对流边界层中地面源的铅直扩散模拟

对流边界层(CBL)中高架源浓度轴线下倾而地面源浓度轴线上升。本文分析了形成这种相反的几何图象的机理，从而认为:只要能够恰当模拟CBL中铅直湍流结构的特征，一个粒子随机扩散模式应既能模拟高架源的扩散，也能模拟地面源的扩散。因此，用作者早先模拟高架源的模式模拟了地面源的铅直扩散，同样获得较好的结果，进一步证实了模式的有效性。本文还应用Thomson准则检验了模式，讨论了它在理论上的合理性和适用范围。

The Simulation of Vertical Diffusion for the Surface Release in the Convective Boundary Layer

It was found that the mode of maximum concentration descended for the elevated releases, bot lifted for the near-surface releases in the convective boundary layer (CBL). The mechanism which causes this oposite geometric figures is analysed. It is believed that either the diffusion of elevated releases or that of near surface releases can be simulated by a same random diffusion model, provided the characteristics of the vertical turbulence in the CBL can be simulated properly. Therefore, the model used to simulate the diffusion of elevated releases by authors before is used to the simulation of near-surface releases, and the satisfactory result is obtained as well. This confirms the effectiveness of the model further. The model is examined by the Thomson's criteria. The theoretical reasonableness and the application limits of the model is discussed.