摘要
大孔径闪烁仪可以获取公里级尺度的显热/潜热通量,其观测数据在农林业、水文、气象等领域的研究中具有越来越重要的作用。以海河流域2008年密云站和馆陶站大孔径闪烁仪的观测数据为例,讨论了数据筛选与处理方法,以及大气不稳定状态下不同处理方法对显热通量造成的影响。结果表明:空气折射指数结构参数应结合电压信号的方差进行计算、采用逐日的日平均波文比系数进行湿度订正、结合空间权重函数计算有效高度、选取Andreas(1988)稳定度函数计算显热通量等是可信的。通过对不同插补方法的比较可知,采用非线性回归方法和以零值替代的方法对不稳定状态和稳定状态下30 min缺失的显热通量进行插补,采用动态线性回归方法对日显热通量的缺失进行插补是可行的。为了解决由于冬天净辐射和显热通量较小,造成能量平衡方程余项法计算的蒸散量产生较大误差的问题,可采用根据大孔径闪烁仪与涡动相关仪观测的日蒸散量建立的关系式进行估算。基于上述方法的研究,形成了一套较为完整的大孔径闪烁仪观测数据的处理流程,保证了在不同下垫面、不同的天气状况条件下都能获取质量可靠、数据连续的大孔径闪烁仪观测的显热/潜热通量。
Sensible/latent heat fluxes can be obtained by Large Aperture Scintillometer（LAS） over several kilometers,which play an significant role in the analysis of and application to agricultural and forestry,hydrology and meteorology research.Take LAS observations in Miyun and Guantao stations over Hai River Basin in 2008 as an example.The way of data screening and quality control under unstable conditions as well as the effect of different calculation method on sensible heat flux have been discussed.The results showed： the structure parameter of the refractive index（C2n） should be calculated with the variance of the voltage of structure parameter of the refractive index;Humidity correction can be done with daily Bowen ratio;The effective height of LAS can be calculated with spatial averaged function;The Andreas（1988） function is used to get reliable sensible heat flux.Meanwhile,the nonlinear regression method and dynamic linear regression method have been used to fill the 30min and daily missing data while the 30 min missing data under stable conditions can be set to zero.The correlation relationship between daily ET measured by LAS and EC has been constructed to estimate daily ET when daily Rn50 W/m2.Based on the above analysis,a set of LAS data processing scheme has been set up,which ensures continuous and high quality sensible/latent data can be obtained over various surfaces and weather conditions.
出处
《地球科学进展》
CAS
CSCD
北大核心
2010年第11期1148-1165,共18页
Advances in Earth Science
基金
公益性行业(气象)科研专项“大尺度水热通量观测系统的研制与应用研究”(编号:GYHY200706046)
国家自然科学基金项目“地表水热通量的时空尺度扩展研究”(编号:40971194)和“基于遥感和数据同化方法的海河流域水文通量预测研究-SP2:不同尺度蒸散量和土壤水分的观测研究”(编号:30911130504)资助
关键词
大孔径闪烁仪
数据筛选与质量控制
不稳定状态
插补
Large Aperture Scintillometer
Data screen and quality control
Unstable condition
Gap filling methods
