Lagrangian transport by breaking surface waves
Lagrangian transport by breaking surface waves
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DOI：
10.1017/jfm.2017.548
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发表时间：
2017-10-25
影响因子：
3.7
通讯作者：
Melville, W. Kendall
中科院分区：
文献类型：
--
作者：
Deike, Luc;Pizzo, Nick;Melville, W. Kendall
研究了非破碎聚焦波包和破碎聚焦波包的拉格朗日输运。我们提出了直接数值模拟的两相空气-水的Navier-Stokes方程描述聚焦波包，调查拉格朗日漂移跟踪示踪粒子在水中之前，期间和之后的破碎事件。非破坏聚焦包的净水平传输很好地描述了经典的斯托克斯漂移，无论是在表面和大部分的流体，其中的e-折叠尺度的倏逝垂直剖面的特征波数。为了聚焦导致破碎的波包，我们观察到一个附加的漂移，可以是十倍以上的经典斯托克斯漂移的非破碎包在表面上，而破碎流体的初始深度与破碎时的波高成比例。我们发现破裂诱导的拉格朗日输运与破裂强度成比例。一个简单的缩放参数提出来描述这种增加的漂移，并发现是一致的直接数值模拟。上层海洋过程的应用进行了讨论。
The Lagrangian transport due to non-breaking and breaking focusing wave packets is examined. We present direct numerical simulations of the two-phase air-water Navier-Stokes equations describing focusing wave packets, investigating the Lagrangian drift by tracking tracer particles in the water before, during and after the breaking event. The net horizontal transport for non-breaking focusing packets is well described by the classical Stokes drift, both at the surface and in the bulk of the fluid, where the e-folding scale of the evanescent vertical profile is given by the characteristic wavenumber. For focusing wave packets that lead to breaking, we observe an added drift that can be ten times larger than the classical Stokes drift for a non-breaking packet at the surface, while the initial depth of the broken fluid scales with the wave height at breaking. We find that the breaking induced Lagrangian transport scales with the breaking strength. A simple scaling argument is proposed to describe this added drift and is found to be consistent with the direct numerical simulations. Applications to upper ocean processes are discussed.