近地面层热通量和气体通量光学监测新方法研究

监测地气间动量、热量和痕量气体等的交换对水文、气象和生态环境等有着重要的意义。阐述了一种利用自行研制的大口径闪烁仪(LAS)、光学温度梯度仪和基于可调谐二极管激光吸收光谱术(TDLAS)的开放光路痕量气体监测系统,实现了较大区域热通量和二氧化碳等气体通量快速监测的方法。实验结果表明,所测数据与涡动相关(EC)仪的数据比较,显热通量的相关系数为0.91,二氧化碳通量的相关系数为0.74。由此,用大口径闪烁仪监测区域热通量和基于TDLAS光学技术连续可靠监测陆地区域碳通量是完全有可能的,这种方法在大区域热通量和气体通量监测将会有很好的应用前景。

A New Optical Method for the Determination of Heat and Gas Fluxes Measurement in the Surface Layer

Routine estimates of the turbulent fluxes of momentum, heat and trace gas flux have important significance in many meteorological, hydrological and other related studies. Combining with large-aperture scintillometer (LAS), temperature-gradient measurement system and tunable diode laser absorption spectroscopy (TDLAS), sensible heat flux and carbon dioxide (CO2) flux can be derived by iterative over a long optical path. This method has realized fast detection of heat flux in large natural areas and CO2 flux. The measured fluxes of sensible heat and carbon dioxide are compared with the results measured by a eddy-covariance (EC) instrument. The results show correlation coefficient of sensible heat flux is 0.91 and that of CO2 flux is 0.74, respectively. Experimental results show that optical measurement overcomes those limitations of traditional method, so this method is an inspiring method in heat and gas flux monitoring.