摘要
涡动相关通量数据的处理及质量控制是保证各涡动观测台站数据质量的重要步骤。"黑河综合遥感联合试验"(Watershed Allied Telemetry Experi mental Research,WATER)从2007年底到现在连续观测积累了大量涡动相关通量观测资料。使用经过改进的Edi Re软件对盈科站、阿柔站和关滩站3个站点的原始涡动数据进行预处理和质量控制。通过异常值及野值点剔除、倾斜修正、超声虚温修正、时间滞后校正、频率响应修正和空气密度效应修正(WPL修正)等基本处理生成Level-1数据产品;再通过大气状态平稳性检验、总体湍流特征检验以及湍流通量统计特征分析等初步质量控制,生成Level-2数据产品。以盈科绿洲站2009年7月份涡动相关数据为例,着重介绍涡动相关数据处理过程中各校正方法的重要性及不同校正方法对湍流通量计算的贡献。结果表明:超声虚温修正后感热通量比修正前减少约7.7%;时间滞后校正后潜热通量和CO2通量分别增加了3.9%、2.7%;频率响应修正后感热通量、潜热通量及CO2通量分别增加了2.7%、10.5%、11.6%;WPL修正后潜热通量增加了1.7%,CO2通量减少了9.8%。最后将Campbell实时处理结果与Level-1产品及Level-2产品进行对比分析,并对黑河流域各涡动站做了总体数据精度评价,阿柔站数据质量最好,盈科站次之,关滩站较差。
Eddy covariance（EC） flux data processing and quality control is an important procedure to ensure the data quality of each observation station.A large number of flux data measured by EC system have been accumulated based on the project of ＂Watershed Allied Telemetry Experimental Research＂（WATER） since late 2007.Pre-processing and quality control were performed using improved EdiRe software developed by Edinburgh University to the original EC data at Yingke oasis station,Arou freeze-thaw observation station and Guantan forest station.The basic processing steps on the Level-1 data product including removal of outliers and spikes,tilt correction,sonic virtual temperature correction,time-lag correction,frequency response correction,and correction for density effects（WPL correction）.Level-2 data product is generated with initial quality control steps based on Level-1 data product,including atmosphere state stationarity test,overall turbulence characteristics test and turbulent flux statistical characteristics analysis.In this paper,taking EC data of Yingke oasis station in July,2008 as an example,the improvements of each correction steps during EC flux data processing and the contribution of different correction methods to the calculation of turbulent flux were analyzed in detail.The results show that：after sonic virtual temperature correction,sensible heat flux decreased about 7.7%;after time-lag correction,latent heat flux and carbon dioxide flux increased by 3.9% and 2.7% respectively;after frequency response correction,sensible heat flux,latent heat flux and carbon dioxide flux increased by 2.7%,10.5% and 11.6% respectively;after WPL correction,latent heat flux increased by 1.7%,and carbon dioxide flux decreased by 9.8%.Finally,the Level-1 product and Level-2 product were compared with the Campbell real-time processing results,and an overall data accuracy evaluation on each eddy covariance station for these three stations was obtained.It is concluded that the data quality of the Arou freeze-thaw observation station is the best,and that of the Yingke oasis station is better,and that of the Guantan forest station is poor.
出处
《遥感技术与应用》
CSCD
北大核心
2010年第6期788-796,共9页
Remote Sensing Technology and Application
基金
国家973计划项目“干旱区绿洲化、荒漠化过程及其对人类活动、气候变化的响应与调控”(2009CB421305)
国家自然科学基金项目“复杂条件下湍流通量的观测与分析研究”(40875006)
中国科学院西部行动计划(二期)项目“黑河流域遥感-地面观测同步试验与综合模拟平台建设”(KZCX2-XB2-09)
国家973计划项目“陆表生态环境要素主被动遥感协同反演理论与方法”(2007CB714400)
