Explicit Numerical Diffusion in the WRF Model
Explicit Numerical Diffusion in the WRF Model
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DOI：
10.1175/2007mwr2100.1
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发表时间：
2007-11
影响因子：
3.2
通讯作者：
J. Knievel;G. Bryan;J. Hacker
中科院分区：
文献类型：
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作者：
J. Knievel;G. Bryan;J. Hacker
摘要在早期版本的天气研究和预报（WRF）模型的高级研究核心中，奇数阶平流方案中隐含的扩散有时不足以消除运动场中的噪声。当网格相对风速较低且分层接近中性或不稳定时，问题最严重，例如在弱强迫的白天边界层中，噪声可以增长，直到与模拟的物理现象竞争。这个问题的一个解决方案是显式的，六阶数值扩散方案，保持WRF模型的高有效分辨率，并使用通量限制器，以确保单调性。该计划，以及它是如何被添加到WRF模型，解释。该计划，然后证明在一个理想化的框架和模拟的盐风和湖风在西北犹他州。
Abstract Diffusion that is implicit in the odd-ordered advection schemes in early versions of the Advanced Research core of the Weather Research and Forecasting (WRF) model is sometimes insufficient to remove noise from kinematical fields. The problem is worst when grid-relative wind speeds are low and when stratification is nearly neutral or unstable, such as in weakly forced daytime boundary layers, where noise can grow until it competes with the physical phenomena being simulated. One solution to this problem is an explicit, sixth-order numerical diffusion scheme that preserves the WRF model’s high effective resolution and uses a flux limiter to ensure monotonicity. The scheme, and how it was added to the WRF model, are explained. The scheme is then demonstrated in an idealized framework and in simulations of salt breezes and lake breezes in northwestern Utah.