林网下垫面稳定大气近地面层温、湿和风速廓线相似性及通量特征

The Similarity of Temperature, Humidity and Wind Speed Profiles and the Flux Characteristics in the Windbreak Net Underlying Surface under Stable Atmosphere

本文根据在林网下垫面测量的温、湿和风速梯度资料,分析了温、湿和风速廓线的相似性及通量特征。结果表明:在林网下垫面弱稳定大气近地面层中(0.1<Ri<0.25),温、湿和风速廓线符合Monin—Obukhov相似理论所予期的对数线性分布规律。相似函数P值在1附近,在Ri<0.25,P值变化不明显,Ri>0.25时,随Ri增大而增大。廓线参数β_u,β_?和β_w不是常数,而是稳定度参数Ri和L的函数。在Ri=0.25和L=20米附近廓线参数出现间断,两边遵循不同的变化规律。当Ri>0.25时,湍流交换减弱,感热和潜热通量的变化趋于稳定。

In this paper, the similarity of temperature, humidity and wind speed profiles obtained over the rough and inhomogeneous terrain under stabie stratified atmosphere conditions is analysed. The universal function of the Monin-Obukhov similarity and sensible heat and latent heat fluxes are also calculated. The results show that the profiles of temperature, humidity and wind speed follow the Monin-Obukhov similarity theory and the loglinear law within the range of Richardson number Ri from 0.1 to 0.25. The parameters of profile βu, βo and βw depend on Ri and L, and follow different laws within two sides of Ri=0.25 or L = 20m. When Ri>0.25, turbulent exchange is weakened, the variations of the fluxes of sensible and latent heat tend to stability.