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

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 hei