A Parameterization with a Constrained Potential Energy Conversion Rate of Vertical Mixing Due to Langmuir Turbulence
A Parameterization with a Constrained Potential Energy Conversion Rate of Vertical Mixing Due to Langmuir Turbulence
复制标题
朗缪尔湍流垂直混合势能转换率约束的参数化
DOI：
10.1175/jpo-d-18-0258.1
复制
发表时间：
2019
影响因子：
3.5
通讯作者：
Qing Li
中科院分区：
文献类型：
--
作者：
B. Reichl;Qing Li
本文提出了一种新的海洋表面边界层湍流混合参数化方法，其中包括Langmuir湍流的影响。这种新的参数化建立在最近的一项研究（Reichl和Hallberg 2018，以下简称RH18）的基础上，该研究预测了由剪切和对流湍流驱动的湍流混合对抗稳定分层的可用能量。为了研究Langmuir湍流在RH18框架中的作用，我们利用了一系列先前发表的大涡模拟（LES）实验（Li和Fox-Kemper 2017，以下为LF17）在不同理想强迫条件下有无Langmuir湍流的数据。我们发现RH18的参数化能够再现非Langmuir情况下LES模拟的混合，但不能再现Langmuir情况下的混合。因此，我们利用LES数据研究了在Langmuir湍流存在下夹带层内综合垂直浮力通量的增强。在RH18框架中引入了一个额外的因子来捕捉由于朗缪尔湍流而增强的混合。这一附加因子取决于表层平均朗缪尔数，在存在破坏稳定的表面浮力通量的情况下减少。结果表明，在RH18 OSBL湍流混合参数化框架中加入该因子可以捕捉到Langmuir湍流在LES中的模拟效应，可用于模拟Langmuir湍流在气候模拟中的影响。将这种新的参数化与LF17引入的基于kpp的Langmuir夹带参数化进行了比较，并详细探讨了差异。
In this study we develop a new parameterization for turbulent mixing in the ocean surface boundary layer (OSBL), including the effect of Langmuir turbulence. This new parameterization builds on a recent study (Reichl and Hallberg 2018, hereafter RH18), which predicts the available energy for turbulent mixing against stable stratification driven by shear and convective turbulence. To investigate the role of Langmuir turbulence in the framework of RH18, we utilize data from a suite of previously published large-eddy simulation (LES) experiments (Li and Fox-Kemper 2017, hereafter LF17) with and without Langmuir turbulence under different idealized forcing conditions. We find that the parameterization of RH18 is able to reproduce the mixing simulated by the LES in the non-Langmuir cases, but not the Langmuir cases. We therefore investigate the enhancement of the integrated vertical buoyancy flux within the entrainment layer in the presence of Langmuir turbulence using the LES data. An additional factor is introduced in the RH18 framework to capture the enhanced mixing due to Langmuir turbulence. This additional factor depends on the surface-layer averaged Langmuir number with a reduction in the presence of destabilizing surface buoyancy fluxes. It is demonstrated that including this factor within the RH18 OSBL turbulent mixing parameterization framework captures the simulated effect of Langmuir turbulence in the LES, which can be used for simulating the effect of Langmuir turbulence in climate simulations. This new parameterization is compared to the KPP-based Langmuir entrainment parameterization introduced by LF17, and differences are explored in detail.
影响因子：
3.5
作者：
Grant, Alan L. M.;Belcher, Stephen E.
通讯作者：
Belcher, Stephen E.
斯托克斯漂移衰变尺度对朗缪尔湍流的影响
影响因子：
3.5
作者：
Kukulka, Tobias;Harcourt, Ramsey R.
通讯作者：
Harcourt, Ramsey R.
影响因子：
5.2
作者：
Belcher, Stephen E.;Grant, Alan L. M.;Polton, Jeff A.
通讯作者：
Polton, Jeff A.