NUMERICAL SIMULATION OF TURBULENT DIFFUSION OVER A COMPLEX TERRAIN

A set of hydrostatic atmospheric thermodynamic equations and diffusion equation are solved numerically to simulate the flow,temperature and concentration fields over the Fenhe River Valley,Shanxi Province.The results are compared with the data observed in a tracer experiment carried out in February of 1984.The concentration distributions are calculated by three approaches:ordinary grid numerical model,nested grid model and Gaussian model.The comparison shows that the nested grid model gives the best results and needs only a little more computer time.