Experimental Studies of Turbulence in the Surface Layer: Phase II

表层湍流的实验研究：第二阶段

• 批准号: 8714025
• 负责人: Paul Frenzen
• 金额: $ 15.23万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-10-15 至 1990-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8714025&HistoricalAwards=false
• 关键词: Experimental; Studies; Turbulence; Surface; Layer

The object of this research is a systematic evaluation of sources and sinks of turbulent kinetic energy in the atmospheric surface layer. Effects of stability on the normalized terms of the turbulent energy equation (the so-called "phi functions") are being investigated in a graduated series of comparatively small field experiments. The particular forms of and the empirical constants in relations for these functions now commonly used to parameterize the lower boundary layer remain uncertain because of contradictory results of subsequent experiments and incomplete investigation of the effects of stability. This experiment will measure wind profiles, turbulence spectra, surface thermal energy balances, and Bowen ratios in order to evaluate the effects of moderate departures from neutrality upon (1) the rates at which turbulence is produced by wind shear and buoyancy, (2) the turbulence dissipation rate, (3) the net rate at which energy is locally gained or lost by the sum of the divergence terms. To obtain this budget data, additional measurements will be added: the depth of the mixed layer will be monitored acoustically and the vertical turbulent flux of turbulent energy will be measured by two levels by eddy correlation. All field experiments will be conducted over extensive cropped surfaces of uniform roughness. Professor Frenzen is well qualified to make these measurements; he has considerable experience in previous field measurements especially in the use of his unique low-inertia anemometers.

本研究的目的是对来源进行系统评估 大气表面的湍流动能 层. 稳定性对湍流归一化项的影响 能量方程（所谓的“phi函数”）被 在一系列相对较小的领域进行研究 实验 的特殊形式和经验常数 这些函数的关系现在通常用于参数化 下边界层仍然不确定，因为矛盾 随后的实验结果和不完整的调查， 稳定性的影响。 这个实验将测量风廓线，湍流谱， 表面热能平衡和Bowen比， 评估适度偏离中性对（1）的影响 风切变和浮力产生湍流的速率， (2)湍流耗散率，（3）能量的净速率 是局部地由发散项的和获得或损失。 到 获得此预算数据后，将添加其他测量： 混合层的深度将被声学监测， 湍流能量的垂直湍流通量将由两个 涡动相关水平。 所有的现场实验都将在 在均匀粗糙的大面积裁剪表面上。 Frenzen教授完全有资格进行这些测量; 他在以前的实地测量中有相当丰富的经验， 特别是在使用他独特的低惯性风速计。