【摘要】 涡动相关仪在长时间连续观测中,观测数据会有不同程度的缺失。应用6种不同的插补方法(平均昼夜变化法MDV,非线性回归方法NLR,动态线性回归方法DLR,查表法LUT,FAO-PM方法,HANTS方法)对北京密云站2007年涡动相关仪观测蒸散量数据进行了插补。结果表明:LUT方法在不同数据缺失时均得到较好结果(均方差小于8 W/m2);MDV和NLR方法更适合于短时间数据缺失的插补;DLR和FAO-PM方法在观测数据出现连续波动时插补结果较差。由LUT、DLR、NLR、HANTS、FAO-PM方法得到的年蒸散量分别为395.8 mm、409.9 mm、393.5 mm、390.7 mm、399.4 mm,差异在2.3~19.2 mm之间变化。对比分析了LUT方法得到的年蒸散量(潜热通量)与净辐射、降水量以及LAS观测潜热通量间的变化规律,表明插补结果合理。更多还原

【Abstract】 Data missing is inevitable in long-term eddy covariance system measurement.Several gap filling methods are chosen and applied in the data sets of Miyun station in 2007.These methods include mean diurnal variation(MDV),look-up tables(LUT),nonlinear regressions(NLR),Dynamic linear regression(DLR),Harmonic analysis of time series(HANTS) as well as the method of Penman-Monteith recommend by Food and Agricultural Organization(FAO-PM).The impacts of different gap filling methods on the evapotranspiration are investigated and the results are tested.The result shows: LUT method is stable in every data missing cases(RMSD less than 8 W/m2);MDV and NLR methods are more suitable for short data missing;The gap filling results of DLR and FAO-PM methods are not good if the observed data have large change continuously.The Annual ET obtained by LUT,DLR,NLR,HANTS,FAO-PM methods are 395.8mm,409.9mm,393.5mm,390.7mm,399.4mm.The difference between annual ET filled by different methods resulted in a range of 2.3~19.2mm per year.The annual ET obtained by LUT method is compared to net radiation,precipitation and latent heat flux measured by LAS;it is shows that the results are reasonable.更多还原