• 关键词：中尺度扩散  高阶矩  湍流闭合  随机游动  热力内边界层  熏烟扩散

• 基金项目：

• 于洪彬
• 南京大学大气科学系, 南京 210008

• 蒋维楣
• 南京大学大气科学系, 南京 210008

• 摘要：建立了一个沿岸熏烟扩散的中尺度模拟系统, 它由一个二维二阶矩闭合的PBL模式和一个随机游动扩散模式组成。初步的模拟和一些数值试验结果表明, 随机游动扩散模式与现行的基于高斯扩散公式的熏烟扩散模式比较, 其物理模型更为合理；采用二阶矩湍流闭合方案的P8L模式能模拟得到合理的热力内边界层（TIBL）结构特征；将二阶矩湍流闭合PBL模式模拟所得气象场作为随机游动扩散模式的气象输入, 可以较好地预测沿岸地区日间持续发生的熏烟扩散过程。这一模拟系统能从本质上揭示TIBL的湍流结构, 从而可模拟得到更加接近实际的扩散

• Abstract：A mesoscale simulation system for fumigation dispersion over shoreline area,composed of a two-dimensional second order turbulence closure PBL model and a random walk dispersion model,was established.The results of preliminary simulation and Some numerical tests showed that,the physical model for random walk dispersion model is more valid than those of present fumigation dispersion model based on Gaussian diffusion formulation. The second-order turbulence closure PBL model could obtain sound characteristics of the thermal internal boundary layer(TIBL) structure,Using mean and turbulent fields obtained from second-order turbulence closure PBL model as meteorology inputs for stochastic dispersion model,one could well predict the procedure of fumigation dispersion in the daytime over shoreline area. The modeling system could reflect turbulence distribution of TIBL,so that more information on the realistic dispersion features can be obtained.

• Key words：mesoscale dispersion  higher-order moments turbulence clo-sure  random walk  thermal internal boundary layer  fumigation dispersion

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