A modification of the classical Ekman model accounting for the Stokes drift and stratification effects
A modification of the classical Ekman model accounting for the Stokes drift and stratification effects
复制标题
考虑斯托克斯漂移和分层效应的经典 Ekman 模型的修改
DOI：
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发表时间：
2012
影响因子：
2.2
通讯作者：
A. Toompuu
中科院分区：
文献类型：
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作者：
J. Heinloo;A. Toompuu
本文讨论了考虑Stokes漂移和层结效应的经典Ekman海洋风海流模型的一个修正。该修正被配制为湍流力学的应用占速度波动流线的曲率效应。结果表明，类似的斯托克斯漂移效应，密度跃变层（密度跃层）的存在下，减少了转向的流速矢量在表面的风应力的方向。它还表明，在密度跃层的速度矢量的范数的减少，以及其旋转随深度小于在密度跃层附近的区域。如果忽略Stokes漂移和分层效应，模型将退化为经典的Ekman解，用有效粘性系数代替湍流剪切粘性系数。修正后的模型预测的速度的垂直分布进行了比较，在德雷克海峡和长期上层海洋研究（LOTUS）在北大西洋的速度测量数据。
A modification of the classical Ekman model of oceanic wind-driven currents including the Stokes drift and stratification effects is discussed. The modification is formulated as an application of turbulence mechanics accounting for the curvature effect of velocity fluctuation streamlines. It is shown that similar to the Stokes drift effect, the presence of a density jump layer (pycnocline) decreases the veering of the flow velocity vector at the surface from the direction of the wind stress. It is shown also that in the pycnocline the decrease of the norm of the velocity vector as well as its rotation with depth is smaller than in the regions adjacent to the pycnocline. If the Stokes drift and stratification effects are neglected, the model reduces to the classical Ekman solution with the coefficient of the turbulent shear viscosity replaced by an effective viscosity coefficient. The vertical distributions of velocity predicted by the modified model are compared with the velocity data measured in the Drake Passage and within the Long-Term Upper Ocean Study (LOTUS) in the North Atlantic.