The Design and Application of CO2 Flux Data Processing System at ChinaFLUX
ChinaFLUX CO2通量数据处理系统与应用

The standardized processing of observed CO2 flux data and issue of high grade data product are the precondition and foundation of researches at CO2 Flux and its related field.However,there are a system of problems when we process these observed flux data,such as tedious processing,unified methods and lag of processing.In order to solve these problems,we choose MATLAB as development toolkit.Through making a use of its powerful mathematical computation functions and visible GUI technology,and through making an integration of current flux data processing methods,we developed the processing system of observed flux data at ChinaFLUX with independent intellectual property rights.The processing object is to observe CO2 flux data with half-hour interval.The main processing steps included turbulent flux computation,quality control/quality assurance of observed data,gap filling of missing data,separation and computation of carbon flux exchange at different time scales and so on.On the basis of current researches at ChinaFLUX,we improved the algorithms of abnormal data rejection,u* threshold determination and nonlinear gap-filling method,which we considered to be optimal.The outputs of NEE,GEE and Re at Qianyanzhou Flux Tower at ChinaFlux are-352.19 gC m-2 y-1,1 284.88 gC m-2 y-1 and-1 637.07 gC m-2 y-1,which are similar to other research results.This system,with high automaticity and visualization,can provide a valid platform for processing observed CO2 flux data.