川南森林湍流通量质量评价及贡献区分析  

Turbulent Flux Mass Evaluation and Contribution Region Analysis of the Underlying Surface in Southern Sichuan Forest

作　　者：范德民 张宇 苏有琦 张茜 FAN Demin;ZHANG Yu;SU Youqi;ZHANG Qian(College of Atmospheric Sciences,Chengdu University of Information Technology/Chengdu Plain Urban Meteorology and Environment Sichuan Provincial Field Scientific Observation and Research Station,Chengdu 610225,Sichuan,China)

机构地区：[1]成都信息工程大学大气科学学院/成都平原城市气象与环境四川省野外科学观测研究站,四川成都610225

出　　处：《高原气象》2024年第1期227-240,共14页Plateau Meteorology

基　　金：国家自然科学基金项目(42275131)。

摘　　要：由于通量观测容易受复杂下垫面和仪器精度影响,需基于涡动相关系统观测原理对原始数据进行严格的预处理和质量控制。本研究选用2021年5-12月来自于川南地区四峨山森林下垫面的涡动相关系统的湍流观测资料,观测设备架设在不同高度包括粗糙副层内、粗糙副层与常通量层边界以及常通量层内。利用上述观测数据量化了两种坐标旋转方案下湍流通量计算结果的差异性,并结合湍流稳定性和发展性检验对通量资料序列进行了质量评价,最后分析了不同大气稳定度和不同观测高度下足迹函数所表示的通量贡献区域变化范围。结果表明:二次坐标旋转校正后的通量数据大于平面拟合后的数据,且两者的校正差距随观测高度的增加而增大。从通量数据质量等级分布特征来看,感热通量数据质量优于潜热通量及CO_(2)通量,且低层数据质量优于高层。38 m和56 m观测高度主风向在东北-西北方向上呈现昼夜相反的变化,其中5-9月尤为明显。不同大气稳定度下的通量贡献范围存在一定的差异,在大气稳定条件下,38 m观测高度的通量信息80%来源于距离观测塔西侧50~1400 m区域;在大气不稳定条件下,通量测量的源区水平范围在0~500 m之间。在56 m观测高度且大气稳定条件下,通量贡献80%的源区边界距测点可达1500 m;不稳定条件下,源区范围在0~750 m之间。冬夏两季在稳定大气条件下贡献区范围有明显差异,在38 m观测高度上,夏、冬季节最大湍流通量信息分别来于1320 m、 700 m。在相同大气稳定度下,通量贡献区的分布受观测高度的影响,56 m观测高度通量源区大于38 m的通量源区。As flux observations are susceptible to complex underlying surface and instrument accuracy,rigorous pre-processing and quality control of the raw data is required based on the principles of the Eddy Covariance system observations.In this study,turbulence observations of the eddy-related system from May to December 2021 were selected from the Si'e Mountain Forest in the southern Sichuan region,and the observations were set up at different heights,including within the rough sublayer,at the boundary between the rough sublayer and the normal flux layer,and within the normal flux layer.The variability of the turbulent flux calculations under the two coordinate rotation schemes is quantified by the above observations and the quality of the flux data series is evaluated in conjunction with turbulence stability and development tests.Finally,the range of variability of the flux contribution region represented by the footprint function is analyzed for different atmospheric stability and different observation heights.The results show that the flux data corrected by the double coordinate rotation are larger than those from the plane fit and that the difference in correction between the two is significant with increasing observation height.Regarding flux data quality features,sensible heat flux data quality is better than latent heat flux and CO_(2) flux,and lower data quality is better than higher data quality.At observation heights of 38 m and 56 m,the dominant wind direction showed opposite day and night variations in northeast-northwest direction,especially from May to September.There is some variation in the range of flux contributions at different levels of atmospheric stability.Under atmospheric stability,80%of the flux information at 38 m altitude comes from the area 50~1400 m west of the tower;under atmospheric instability,the horizontal range of the source area for flux measurements is between 0 and 500 m.At an observation height of 56 m and under stable atmospheric conditions,the boundary of the source area with 80

关 键 词：湍流通量 质量评价 通量贡献区 森林下垫面 

分 类 号：P413[天文地球—大气科学及气象学]