湍流的频散效应对行星边界层大气平衡运动的影响

EFFECT OF TURBULENT DISPERSION ON BALANCE MOTION OF PBL ATMOSPHERE

中文摘要:

      本文应用包含湍流粘性和湍流频散效应的新的Reynolds平均运动方程求解了行星边界层中大气的平衡运动,着重分析了湍流频散效应对平衡运动的影响。分析指出:(1)考虑了湍流频散效应后,在γ>0时,Ekman层风速随高度的变化减缓,而Ekman层厚度增大,新的Ekman螺线更加附会于实际;(2)考虑了湍流频散效应后,近地面层中性层结下的风速随高度变化仍呈对数定律,只是Karman常数k变为k₁=k√1-k/2因而风速随高度变化也有所增加。

英文摘要:

      New Reynolds mean momentum equations including both turbulent viscosity and dispersion are used to analyze the balance motion of the planetary boundary layer.It is pointed out that the turbulent dispersion with γ>0 will;increase the depth of Ekman layer and reduce the wind velocity in the Ekman layer and obtain a more satisfatory Ekman spiral fit to observed wind hodograph.The wind profile of surface layer including turbulent,dispersion is still logrithmatic,but the von Karman's constant k is replaced by k₁=k√1-k/2,so the wind speed increase a little rapider with height.