Ekman Transport in Balanced Currents with Curvature
Ekman Transport in Balanced Currents with Curvature
复制标题
DOI：
10.1175/jpo-d-16-0239.1
复制
发表时间：
2017-05
影响因子：
3.5
通讯作者：
J. Wenegrat;L. Thomas
中科院分区：
文献类型：
--
作者：
J. Wenegrat;L. Thomas
Ekman输运是与作用在海洋表面的风应力有关的水平质量输运，它被海流的涡度所改变，从而产生所谓的非线性Ekman输运。本文扩展了以前的工作在这个问题上推导出的非线性Ekman运输有效的曲率电流，如曲折的射流或圆形涡，并与Rossby数接近统一的流量的解决方案。倾斜的水平涡度的Ekman流的平衡电流修改海洋响应表面强迫，这样，领先的顺序，风平行于流驱动Ekman运输，仅取决于垂直相对涡度的剪切涡度分量，而横向流风驱动运输依赖于曲率涡度。因此，在平衡流场中的曲率导致Ekman输运，这不同于在直流假设下推导出的先前公式。值得注意的是，理论上，
AbstractEkman transport, the horizontal mass transport associated with a wind stress applied on the ocean surface, is modified by the vorticity of ocean currents, leading to what has been termed the nonlinear Ekman transport. This article extends earlier work on this topic by deriving solutions for the nonlinear Ekman transport valid in currents with curvature, such as a meandering jet or circular vortex, and for flows with the Rossby number approaching unity. Tilting of the horizontal vorticity of the Ekman flow by the balanced currents modifies the ocean response to surface forcing, such that, to leading order, winds parallel to the flow drive an Ekman transport that depends only on the shear vorticity component of the vertical relative vorticity, whereas across-flow winds drive transport dependent on the curvature vorticity. Curvature in the balanced flow field thus leads to an Ekman transport that differs from previous formulations derived under the assumption of straight flows. Notably, the theory al...