一个大气边界层非线性三维数值模式及其在太湖流域的应用

本模式用以K半经验理论为基础的闭合方程组求解,引进了地形作用、动量、热量和水汽的侧向扩散和垂直湍流交换以及凝结加热等物理过程,其中湍流交换系数K是地表粗糙度、几何高度、大气稳定度及风速切变等因子的函数。本模式还考虑了山地、平原和水面在地形高度、地表粗糙度、辐射、蒸发及热交换等方面的差异,在下垫面上建立热平衡方程与边界层内控制方程耦合。将模式应用于太湖流域,计算得到的该流域边界层内温、压、湿、风的分布特征与实际情况相似,模式具有一定的实用性。

A NONLINEAR 3-D MODEL OF THE ATMOSPHERIC BOUNDARY LAYER IN TAIHU LAKE WATERSHED

A nonlinear 3-D model is developed to study the influence of topography and water-land distribution on the local boundary layer, including the effects of orographic fluctuation and phase change of water. The horizontal and vertical eddy viscosity and diffusion of heat and vapor are represented by parameters based on K theory, in which the coefficients of turbulent exchange are regarded as a function of surface roughness, altitude, atmospheric stability and stress tensor. The surface features and physical processes on the surface determine the local environment of the global climate background. In this model, underlying surface differences in hilly, plain and lake areas in orographic, altitude, surface roughness, radiation, evaporation and heat flux are considered. The equation of heat balance on the surface coupled with the governing equations in boundary layer is also taken into account.