Numerical Modeling of Mesoscale Airflow over Mountains

山区中尺度气流的数值模拟

• 批准号: 9218376
• 负责人: Dale Durran
• 金额: $ 32.3万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-03-15 至 1996-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9218376&HistoricalAwards=false
• 关键词: Numerical; Modeling; Mesoscale; Airflow; over

Accurate weather forecasting in the vicinity of major mountain ranges is an extremely difficult meteorological problem. Interactions between large-scale weather systems and mountainous regions often spawn complex mesoscale weather patterns. Efforts to forecast the development of these weather patterns are limited by deficiencies in understanding of the physical processes governing mesoscale circulations in complex terrain. Additionally, mesoscale orographic effects also influence the global circulation through the action of gravity wave drag. Errors in the parameterization of gravity wave drag in global scale modes are believed to be a major source of error in extended range forecasts. Under previously supported research on this topic the Principal Investigator has found that vertically propagating mountain waves appear to be not as sensitive to the asymmetry of the underlying terrain as previously thought. Using free slip conditions, he has found that maximum lee slope winds also are not sensitive to asymmetry of the terrain. When surface friction is included, however, sensitivity to terrain is enhanced, but the primary regulator of maximum winds appears to be the steepness of the lee slope. The Principal Investigator will continue this line of research with the ultimate goal of improving weather forecasts for locations in the vicinity of mountains and to improve extended range forecasts and climate models. The major areas of concentration are: investigation of airflow in complex three-dimensional topography with emphasis on mountain barriers with and without mountain gaps, and isolated mountain peaks; study of momentum fluxes in orographically forced gravity waves and the interactions of these waves with the larger scale flow through gravity wave drag.

主要山脉附近的准确天气预报 测距是一个极其困难的气象问题。 大尺度天气系统和山区气候系统之间的相互作用 区域往往产生复杂的中尺度天气模式。 努力 预测这些天气模式的发展受到以下因素的限制 缺乏对物理过程的理解 复杂地形中尺度环流 此外，中尺度 地形效应也通过影响全球环流 重力波阻力的作用。 参数化中的错误 全球尺度模式中的重力波阻力被认为是一个主要的 扩展范围预测的误差来源。 根据以前支持的关于这一主题的研究， 首席研究员发现垂直传播 山波似乎不敏感的不对称性， 如之前所想的那样， 使用自由滑动 条件下，他发现最大背风坡风也不是 对地形的不对称性很敏感 当表面摩擦力为 包括，然而，对地形的敏感性增强，但 最大风速的主要调节器似乎是 背风坡 主要研究者将继续这一研究方向 最终目标是改善地点的天气预报 在山区附近， 预测和气候模型。 主要集中领域 是：调查气流在复杂的三维 地形，重点是山区障碍， 山坳和孤立的山峰;动量的研究 地形强迫重力波通量及其相互作用 这些波中较大尺度的流通过重力波 阻力