青藏高原当雄地区湍流脉动耗散率特征研究

利用1998年第2次青藏高原气象科学实验（TIPEX）当雄地区观测站的湍流资料，分析了青藏高原中部地区湍流动能、温度脉动和湿度脉动耗散率的特征规律。结果表明，无量纲湍能耗散率φ_ε、无量纲温度脉动耗散率φ_N和无量纲湿度脉动耗散率φ_γ分别比风速梯度产生的能量、温度和湿度梯度产生的脉动约小20%，且随稳定度参数的绝对值的增加而呈增加的趋势；湍流输送和压力脉动项的影响贯穿于整个稳定度区间, 数值与z/L相联系。青藏高原中部地区湍流动能、温度脉动和湿度脉动耗散率的方程中系数与前人结果的差异，反映其对下垫面特征的依赖性。

The Characteristics of Dissipation Rates of Turbulent Variance over Damxung Area in the Tibetan Plateau

The turbulent data obtained from Damxung site during TIPEX in 1998 were used to study the characteristics of dissipation rates of turbulent kinetic energy, temperature variance and humidity variance in the middle area of Tibetan Plateau. The results indicate that the dimensionless dissipation rates of turbulent energy are 20% less than the energy produced by velocity shear, and the dimensionless temperature and humidity variances are also 20% less than the variances produced by temperature and humidity gradients. These deficits appear to increase with the increasing of the absolute stability parameter. Moreover, the effects of turbulent transportation and pressure variance, which are related with the stability parameter, persist throughout the whole stability region. The differences between these results and some previous studies show the underlying surface dependant characteristics of the dissipation rates of turbulent energy, temperature variance and humidity variance.