Abstract: Turbulence data and wind, temperature profile data areused to analyze turbulence structure within and above Changbai Mountain Forest. The normalized wind profiles within Changbai Mountain Forest is considered to be exponential: U(Z)/U (h)= exp [α₁(Z/h-1)], where α₁=2.05. The normalized momentum exchange coefficient within the canopy is proved to be exponential: K_m=(Z)/K_m (h)= exp [α₂(Z/h-1)] ,where α₂=5.2. Above the canopy, the longitudinal and lateral turbulence intersity i_u,i_v have almost the same value but the vertical turbulence intensity i_w is smaller than i_u, i_v because of the influence of the canopy. Within the canopy, i_u, i_v, i_w are similar in magnitude but larger than those above the canopy because of the big LAI and the influence of the canopy, the ground and the trunk. The spectral densities of the velocity components in the inertial subrange still can be described by the way in the flat terrain but the slopes show that they are significantly morenegative than -2/3 expecially within the canopy. In addition, the second peak of the spectrum within the canopy occurs and may becaused by wake-turbulence generation. From the data and the locally isotropic analysis, Taylor′s frozen-eddy hypothesis and locally isotropy are invalid within the canopy.

Key words: forest, profile, turbulence structure

摘要： 使用长白山森林冠层上下得到的湍流及风、温、湿梯度资料，对长白山森林冠层的湍流结构作了较为详细的分析。结果表明，冠层内的风速分布遵循指数规律U(Z)/U(h)=exp［α₁(Z/h-1)］，且α₁＝2.05；冠层内的动量交换系数满足指数律：K_m(Z)/K_m(h)=exp［α₂(Z/h-1)］，且α₂＝5.2；冠层上Z/h=1.23处，σ_w/U_*,σ_θ/θ_*与稳定度有很好的相关性；冠层上垂直方向的湍流强度i_w明显小于水平方向i_u,i_v, 冠层内，由于大的叶面面积指数(LAI)，以及树冠、地面、树干的共同作用，使得i_u, i_v, i_w十分接近且明显大于冠层上的值。冠层上下的惯性区湍流谱仍可用幂指数律描述，但斜率偏离-2/3方律，尤其在冠层内更为明显，谱曲线出现双峰现象，从资料及局地各向同性分析，冠层下的湍流并不遵从局地各向同性假设和Taylor冰冻假设。

关键词: 森林, 廓线, 湍流结构