特大暴雨的中-β尺度系统研究  

A Study on Meso-β Scale System During An Excessive Heavy Rain

作　　者：沈树勤[1] 曾明剑[1] 吴海英[1] 

机构地区：[1]江苏省气象台,南京210008

出　　处：《气象》2001年第12期33-37,共5页Meteorological Monthly

摘　　要：受 0 0 1 2号台风 (派比安 )外围影响 ,在 2 0 0 0年 8月 3 0日 0 8时到 3 1日 0 8时 ,江苏东北部地区出现了一次具有局域性、突发性、高强度、超历史记录的特大暴雨过程。经综合分析表明 :暴雨期间 ,在台风外围第二象限稳定的东风气流 ,并发生扰动 ,构成产生特大暴雨的中尺度东风辐合线天气系统。这条中尺度东风辐合线高频次的准东西向和高频次的准南北向分布、更替 ,与响水≥ 1 0mm雨团的高频区相一致。由地面速度平流散度 (F)分析得出 ,强雨团是与F >0的强中心趋于一致 ,也即是在辐合增强或维持最强的响水及其附近爆发。进一步分析表明Affected by the outside of the typhoon 0012 (Prapiroon),an unprecedented heavy rain process,with the character of locality,intensity and abruptness,occurred in the northeast of Jiangsu from 0800GTM 30 to 0800GTM 31 August.The analysis indicates that the stable easterly stream provided by the second quadrant of the outside of the typhoon and its disturbance constitute the mesoscale easterly stream convergence line synoptic system which results in heavy rain.The high frequency quasi east west and quasi south north distribution of the mesoscale easterly stream convergence line and their substitution is in agreement with the high frequency area where rain mass with rainfall≥10mm occurs.The analysis on the surface velocity advection divergence ( F ) shows that intense rain mass nearly accord with the severe center with F ≥0,in other words,intense rain mass explodes in Xiangshui and its vicinities where convergence strengthens or intensively maintained.The results by further analysis and statistics suggest that the changes of the surface velocity advection divergence is closely associated with the maintenance of intense local rain mass and the reinforcement of rain intensity.

关 键 词：特大暴雨 中-β尺度东风辐合线 地面速度平流散度 台风 雨团 

分 类 号：P458.121.1[天文地球—大气科学及气象学]