Abstract: Diffusion process of tracer experiments on complex seashore of Sanmen in Zhejiang Province of China is simulated by a combined modeling system. This system is composed of the diagnostic wind model Calmet, which provides a high-resolution wind field, and the Lagrangian random-walk dispersion model RPPM which calculates surface concentration distribution for comparison with the field measurement. In each tracer experiment, tracer concentration is measured at sample stations which spread over several arcs so as to capture the main body of the plume. Comparison between surface concentrations generated by the two methods reveals that the modeling system considerably well simulates the trajectory of the plume and distribution of surface concentration.

Key words: atmospheric diffusion, random-walk dispersion model, tracer experiment, topographic perturbation

摘要： 使用一套耦合的模式系统模拟了浙江三门海岸复杂地形示踪试验的扩散过程。模式由风场诊断模式Calmet和拉格朗日随机游走扩散模式RPPM组成，Calmet提供高分辨率风场，RPPM计算地面浓度用以和实际观测值比较。在每次实验中，示踪物浓度在取样点处测得，所有的取样点分布在几条弧线上以便捕捉到烟流主体。由两种方法得到的地面浓度比较表明，这套模式系统较好地模拟了烟流的轨迹和地表浓度分布。

关键词: 大气扩散, 随机游走扩散模式, 示踪实验, 地形扰动