摘要
针对受0716号台风罗莎影响产生的上海大暴雨和大风过程的特点及成因,利用上海地区地面自动气象站和高空加密观测资料,结合天气图、NCEP再分析资料、卫星和雷达资料进行分析。结果表明:台风罗莎对上海造成的降水分两阶段:第一阶段是台风外围云系发展成中小尺度的云团产生的强降水,第二阶段是冷空气与台风结合的稳定降水。冷空气侵入时间与上海降水开始时间非常吻合。台风北侧副热带高压带减弱,对流层中高层转南风,加之台风本身蕴涵的丰富水汽,为台风外围强降水的发展和维持提供了深厚的热力和水汽供应;干冷空气南下和台风外围暖湿气流北上使辐合加强,为激发台风外围中尺度对流云团提供了动力抬升机制。由于冷空气浅薄,台风中高层的环流结构没有被冷空气破坏,使得底层的冷空气较长时间维持在上海附近,是上海长时间发生强降水而导致暴雨的主要原因。
By use of AWS and other upper data, NCEP reanalysis, satellite and radar data, the reasons of heavy rain and strong wind in Shanghai caused by Typhoon Krosa （0716） during Oct. 7 - 8, 2007 are analyzed. Results show that the precipitation in Shanghai can be divided into two phases： the first is strong precipitation caused by the meso-scale cloud evolved from the periphery of typhoon; the second is the steady precipitation caused by combination of cold air and typhoon. The time of cold air invasion coincides closely with that of precipitation in Shanghai. The invasion of cold air is the main reason of heavy rain in Shanghai. In addition to the rich water vapor of typhoon itself, the subtropical high weakens on the northern side of typhoon and wind direction turns to southerly on the mid-high level of troposphere, the heat and vapor are provided for the development and maintenance of strong precipitation on the periphery of typhoon. Southwards cold and dry air together with warm and waterish current on the periphery of typhoon lead to stronger convergence, which provides the dynamic elevation mechanism for meso-scale convec- tive cloud on the periphery of typhoon. Due to the flimsy cold air, the warm core of typhoon on the high levels is not destroyed. It leads to the cold air hovering near Shanghai, which slows down the moving velocity of typhoon and helps to durative heavy rain in Shanghai.
出处
《气象》
CSCD
北大核心
2008年第12期72-78,I0004,共8页
Meteorological Monthly
基金
上海市科委重大项目分项"洋山港海域大风大雾实时监测和预报技术研究及应用示范"
课题号:06DZ2011
关键词
台风罗莎
暴雨
大风
typhoon Krosa heavy rain strong wind
