Five planetary-boundary-layer parametrizations of the Weather Research and Forecasting model are compared with respect to their ability to simulate the very stable and the weakly stable regimes of the stable boundary layer. This is performed for single column models where the large-scale mechanical forcing is represented by geostrophic wind speeds ranging from 0.5 to 12 m s-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {s}^{-1}$$\end{document}. The performance of the models is assessed by contrasting the relationships they produce between the turbulence velocity scale and the mean wind speed, between potential temperature gradient and the mean wind speed, and between the flux and gradient Richardson numbers. The level-2.5 Mellor–Yamada–Nakanishi–Niino parametrization simulates the very stable regime the best, mainly because its heat eddy diffusivity decreases with respect to the momentum eddy diffusivity as the stability increases, while the same is not true for the other parametrizations considered.

中文翻译：

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天气研究与预报模型中不同湍流参数如何再现两制态稳定边界层？

天气研究和预测模型的五个行星边界层参数化在模拟稳定边界层的非常稳定和弱稳定状态的能力方面进行了比较。这是针对单列模型执行的，其中大规模机械强迫由地转风速范围从 0.5 到 12 m s-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{ amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {s}^{-1}$ $\end{文档}。模型的性能是通过对比它们在湍流速度尺度和平均风速之间、潜在温度梯度和平均风速之间产生的关系来评估的，以及通量和梯度理查森数之间。2.5 级 Mellor-Yamada-Nakanishi-Niino 参数化模拟了非常稳定的状态，这主要是因为随着稳定性的增加，其热涡流扩散率相对于动量涡流扩散率会降低，而其他考虑的参数化则并非如此.