Marginal Instability and the Efficiency of Ocean Mixing
Marginal Instability and the Efficiency of Ocean Mixing
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DOI：
10.1175/jpo-d-20-0083.1
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发表时间：
2020-08
影响因子：
3.5
通讯作者：
W. Smyth
中科院分区：
文献类型：
--
作者：
W. Smyth
地球物理流体中分层湍流的混合效率一直是有相当大争议的问题。几十年前，当经验知识稀缺时，设计了一个简单的参数化方法，效果非常好。参数化基于通量系数Γ具有均匀值0.2的假设。本文根据强迫分层剪切流的“边缘不稳定性”性质，对Γ = 0.2给出了物理解释，并通过检验不成立的情况，勾画了一条改进这一简单图象的途径。
The mixing efficiency of stratified turbulence in geophysical fluids has been the subject of considerable controversy. A simple parameterization, devised decades ago when empirical knowledge was scarce, has held up remarkably well. The parameterization rests on the assumption that the flux coefficient Γ has the uniform value 0.2. This note provides a physical explanation for Γ = 0.2 in terms of the “marginal instability” property of forced stratified shear flows, and also sketches a path toward improving on that simple picture by examining cases where it fails.