基于通量观测矩阵的地表能量平衡闭合研究

项目名称： 基于通量观测矩阵的地表能量平衡闭合研究

项目编号： No.41301355

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 徐自为

作者单位： 北京师范大学

项目金额： 25万元

中文摘要： "能量平衡不闭合"是涡动相关方法测量地表水热通量过程中普遍存在的问题，该问题的存在严重制约了地表水热通量遥感估算模型和陆面过程模式的发展。本项目选取黑河流域中、下游绿洲-荒漠生态系统及林地-农田-裸地混合下垫面为试验区，基于试验区内密集布点的矩阵式通量（涡动相关仪、大孔径闪烁仪）和自动气象站观测，研究通量、气象观测数据的处理方法，以获取质量可靠的观测数据集；度量矩阵中每台涡动相关仪观测数据的不确定性；准确计算矩阵中每台涡动相关仪的能量平衡闭合率及其空间代表性；应用小波分析方法分离湍流数据的高、低频涡旋，并定量计算其在单时次内通量的贡献率；研究计算"面积平均通量"的不同聚合方法，分析'面'上能量平衡闭合状况。本项目旨在基于矩阵式观测技术分析复杂下垫面上引起涡动相关仪能量平衡不闭合的原因，为保证遥感估算模型和陆面过程模式验证结果的有效性提供科学依据。

中文关键词： 涡动相关仪；能量平衡闭合；数据处理；异质性；

英文摘要： Energy imbalance is a universal existence problem during measuring water vapor and heat flux using eddy covariance system (EC). This problem has impeded the development of remote sensing model in estimating water vapor and heat flux and land surface model seriously. The study area of this project is in an oasis-desert system and forest-cropland-bare soil land in the middle and lower reach of Heihe River Basin. Based on the intensive matrix measurements of flux instruments (EC, large aperture scintillometer (LAS)) and automatic weather station (AWS), the processing methods of EC,LAS, and AWS data will be studied, and reliable data set could be acquired. The uncertainty of each EC in the matrix area will be assessed; the energy balance closures will be exactly calculated, and we will also calculate the footprint of EC and LAS. The wavelet analysis method is adopted to separate the low and high frequencies part of the turbulence, and quantitative analysis of its contribution will be discussed. Different aggregation methods will be investigated to derive the area averaged flux, and further analyzing on the regional energy balance closure will be studied. The purpose of this project is investigating the causes of energy imbalance of EC using matrix observation technique under complex underlying surface,and the findin

英文关键词： Eddy covariance system；Energy balance closure；Data processing；Heterogeneous；