标题： 风对海洋中尺度和次中尺度作用的理论 显示英文标题

标题： A Theory for Wind Work on Oceanic Mesoscales and Submesoscales

摘要： 以往的研究主要集中在风应力与相对于海洋速度的风速成正比，这会在风应力中诱导出一个极性与海洋中尺度涡度相反的旋度，从而导致净负的风功。 然而，在理解风对海洋做功如何与海洋的涡动和应变运动相关联方面，仍存在根本性的空白。 虽然可以推导出海洋涡度和应变的收支平衡，但这些并不能提供由风应力输送到涡动和应变运动中的能量。 一种偶尔出现的误解是，亥姆霍兹分解可以将涡度从应变中分离出来，而后者被错误地认为完全是由潜在流（负责发散运动）引起的。 事实上，应变也是无散（或无源）流的重要组成部分，包括在地转平衡中的海洋中尺度涡旋，其中以应变为主的区域占总动能（KE）的大约一半。 目前尚不存在一个流体力学框架能够将力注入动能与这种能量如何沉积到涡动和应变运动中联系起来。 在这里，我们展示了风平均来说在抑制应变运动方面的效果与抑制涡动运动的效果一样显著。 这是因为海洋应变会诱导出一种应变风应力梯度（WSG），这类似于海洋涡度在风应力中诱导出旋度。 仅由海洋诱导的WSG，无论是应变还是涡动，总是会减弱海洋洋流。 然而，我们的理论还揭示了风功的一个重要贡献来自固有的风梯度，其中主要成分是由于大气环流的盛行风。 我们发现，固有的WSG根据涡动和应变海洋流动的极性，会导致海洋天气不对称的能量化。 显示英文摘要

摘要： Previous studies focused primarily on wind stress being proportional to wind velocity relative to the ocean velocity, which induces a curl in wind stress with polarity opposite to the ocean mesoscale vorticity, resulting in net negative wind work. However, there remains a fundamental gap in understanding how wind work on the ocean is related to the ocean's vortical and straining motions. While it is possible to derive budgets for ocean vorticity and strain, these do not provide the energy channeled into vortical and straining motions by wind stress. An occasional misconception is that a Helmholtz decomposition can separate vorticity from strain, with the latter mistakenly regarded as being solely due to the potential flow accounting for divergent motions. In fact, strain is also an essential constituent of divergence-free (or solenoidal) flows, including the oceanic mesoscales in geostrophic balance where strain-dominated regions account for approximately half the KE. There is no existing fluid dynamics framework that relates the injection of kinetic energy by a force to how this energy is deposited into vortical and straining motions. Here, we show that winds, on average, are just as effective at damping straining motions as they are at damping vortical motions. This happens because oceanic strain induces a straining wind stress gradient (WSG), which is analogous to ocean vorticity inducing a curl in wind stress. Ocean-induced WSGs alone, whether straining or vortical, always damp ocean currents. However, our theory also reveals that a significant contribution to wind work comes from inherent wind gradients, a main component of which is due to prevailing winds of the general atmospheric circulation. We find that inherent WSGs lead to asymmetric energization of ocean weather based on the polarity of vortical and straining ocean flows.