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

俄勒冈州立大学ATM-9807768Mahrt，拉里·J·俄勒冈州立大学标题：非常稳定的边界层这个项目的目的是提高我们对当靠近地面的大气层非常稳定时，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。在这种情况下，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用于白天条件的理论。在白天，地面加热会导致地面附近的空气变得不稳定，导致对流、充分发展的湍流、温度、风速和湿度的可预测轮廓，以及因此可预测的垂直热量和水蒸气通量。但在夜间，地表寒冷，空气稳定，湍流通常是间歇性的，由垂直风切变与地形引起的排水气流有关。方法是分析来自12个不同野外计划的现有数据，这些数据代表不同类型的地形和气候条件，以确定用风速、地表温度和其他已知量来表示通量的新方法。这项研究将把观测结果与现有的理论进行比较，寻找改进理论的方法，并评估由升高的剪切层引起的湍流在将材料输送到地面上的重要性。研究的结果将是改进的非常稳定的边界层公式，以供大规模使用