Multi-Point Monin-Obukhov Similarity and Spectral Dynamics in the Convective Atmospheric Surface Layer

对流大气表层的多点Monin-Obukhov相似性和光谱动力学

• 批准号: 1561190
• 负责人: Chenning Tong
• 金额: $ 36.63万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1561190&HistoricalAwards=false
• 关键词: Multi; Point; Monin; Obukhov; Similarity

The research focuses on the Monin-Obukhov similarity hypothesis, which is the theoretical foundation for understanding the surface layer of the atmospheric boundary layer (ABL). The hypothesis has been used successfully to scale many statistics (e.g., those containing the vertical velocity) in the surface layer. However, it fails to scale some other important statistics, such as the horizontal velocity variances and the large-scale horizontal velocity spectra in the convective surface layer.The research will provide a more universal scaling framework for the influence of shear and buoyancy on the surface layer turbulence, termed multi-point Monin-Obukhov similarity (MMO). In the research, the PI will systematically investigate MMO through its spectral predictions and the spectral dynamics in the surface layer. Systematical tests of the predicted large-scale velocity and temperature spectra using high-resolution large-eddy simulation (LES) fields will be conducted. The research will be conducted in collaboration with Dr. Martin Otte at Computer Science Corporation (CSC), a research firm contracting with the Environmental Protection Agency.Intellectual Merit:The research addresses the critical issue of Monin-Obukhov similarity of the atmospheric surface layer. It is expected to further validate MMO through its prediction of the turbulence spectra and cospectra; it will provide an important understanding of the physical basis for MMO. Due to the central role of the Monin-Obukhov similarity in our understanding of the surface layer dynamics, the research on MMO will provide a new framework for analyzing and understanding the surface layer turbulence, and will have a strong impact on the understanding and modeling of the ABL in general.Broader Impacts:The research has broader impacts in several areas. It will provide education and research opportunities for graduate and undergraduate students. Improved understanding of the surface layer turbulence and the ABL in general will be of importance to developing predictive models for atmospheric dispersion and diffusion, weather forecasting, atmospheric chemistry, wind energy, and land-atmosphere exchange. The modeling approach will also be important for modeling boundary layers with a strong pressure gradient (e.g., curved boundary layers) in the atmosphere and in engineering flows. Advances in these areas will benefit the environment and society.

莫宁-奥布霍夫相似性假说是理解大气边界层近地层的理论基础。该假设已成功地用于衡量许多统计数据（例如，包含垂直速度的那些）。然而，该方法未能对对流近地层中的水平速度方差和大尺度水平速度谱等重要统计量进行标度，这将为研究切变和浮力对近地层湍流的影响提供一个更为通用的标度框架，即多点Monin-Obukhov相似性（MMO）。 在研究中，PI将通过其光谱预测和表面层的光谱动力学系统地研究MMO。将使用高分辨率大涡模拟（LES）场对预测的大尺度速度和温度谱进行系统测试。该研究将与计算机科学公司（CSC）的Martin Otte博士合作进行，CSC是一家与环境保护局签订合同的研究公司。智力优势：该研究解决了大气表层的Monin-Obukhov相似性的关键问题。通过对湍流谱和共谱的预测，有望进一步验证MMO的有效性，为MMO的物理基础提供重要的认识。由于Monin-Obukhov相似性在我们理解近地面层动力学中的核心作用，MMO的研究将为分析和理解近地面层湍流提供一个新的框架，并将对ABL的理解和建模产生强烈的影响。它将为研究生和本科生提供教育和研究机会。提高对近地面层湍流和大气边界层的认识，对于发展大气扩散和扩散、天气预报、大气化学、风能和陆-气交换的预测模型具有重要意义。建模方法对于建模具有强压力梯度的边界层（例如，弯曲边界层）在大气和工程流中。这些领域的进步将有利于环境和社会。