深圳地区海岸复杂地形下大气输送与扩散模拟

NUMERICAL SIMULATION OF ATMOSPHEERIC TRANSPORT AND DIFFUSION OVER COSTAL COMPLEX TERRAIN IN SHENZHEN REGIONS

利用边界层预报模式提供的非定常的风场和湍流场，采用实用的考虑风切变的烟团模式模拟了海岸复杂地形下（深圳地区）高架点源（电厂）排放ＳＯ２的地面浓度变化特征．联接模式细致地考虑了地面反射、混合层穿透和反射．结果反映了风场湍流场的非均匀非定常对浓度分布有较大影响．在海陆风转换期内，地面浓度分布型式较乱，只有在海风盛行时，浓度分布与简单的高斯模型结果接近．浓度变化呈现明显的周期性，最大浓度出现在陆风向海风转换期内，日均最大浓度分布在陆上．这些特征在常用的高斯模式中是无法反映的．

The puff trajectory model was used to simulate the transport and dispersion of SO 2 released from elevated point source.Time dependent three dimensional distributions of mean and turbulence variables needed in the puff diffusion model were provided by nonhydrostatic PBL model with energy closure scheme.The reflection on both of the ground and the top of mixlayer,penetration on the top of mix layer were considered in detail.The results indicated that time variation and nonuniformity of airflow and turbulence obviously affected the concentration distributions.Especially during the period of sea land breeze transition,the distribution pattern of ground level concentration is irregular.It is close to that obtained from Gauss model only when sea breeze fully developed.In a day,the periodic variation of ground level concentration was found,its maximum value appeared when land breeze turn to sea breeze.The daily mean of concentration was found on land.The analysis revealed that the above mentioned characteristics of concentration distribution over coastal complex terrain could not be obtained from simple Gauss model.