摘要
对 94 0 6 (Tim)台风登陆北上并与西风带槽相互作用 ,引发我国东部大暴雨的过程进行了诊断研究 ,并与北美的个例进行了对比。发现Tim与北美的Hazel、Agnes、Camile飓风虽同属于低纬度系统北移被中纬度西风槽所“捕获” ,但上述北美飓风均转变为锋面气旋 ,发展过程基本上与挪威学派经典的A类气旋及Petterssen定义的B类气旋相似 ,而Tim不属于上述两类情况。对涡度方程的诊断表明 ,此过程在低层除平流项外 ,散度项也比垂直输送项和扭转项大一个量级。而高空散度项、垂直输送项和扭转项同量级 ,此时扭转项的贡献也不可忽视。对水汽来源的诊断表明 ,对华北和东北的降水而言 ,尽管孟加拉湾有丰沛的水汽输送至东亚 ,但是南海和西太平洋的水汽输送仍有重要贡献。
In mid July 1994, a typhoon (Tim) landed, moved northward, then, interacted with the trough in middle latitudes and finally, produced heavy rainfalls in the eastern China In this paper, a diagnostic study has been conducted and comparisons between this case and North American cases have been made It is found that both Tim and North American cases are of lower latitude systems captured by the baroclinic zone when they move to the mid latitudes The North American cases can be transferred into the extratropical cyclones; they can be thought as a near-classic examples of Norwegian school (type A) and Petterssen school (type B) But Tim is not similar to the above mentioned two types Computations of the various terms of vorticity equation show that in this case, both the horizontal advection and convergence effects are one order larger than the vertical advection and twisting terms in the lower troposphere, and convergence term should be considered However, the twisting term has about a same order as the horizontal advection and divergence terms in the upper troposphere Different from the North American cases, the twisting term cannot be ignored The analysis of the moisture source show that the Indian monsoon is an important moisture supply area, although the South China Sea and the West Pacific are still of important moisture sources
出处
《大气科学》
CSCD
北大核心
2000年第2期223-237,共15页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金项目!4 98750 1 1
中国科学院重点基金项目!KZ952 -J1 -4 0 3
关键词
台风
暴雨
中尺度对流系统
typhoon
heavy rain
mesoscale convective system
