A Model Intercomparison for Homogeneous Flow Over Large-Scale Orography

[摘要] We compare solutions of the equations for three-dimensional inviscid homogeneous flow to those of the shallow water equations and the nonlinear and linear barotropic vorticity equation for flow over and around obstacles which resemble the Tibetan Plateau.The homogeneous flow splits in front of the obstacle in two branches even at levels well above the plateau height, the northern branch being slightly more intense. The flow above the plateau is relatively weak as compared to the flow around it. It is found that both the nonlinear vorticity equation and the shallow water equations are qualitatively correct in predicting this splitting but tend to produce too strong flow above the plateau. However, the results obtained from the linear vorticity equation are not even qualitatively correct. The reasons for this failure are discussed.

[学科分类] 大气科学