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大模拟的网格分辨率对福恩-冷池相互作用的影响
1Department of Atmospheric and Cryospheric Sciences University of Innsbruck Innsbruck Austria.
概括
数字模拟显示,更高的模型分辨率,特别是在100米左右,显著改善了模拟复杂地形中风风的冷空池流侵蚀的模拟. 这种增强的分辨率更好地捕捉流和不稳定性,这对于准确的天气预报至关重要.
科学领域:
- 大气科学 大气科学
- 气象学 天气学
- 计算流体动力学的流体动力学.
背景情况:
- 阿尔卑斯山山谷的冷空气池 (CAPs) 受风的影响,这是一种涉及强风剪切和流的现象.
- 了解CAPs的动荡侵蚀对于在山区准确预报天气至关重要.
研究的目的:
- 评估横向和垂直模型分辨率对模拟波性侵蚀CAPs的波风的影响.
- 在数值天气模型中调查流的"灰色区域"及其对电网间距的敏感性.
主要方法:
- 使用天气研究和预测 (WRF) 模型在大模拟 (LES) 和大尺度模拟模式中的数值模拟.
- 测试各种水平网格间距 (1公里,200米,40米,13.33米) 和垂直分辨率.
- 通过剪流和凯尔文-赫尔姆霍尔茨 (K-H) 不稳定性分析流的产生.
主要成果:
- 中等尺度模拟 (1公里) 无法准确地表示CAP发展和K-H不稳定性.
- 即使使用较粗的网格 (200米),LES模拟也开始解决KH不稳定性,改善风形状.
- 更细的LES网格 (40米,13.33米) 提供了更现实的流,但对平均数量的影响最小.
- 增加的垂直分辨率有利于上方的foehn喷气;增加的水平分辨率改善了foehn-CAP接口的流.
结论:
- 100米) 的水平模型分辨率为模拟风-CAP相互作用和流提供了显著的好处.
- 即使是40米的分辨率也不能完全捕捉到能量布,这表明需要更细的网格来进行详细的流分析.
- 改进的分辨率增强了流和不稳定的表示,从而在复杂的地形中更好地进行数值天气预报.
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