不均匀地表产生的中尺度通量的数值试验  

A Numerical Simulation of Meso-Scale Flux over an Inhomogeneous Underlying Surface

作　　者：张治坤[1] 桑建国[1] 

机构地区：[1]北京大学地球物理系,北京100871

出　　处：《大气科学》2000年第5期694-702,共9页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金!49790020

摘　　要：采用北京大学三维的复杂地形中尺度模式，结合陆面过程模式（ＳｉＢ），模拟了草 原和沙漠并存的下垫面的边界层大气运动。利用ＳｉＢ模式计算了地表辐射。感热、潜热通 量，并且预报地表温度。中尺度模式则模拟了沙漠地区受热抬升，形成的辐合运动，垂直速 度的分布，不同高度上水平流场的变化以及中尺度动量和热量通量，把中尺度通量跟湍流通 量进行了比较，以确定这种中尺度运动在ＧＣＭ模式的参数化过程中的重要性。试验表明中 尺度通量尤其是热量通量要比湍流通量大很多。A three-dimensional mesoscale numerical model combined with SiB is used to simulate the atmospheric boundary layer over a surface of desert-grassland area. In the SiB model, we calculated the radiation, sensible heat, latent heat flux and the daily variation of temperature at the surface. From the mesoscale model, we can obtain the results such as the convergent motion in the lower boundary layer, the distribution of vertical velocity, the variation of horizontal flow field at different levels, as well as mesoscale momentum and heat fluxes. We also compared the mesoscale flux with the turbulent flux in order to confirm the importance of the mesoscale movement which is usually ingnored in the surface parameterization scheme in GCM models. The results of our numerical experiments indicate that the mesoscale flux, especially the heat flux should not be ignored over the inhomogeneous underlying surface.

关 键 词：植被 中尺度通量 不均匀地表 大气运动 数值试验 

分 类 号：P432.1[天文地球—大气科学及气象学]