半地转三段k模式边界层运动

THE MOTIONS IN THE BOUNDARY LAYER UNDER THE GEOSTROPHIC MOMENTUM APPROXIMATION INCORPORATING A THREE-SECTION K DISTRIBUTION

中文摘要:

      本文在半地转近似下,取湍流粘性系数k为三段式:k₁z(z₀≤z<h₁)、k₂(h₁≤z<h₂)、k₃(h₂≤z),把行星边界层分为三层加以研究,得到了各层的风速分布和边界层顶的垂直速度的解析表达式,改进了Wu and Blumen^[1]把半地转近似引入边界层的工作。特别是使近地层的风速符合对数律,且边界层中风向与自由大气底部的风向间的最大夹角只有30°左右,这些都与实际更为一致。本文还把正压、中性大气中的解推广到斜压、层结大气中去。

英文摘要:

      By use of geostrophic momentum approximation, the analytical expressions of the wind distribution within the planetary boundary layer and the vertical velocity at the ton of the boundary layer are obtained when the distribution of eddy transfer coeffiecent k devide into three sections as follows: k₁z(z₀≤z<h₁),k₂(h₁≤z<h₂),k₃(h₂≤z).The results are in agreement with the observations. In particular, the wind profile in the suface layer (z₀≤z<h₁)coincides with the logarithmic distribution. The maximum of the angles between the wind near the surface ann the wind at the bottom of the free atmosphere only about 30°.This work improves Wu and Blumen's work^[1] which introduced the geostrophic momentum approximation to the boundary layer. The solutions in barotropic and neutral conditions have been also extended to the baroclinic and stratified atmosphere.