海南岛地形对南海西行台风降水影响的数值试验  

NUMERICAL SIMULATIONS OF THE HAINAN ISLAND TOPOGRAPHIC EFFECTS ON THE RAINFALL OF WEST-GOING TYPHOONS

作　　者：杨仁勇[1,2] 闵锦忠[1] 冯文[2] 

机构地区：[1]南京信息工程大学大气科学学院,江苏南京210044 [2]海南省气象台,海南海口570203

出　　处：《热带气象学报》2013年第3期474-480,共7页Journal of Tropical Meteorology

基　　金：国家自然科学基金项目(40975068));国家科技支撑课题(2013BAK05B03)共同资助

摘　　要：使用WRF模式对2005年9月25—27日0518号强台风"达维"(Damrey)登陆海南岛过程进行数值模拟和地形敏感性试验。模拟结果表明,在海南岛中部登陆西行的台风降水分布是南多北少,南部地区降水分布是中部山区多两边少;12 km水平格距模拟的48 h降水量和每3 h降水量与实况基本相符;台风登陆时间与地点误差较小。地形敏感性试验表明,48 h降水量在有地形时海南岛上均有50 mm以上的增幅,由于五指山地形作用致使中南部地区均有100 mm以上的增幅,两个主峰区域有200～300 mm的增幅,特别是强降水中心与两座主山峰紧密相连,地形的存在对台风在海南岛上的降水增加幅度非常明显;但在海南岛东部沿海地区有50 mm的减幅作用。从低层的中小尺度流场、高度场和垂直速度的对比分析可看出:控制试验与零地形试验结果存在明显差别,五指山脉地形可增强低层扰动,有利产生中尺度对流(MCS)小涡,从而增加台风降水。Numerical simulation and terrain sensitivity experiments on Typhoon ＂Damrey＂ between September 25 and 27, 2005 were conducted using the Weather and Research Forecast （WRF） model. The results show that the rainfall caused by the west-going typhoon making landfall on the middle of the island distributes more in the south than in the north and there is more rain in the middle than the two sides in the southern area of the island. 48 h and 3 h accumulative rainfall from a 12 km experiment is successfully modeled and the landing time and location is close to the observation. A terrain sensitivity experiment shows that 48 h precipitation with terrain increases generally by more than 50 mm over Hainan Island. Increases of more than 100 mm are observed in the central and southern regions. Two peaks of heavy precipitation （200 300 ram） are found to respond to two main mountain peaks, which proves the role of terrain in general rainfall increase in typhoons. In addition, there exists a 50-mm reduction in rainfall in the eastern coast of the island. Analysis of the comparison of low-level mesoscale flow fields, the geopotential height fields and the vertical velocity shows significant differences between the control experiment and the experiment without terrain. The Wuzhishan terrain can enhance low-level disturbances, which can easily produce the vortex of mesoscale convection system （MCS）, thereby increasing the typhoon rainfall.

关 键 词：热带气旋 暴雨 数值模拟 试验 海南岛 地形 

分 类 号：P435[天文地球—大气科学及气象学]