Particle dispersion by random waves in rotating shallow water
Particle dispersion by random waves in rotating shallow water
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DOI：
10.1017/s0022112009991091
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发表时间：
2009-11-10
影响因子：
3.7
通讯作者：
Holmes-Cerfon, Miranda
中科院分区：
文献类型：
--
作者：
Buehler, Oliver;Holmes-Cerfon, Miranda
我们提出了由于旋转浅水系统中随机波引起的波浪诱导粒子色散的理论和数值研究，作为正在进行的海洋粒子色散研究的一部分。具体地说，在Taylor （Proc. long）的意义上，有效粒子扩散系数。数学。Soc。，第20卷，1921年，第196页)计算了一个小振幅波场的模拟为平稳均匀各向同性高斯随机场，其频谱有界远离零。在这种情况下，序阶扩散率主要取决于线性速度场的非线性二阶修正，这可以使用波均相互作用理论的方法计算。导出了有效扩散系数的封闭解析表达式，并通过蒙特卡罗数值模拟进行了仔细的验证。主要结论是：浅水中的科里奥利力总是降低粒子的有效扩散系数，在强旋转极限下，二级粒子流存在特殊的窒息效应。
We present a theoretical and numerical study of wave-induced particle dispersion due to random waves in the rotating shallow-water system, as part of an ongoing study of particle dispersion in the ocean. Specifically, the effective particle diffusivities in the sense of Taylor (Proc. Lond. Math. Soc., vol. 20, 1921, p. 196) are computed for a small-amplitude wave field modelled as a stationary homogeneous isotropic Gaussian random field whose frequency spectrum is bounded away from zero. In this case, the leading-order diffusivity depends crucially on the nonlinear, second-order corrections to the linear velocity field, which can be computed using the methods of wave-mean interaction theory. A closed-form analytic expression for the effective diffusivity is derived and carefully tested against numerical Monte Carlo simulations. The main conclusions are that Coriolis forces in shallow water invariably decrease the effective particle diffusivity and that there is a peculiar choking effect for the second-order particle flow in the limit of strong rotation.