一次台风移出后MCC发展成因分析  

ANALYSIS ON THE CAUSE OF MESOSCALE CONVECTIVE COMPLEX DEVELOPMENT AFTER A TYPHOON MOVED OUT

作　　者：刘晓波 孙军 许映龙 陈双 LIU Xiaobo;SUN Jun;XU Yinglong;CHEN Shuang(National Meteorological Center,Beijing 100081 China)

机构地区：[1]国家气象中心,北京100081

出　　处：《热带气象学报》2023年第2期205-217,共13页Journal of Tropical Meteorology

基　　金：气象能力提升联合研究专项(22NLTSZ002);国家自然科学基金(U2142205);国家气象中心预报员专项(Y202108)共同资助。

摘　　要：应用FY-4A卫星云顶亮温(TBB)、自动站雨量资料和ERA5(0.25°×0.25°)再分析资料,对2020年第4号台风“黑格比”移出后在杭州湾生成MCC发展成因进行了分析。结果表明:(1)台风南侧的切变线辐合抬升作用以及南亚高压东部反气旋环流辐散抽吸作用,有利于中低空大气上升运动的增强,为MCC的发展增强提供良好的动力抬升条件;(2)低层台风北上后,其移动方向左后侧的冷空气南下,并与长三角地区的西南低空暖湿气流强烈交汇,斜压锋生增强,形成较强的上升运动;(3)受大陆高压东移影响,对流层中高层干冷空气东移,叠加在对流层中低空暖湿急流之上,形成了有利于MCC发生发展的大气位势不稳定层结;(4)切变线南端的西南低空急流不仅加强了低层大气的辐合和上升运动,更重要的是为MCC的发生发展提供丰富的水汽输送和汇聚;(5)水汽凝结潜热释放在MCC发展中起重要作用。水汽释放潜热加热大气,使上升运动增强,低层辐合进一步增强。低层水汽汇聚并不断向高空输送,补偿了高空凝结的水汽,潜热的不断释放,有利于MCC发展和维持。总之,台风中心移出后,台风南侧的切变线及其南侧的西南暖湿气流稳定地维持在MCC上空,为MCC的发展提供良好的动力和热力条件。The FY-4A satellite brightness temperature(TBB),automatic weather stations rainfall data and ERA5(0.25°×0.25°)reanalysis were used to analyze the causes of the development of a mesoscale convective complex(MCC)in Hangzhou Bay after Typhoon Hagupit(coded 2004)moved out in 2020.The results are shown as follows.(1)The convergent and uplifting effect of a shear line on the south side of the typhoon as well as the divergent and pumping effect of anticyclonic circulation in the east of the South Asian High were conducive to the enhancement of the vertical ascending motion of the atmosphere in the middle and low levels,and provided good dynamic conditions for the development and enhancement of the MCC.(2)After the typhoon moved northward,it guided the cold air on the rear left side of its moving direction to go southward,and strongly intersected with the warm and humid air of a southwesterly in the low-level in the Yangtze River Delta region,which intensified the baroclinicfrontogenesis and formed a strong upward movement.(3)With the eastward movement of a continental high,the dry and cold air in the mid-and upper-level also moved eastward toward a warm and humid jet in the low-level,forming an unstable atmospheric potential stratification that was favorable for the occurrence and development of the MCC.(4)The southwest low-level jet at the southern end of the shear line not only strengthened the convergence and upward movement of the low-level atmosphere,but also provided abundant water vapor and energy transport for the MCC development.(5)Latent heat release played an important role in the MCC's development.The latent heat heated the atmosphere,which enhanced the ascending motion,and the convergence of the low-level.The low-level water vapor converged and was continuously transported to the high-level,which compensated the water vapor condensed in the upper air,and the latent heat was continuously released,which was conducive to the development and maintenance of the MCC.In conclusion,after the typhoon center moved

关 键 词：暴雨 台风 中尺度对流复合体(MCC) TBB 潜热释放 

分 类 号：P445[天文地球—大气科学及气象学]