不同浓度污染气溶胶对一次暴雨的影响  

Impacts of Different Concentrations of Anthropogenic Pollutants on a Rainstorm

作　　者：杨桃进 刘宇迪[1] 眭敏[1] YANG Taojin LIU Yudi and SUI Min(Institute of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101)

机构地区：[1]解放军理工大学气象海洋学院,南京211101

出　　处：《大气科学》2017年第4期882-896,共15页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目41175089~~

摘　　要：本文应用WRF-Chem模式耦合人为排放源,模拟了2011年8月13日的一次强降水过程,研究了正常(试验Norm)和两种极端情况(试验High和试验Low)下3种排放强度的人为污染气溶胶对微物理过程和降水的影响。结果表明:不同排放强度下降水开始的时间没有变化,低排放情况下降水区域未发生变化,暴雨前期试验Low的降水增强,后期减弱,降水中心强度减弱,周边降水增强,降水分散;高排放情况下降水区域明显减小,降水强度和各个量级的降水区域都减少。雨水和霰含量的变化是导致降水发生变化的原因,不同强度的污染气溶胶通过影响微物理过程影响大气的热力和动力过程,大气动力过程的变化反过来又通过微物理过程影响降水粒子的增长,从而影响地面降水。影响机理可概括为:当污染气溶胶的排放浓度增强,水汽凝结和冰晶凝华增长过程的减弱导致微物理过程的大气加热减弱,可用于发展对流的能量减少,上升运动减弱,对流强度的减弱抑制了了雨水和霰收集云水的增长,导致了可降水粒子含量的减少,降水减弱。The WRF-Chem model coupled with anthropogenic pollution sources was applied to investigate the impact of anthropogenic pollution on microphysical process and precipitation of a rainstorm occurred on 13 August 2011. Three different simulations including one normal experiment（Experiment Norm） and two extreme experiments（Experiments High and Low） according to the emission intensity of anthropogenic pollutants were conducted. The results showed that the initiation of precipitation was the same in all the three cases. In Experiment Low, the precipitation area remained unchanged while the intensity weakened at the precipitation center but enhanced in the surrounding area, and the intensity of precipitation overall enhanced（weakened） at the initial period（later period）. In Experiment High, both the precipitation area and the intensity decreased. Changes in rain water and graupel were the major reason for the change in precipitation. The anthropogenic pollutants could influence the thermodynamic processes of atmosphere through their impacts on the microphysical process, and these changed atmospheric dynamic processes in turn affected microphysics and the growth of precipitable particles. All the above processes contributed to the precipitation change in the ground. The mechanism can be summarized as follows. The atmospheric heating rate decreased due to the decrease in water vapor condensation and ice depositional growth when the emission intensity of anthropogenic pollutants enhanced, and this would cause the decrease in convective activity and suppressed the growth of rain water and graupel, resulting in the decrease in precipitable particles and precipitation reduced eventually.

关 键 词：污染气溶胶排放强度 微物理过程 降水 WRF-Chem模式 

分 类 号：P426[天文地球—大气科学及气象学]