Analysis of the factors influencing surface sensible heat fluxes with large aperture scintillometers

Large aperture scintillometers (LAS), Bowen ratio, eddy covariance measurements, soil moisture in various depths with measuring masses and routine weather observation such as visibility, cloud, wind speed and weather phenomenon with manual work were employed to study sensible heat flux over homogeneous bare soil surface from March 20th to April 20th, 2002, at XiaoTangshan area, Beijing. The diurnal variation of sensible heat flux from LAS is analyzed in this paper, and the relation between sensible heat flux and weather conditions is discussed. Moreover, the correlation coefficient between LAS based surface sensible heat fluxes and the influencing factors such as soil surface temperature and wind speed were analyzed. The analysis will help us to improve the accurate of LAS measurements. Further, the comparisons of the scintillometer flux measurements with the measurements of Bowen ratio and eddy correlation methods were done in order to make more research on scaling-up of surface sensible heat flux from point to area