冷空气对登陆台风变性发展与消亡的对比分析

Comparative Analysis on the Development and Extinction of Landfall Typhoons by Cold Air

选取对华东造成严重灾害的2007年0716号超强台风“罗莎”和2013年1323号强台风“菲特”,采用诊断分析方法,分析台风环境场、要素场及暴雨分布情况,研究两个台风个例变性期间的冷空气入侵过程,探讨冷空气与台风相互作用的演变特征及与台风暴雨生消关系。分析表明,变性台风会受到弱冷空气和海上环流系统的双重影响,形成了有利于暴雨的水汽条件和热力、动力结构,如台风“罗莎”受北部的温度浅槽和海上方头高压,台风“菲特”北部的温度浅槽、高压带和海上丹尼斯台风。弱冷空气分别从不同层次入侵两个台风,强迫台风低层暖空气抬升,垂直上升运动加剧,台风上暖下冷并向西倾,大气斜压能增加并释放,导致降水增幅。台风“罗莎”(“菲特”)台风高低层涡度、散度配置较好(不好),有(不)利于台风系统强度的维持。

The selection of east China caused serious disasters in 2007 0716 super typhoon “Rosa” and “Fitow” powerful typhoon no. 1323, 2013, by using the way of diagnosis, analysis of typhoon environment field, elements and the distribution of the heavy rain, the two typhoon case study degeneration during the process of cold air invasion of cold air and typhoon evolution characteristics of interaction and the relationship between the typhoon rainstorm born away. The analysis shows that the denatur typhoon will be influenced by the weak cold air and the sea circulation system, forming the moisture condition and the thermal and dynamic structure which is favorable to the rainstorm. For example, the temperature shallow trough and the sea square high in the north of typhoon krosa and the temperature shallow trough, the high pressure zone and the sea Dennis typhoon in the north of typhoon Fitow. Weak cold air invaded the two typhoons from different levels, forced the warm air in the lower layer of the typhoon to lift, and intensified the vertical upward movement. The typhoon warmed up and cooled down and tilted westward, and the barocline pressure in the atmosphere increased and released, leading to the increase of precipitation. Typhoon “Rosa” (“Fitow”) has good (bad) configuration of high and low layer vorticity and divergence, which is conducive to the strength of the typhoon system.