence variability due to windrows, which may modify gas flux, and heat and momentum transport in the surface boundary layer.
斯托克斯漂移衰变尺度对朗缪尔湍流的影响
影响因子：
3.5
作者：
Kukulka, Tobias;Harcourt, Ramsey R.
通讯作者：
Harcourt, Ramsey R.