黄土高原半干旱区复杂地形条件下稳定边界层湍流特征研究

项目名称： 黄土高原半干旱区复杂地形条件下稳定边界层湍流特征研究

项目编号： No.41475008

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 张镭

作者单位： 兰州大学

项目金额： 96万元

中文摘要： 正确认识大气边界层湍流特征是陆气相互作用、气候变化、环境评估等研究与应用的重要基础。目前对不稳定边界层湍流的认识较成熟，而受理论基础和观测条件制约，稳定边界层湍流研究不足。欲深入研究稳定边界层湍流，需进行高精度有代表性的观测。本项目拟采用涡动相关系统、气象要素梯度观测、大孔径闪烁仪等多种先进观测仪器，在黄土高原半干旱区复杂地形典型站点，开展大气湍流观测；改进稳定边界层湍流资料的处理方法，评估动量、感热、潜热和二氧化碳通量观测的不确定性；研究不同尺度大气运动对通量输送的贡献；分析不同背景流场时湍流特征，讨论相似理论在复杂地形稳定边界层的适用性，改进该区域稳定边界层湍流参数化方案。为研究区域陆气相互作用及其对气候变化的响应、检验卫星遥感反演提供数据支撑；增进对复杂地形稳定边界层湍流机理的认识，提高大气数值模式的模拟能力，具有重要的科学意义。

中文关键词： 观测实验；陆气相互作用；非平稳运动；相似理论；湍流参数化

英文摘要： Accurate determination of turbulence in the boundary layer is one of the basic frameworks in the fields of land-atmosphere interactions, climate change, and environment assessment, et al. It is rather mature under unstable stratification in understanding the turbulence, while the research in a stable boundary layer is more difficult and unpredictable, restricted by the lack of reliable theoretical and observation. To further study of turubulence in a stable boundary layer over complex terrain, high quality observation data is needed. With this consideration, this project will execute field experiments at representative sites on the complex terrain in the semiarid region of the Loess Plateau, using eddy covariance system (EC), boundary layer meteorological measurements system, and large aperture scintillometer. Then the project will try to establish the processing methods to compute turbulent fluxes with EC data in stable boundary layer over complex terrain; assess the uncertainties in fluxes of momentum, sensible heat, latent heat and carbon dioxide; analyses the contributions of movements with various scales to the overall flux; investigate the characteristics of turbulence under various types of background flow fields; examine the validity of the Monin-Obukhov similarity theory (MOST) in stable boundary layer over complex terrain, and improve the turbulence parameterization scheme. This project surely has important scientific senses on the researches of regional land-atmosphere interactions and its response to the climate change, on understanding turbulence mechanism in stable boundary layer over complex terrain, and on improving the parameterization schemes of the atmospheric boundary layer in numerical models.

英文关键词： Field experiment;Land-atmosphere interactions;Non-stationary motions;Similarity theory;Turbulence parameterization