自由大气非定常扰动对大气边界层的内参数的影响

THE INFLUENCES OF FREE ATMOSPHERIC NONSTATIONARY PERTURBATION ON THE INNER PARAMETERS IN THE ATMOSPHERIC BOUNDARY LAYER

本文用大气边界层运动方程的数值积分方法,研究了当自由大气(边界层顶)风作非定常的周期扰动时,对非中性层结的大气边界层的内参数u*/G(u*为摩擦速度,G为自由大气风速)和角α(地面风与自由大气风向的夹角)的影响。并将其结果与中性层结大气边界层的相应结果作了对比。最后对斜压大气情形也作了相应讨论。说明了大尺度模式中边界层的参数化的结果应考虑层结、斜压性与非定常过程的共同作用。

In the paper, the effect of the nonstationary periodic perturbation of the wind at the top of PBL on the inner parameters u*/a(u* is the friction velocity and a is the wind speed at the top of PBL) and a (the angle between the wind direction near the ground and 'the wind direction at the top of PBL) are studied by means of the numerical solution of the motion equation in the non-neutral stratrif ication of temperature PBL. The results are with the results of PBL of neutral stratification. Finally, the results of baroclinic PBL are studied. The parameterization of PBL in the large scale models which was derived in the stationary conditions should be considered as nonstationary process, stratification and baroclinic in chraeter.