The Very Stable Boundary Layer

非常稳定的边界层

• 批准号: 9807768
• 负责人: Larry Mahrt
• 金额: $ 39.25万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9807768&HistoricalAwards=false
• 关键词: Very; Stable; Boundary; Layer

AbstractATM-9807768Mahrt, Larry J.Oregon State UniversityTitle: The Very Stable Boundary LayerThe purpose of this project is to improve our understanding of the exchange of heat, moisture, momentum, and contaminants between the earth's surface and the lower atmosphere when the atmospheric layer near the ground is extremely stable. In these conditions, the variation of the wind with height and time and the vertical transport of heat and other material by the atmosphere do not conform to the theories appropriate for daytime conditions. During the day surface heating causes the air next to the ground to become unstable, leading to convection, well developed turbulence, predictable profiles of temperature, wind velocity, and humidity, and therefore predictable vertical fluxes of heat and water vapor. But at night the surface is cold, the air stable, and the turbulence often intermittent and caused by vertical wind shear associated with terrain-induced drainage flows. The approach is to analyze existing data from twelve different field programs, which represent different kinds of terrain and climatic conditions, to determine new ways to express the fluxes in terms of wind speed, surface temperature, and other known quantities. The study will compare the observations with existing theories, seek ways of improving the theories, and assess the importance of turbulence induced by elevated shear layers in transporting material down to the ground. The result of the research will be an improved formulation of the very stable boundary layer for use in large scale

摘要ATM-9807768Mahrt，拉里·J.俄勒冈州立大学标题：非常稳定的边界层该项目的目的是提高我们对当大气层接近时地球表面和低层大气之间的热量、水分、动量和污染物交换的理解。地面极其稳定。 在这些条件下，风随高度和时间的变化以及大气对热量和其他物质的垂直输送不符合适合白天条件的理论。 白天，地表加热导致地面附近的空气变得不稳定，导致对流、发展良好的湍流、可预测的温度、风速和湿度分布，从而产生可预测的热和水蒸气垂直通量。 但在夜间，地表寒冷，空气稳定，湍流经常是间歇性的，由与地形引起的排水流相关的垂直风切变引起。 该方法是分析来自十二个不同现场项目的现有数据，这些数据代表不同类型的地形和气候条件，以确定用风速、表面温度和其他已知量来表达通量的新方法。 该研究将把观察结果与现有理论进行比较，寻求改进理论的方法，并评估高剪切层引起的湍流在将物质输送到地面时的重要性。 研究结果将是用于大规模应用的非常稳定边界层的改进公式