一次广东省大雾过程的数值模拟分析  

NUMERICAL STUDY OF A HEAVY FOG EVENT IN GUANGDONG PROVINCE

作　　者：樊琦[1,2] 王东海[2] 黄聪敏[1] 范绍佳[1] 王安宇[1] 冯瑞权[3] 

机构地区：[1]中山大学季风与环境研究中心/大气科学系,广东广州510275 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]澳门地球物理暨气象局

出　　处：《热带气象学报》2009年第5期589-595,共7页Journal of Tropical Meteorology

基　　金：中国气象科学研究院灾害天气国家重点实验室开放基金;广东省博士启动基金项目"华南南岭山地雾的数值模拟和数值预报研究"共同资助

摘　　要：利用美国国家大气研究中心(NCAR)和宾夕法尼亚州立大学联合研制的第5代中尺度气象模式系统MM5,对广东省地区春季出现的一次大雾过程进行了数值模拟研究。模式模拟结果与实际温湿探空的对比表明,模式很好地模拟了大雾过程的流场变化特征及表征大雾的液态水含量分布。对这次大雾生消过程起决定性作用的是925hPa风场的变化。当925hPa转为偏南风控制时,暖湿的海洋性空气流经较冷的下垫面从而形成大范围的平流雾;而当925hPa转为干冷的偏北风控制时,原本形成的大雾很快就消散了。同时模式也很好地模拟了伴随此次平流雾出现的逆温过程。逆温层高度约在900hPa附近,具有相当的厚度,这对于大雾的形成和维持有一定作用。另外,利用模式模拟的液态水含量值估算的能见度水平分布情况与实况的观测结果也较为一致。PSU/NCAR MM5 was utilized to simulate a heavy fog event occurred in spring in Guangdong province. The simulation results were compared with the actual soundings. It showed that the distributions of the stream fields and the liquid water contents of the fog were simulated very well. The formation and dissipation of the fog were dominated by the change of wind in 925 hPa. When it was controlled by south wind, the warm and moist air from South China Sea moved through the comparative cold land surface, the air reached saturated and the fog formed. When the wind direction changed to by north, the fog began to decrease and dissipate. Besides, the inversion layers were also represented. The height of the inversion top was 900 hPa or so. The low level inversion was benefit to the evolution of the fog. Finally, the visibilities were calculated by the simulated liquid water contents from MM5 model. The distributions of the visibilities were consistent with the observations.

关 键 词：大雾 逆温 能见度 数值模拟 

分 类 号：P426.4[天文地球—大气科学及气象学]