关键词: 森林冠层动量, 热量湍涡长度尺度动量, 热量耗散率, 结构参数

Abstract: The turbulent data were measured using three-dimensional sonic anemometers/thermometers above a forest canopy, in the Changbai Mountains of northeast China. Turbulence length scales, dissipation rates and structure parameters above the forest canopy were calculated using the eddy correlation method. Results show that the turbulence characteristic length scales for momentum are negative interrelated with Z/L number; the turbulence characteristic length scales for heat is positive interrelated with Z/L number in unstable air and that is negative interrelated with Z/L number in stable air. The agreement between the momentum and heat dissipation rates calculated directly from the w spectrum(the turbulence spectral method)and indirectly from equations(15)(16)are quite good. The dimensionless turbulence structure functions C²_vz^2/3σ_w^-2 and C²_Tz^2/3σ_T^-2 are functions of Richardson number in stable and unstable air. Turbulence structure parameters C²_T has a direct linear bearing on the sensible heat flux w'T'.

Key words: forest canopy, turbulence characteristic length scales for momentum and heat, turbulence momentum and heat dissipation rates, turbulence structure parameters