Abstract In this study, we expand previous large eddy simulation (LES) modeling investigations of Langmuir turbulence (LT) to real ocean conditions using field observations collected under the multi-platform field campaign “Coupled Air–Sea Processes and Electromagnetic (EM) ducting Research (CASPER-East)”. The measurement site has strong local variabilities of temperature and salinity and experienced large variations in wind forcing and several cooling events. Although LT enhances the turbulence in the water column and deepens the mixed layer during most of the simulation period, being consistent with previous studies, strong reduction of turbulent kinetic energy (TKE) in the mixed layer is observed in the simulation with Stokes drift compared to that without Stokes drift during a short period. Analysis of the meteorological forcing and the TKE budget have revealed that in the circumstance of swell dominated wave fields with young wind seas, the presence of Stokes drift reduces shear production more than the Stokes production it generates, and a reduction of total TKE in the mixed layer may be expected whether or not the Stokes drift is aligned with the wind. Weak reduction of TKE due to the inclusion of Stokes drift is also observed beneath the mixed layer during a cooling event possibly due to the fact that the upwelling associated with Langmuir circulation at the base of the mixed layer counteracts on the downwelling associated with the deep convection and reduces the total turbulence level in the water column. While both resolved Reynold stresses and the bulk eddy viscosity decrease with the increase of wind-wave misalignment angle θ w w and become smaller than that in the case without Stokes drift when θ w w exceed 60°, the subgrid scale (SGS) part of the momentum flux increases with the increase of θ w w , suggesting that the LES solutions in cases with large wind-wave misalignment become more sensitive to the SGS models used and need to be dealt with caution.

中文翻译：

---

复杂真实海洋和气象强迫下朗缪尔湍流的影响

摘要 在这项研究中，我们使用在多平台野外活动“耦合空气-海洋过程和电磁 (EM) 管道研究”下收集的现场观测，将先前对朗缪尔湍流 (LT) 的大涡模拟 (LES) 建模研究扩展到真实的海洋条件。 （卡斯珀东）”。测量地点具有强烈的局部温度和盐度变化，并且经历了风力和几次冷却事件的巨大变化。尽管 LT 在大部分模拟期间增强了水柱中的湍流并加深了混合层，但与先前的研究一致，与 Stokes 漂移相比，在模拟中观察到混合层中的湍流动能 (TKE) 强烈降低在短时间内没有斯托克斯漂移。对气象强迫和 TKE 收支的分析表明，在涌浪主导波场和年轻风海的情况下，斯托克斯漂移的存在减少了剪切产生，而不是它产生的斯托克斯产生，并且混合中总 TKE 的减少无论斯托克斯漂移是否与风对齐，都可以预期层。在冷却事件期间，在混合层下方也观察到由​​于包含斯托克斯漂移而导致 TKE 的弱减少，这可能是因为与混合层底部朗缪尔环流相关的上升流抵消了与深对流相关的下降流并降低水柱中的总湍流水平。