摘要
利用ＰＳＵ／ＮＣＡＲ的中尺度数值模式ＭＭ５，取１９８１年６月２７日梅雨锋暴雨过程作为个例进行了数值模拟，模拟的降水结果同华东中尺度天气试验实测取得的该暴雨过程的稠密降水资料分析结果相比较，发现直到中β尺度程度上，两者的分布结构和演变过程等基本特征都是近于一致的．不论在观测分析中还是在模拟结果中，几乎与梅雨锋相平行，均出现了中α尺度（南、北）双雨带，它们均由数个中β尺度雨团组织和近乎东移所成，双雨带之间均具有些此强彼弱的演变特征．所有这些构成了梅雨锋雨区或暴雨主要的中尺度时空特征．
Heavy rainfall event of June 27,1981 in the mei yu front as a case is simulated by using PSU/NCAR mesoscale numerical model MM5.We choose a computational domain of 1920km×2130km size centered at 33°N and 120°E with a horizontal grid point spacing of 30km. However, this paper presents the mesoscale analyses in the central part, which approximately equals to the area of the Mesoscale Weather Experiment in eastern China (MWEEC) during the period of 1980 to 1983. The analysis data of the European Center for Medium Range Weather Forecasts (ECMWF) are used as initial and lateral boundary conditions necessary to drive the model to run. The model runs from 20 BJT, June 26,1981 and total run is 36 hours. The first 12 hour run is considered to excite mesoscale structures from the large scale fields by the model and the following 24 hour results are used to do analytic studies in this paper. Obviously, this is a data set with high resolution of time and space and suitable for meso β scale analytic studies. The MWEEC specially organized an intensive observation network and an experiment project. There are more than 1315 stations for precipitation data in the experiment area. Although the number of radiosonde stations increases up to twenty seven, the average distance between two stations is still more than 90km, and most of the intervals of radiosonde time are more than six hours. It is still more than 90km, and most of the intervals of radiosoned time are more than six hours. It is still not considered to be good enough to analyze meso β scale systems of heavy rain, especially for temporal and spatial characteristics on the three dimensional fields. Thus, the results from the outputs of the MM5 could remedy the defect. Comparison of the simulated precipitation with the intensive observation obtained by the mesoscale weather experiment over eastern China shows that their distributions in structure, evolution and so on are quite consistent, even on the meso β scale. Whether the observation or the simulation indicates that there exist the meso α scale double rain belts (i.e., the southern and the northern rain belts) paralleling almost the mei yu front and they result from the organization and the movement of several pieces of the meso β scale rain clusters (i.e., rainfall center for more than 10 mm/hr). Both the rain belts appear a seesaw evolutionary phenomenon in their rainfall. Those all constitute primary mesoscale temporal and spatial characteristics over heavy rainfall area in the mei yu front.
出处
《南京大学学报（自然科学版）》
CAS
CSCD
1999年第3期346-354,共9页
Journal of Nanjing University（Natural Science）
基金
教育部博士点基金
关键词
梅雨锋
暴雨雨带
中尺度系统
数值模拟
Mei yu front, Heavy rain belts, Mesoscale system, Numerical simulation
