Abstract: Turbulence is one of the key processes for energy exchange between land surface and atmosphere. Accurate observation on turbulent fluxes has been an important issue in the researches on urban boundary layer. Based on simultaneous observation of a large aperture scintillometer (LAS) and an eddy covariance system (EC) installed in the campus of Nanjing University of Information Science and Technology, we compared sensible heat flux measured by those two systems. The effects of underlying surface heterogeneity on the sensible heat flux were analyzed combined with the normalized vegetation index (NDVI) and the normalized building index (NDBI). The results showed that LAS and EC had a good correlation (R²=0.76), with a regression slope of 0.95. During the daytime, sensible heat flux obtained from LAS was larger than that by EC, and their difference varied between 18.8 and 39.4 W·m^-2. At night, both of them fluctuated around zero, and the difference varied between 4.8 and 28.7 W·m^-2. On the monthly scale, the difference between LAS and EC was the largest in August, followed by July and April, and the least in June. The difference attributed to the different footprints caused by the changes of wind direction. NDVI in the footprint was negatively correlated with sensible heat flux to net radiation (k=-0.34, P<0.05). NDBI in the footprint was significantly positively correlated with ratio of sensible heat flux to net radiation (k=1.15, P<0.05).

Key words:  , seed quality., oil peony, N translocation, N accumulation