梅雨锋江淮气旋发展机制及其与暴雨的关系  

Analysis about Development Mechanism of Jianghuai Cyclone in Meiyu Front and Its Relationship with Rainstorm

作　　者：徐娟[1] 周春雨[1] 高天赤 

机构地区：[1]杭州市气象局,杭州310051

出　　处：《科技通报》2013年第5期24-29,86,共7页Bulletin of Science and Technology

摘　　要：用NCEP/NCAR 1°×1°再分析资料、卫星云图和地面降水资料,对2011年6月14～15日发生在长江中下游的一次梅雨锋暴雨中江淮气旋的发展机制、结构特征及其与暴雨的关系进行分析。结果表明:此次江淮气旋在陆地上持续36 h之久,分为新生少动和发展东移两个阶段。扰动小槽、高低空急流为气旋加强提供动力机制。冷空气在气旋东移中逐渐减弱,中低层正涡度平流出现在气旋过境前6 h。气旋上空边界层为浅薄的东北风,中高层为西南风。暴雨主要出现在暖湿气流沿气旋南侧倾斜上升区,上升运动可达对流层顶。气旋前部暖式切变引发的暴雨大多分布在距气旋中心100～300 km范围内,而后部冷式切变引发的暴雨分布范围要广的多。In this paper,using NCEP / NCAR 1 °x 1 °reanalysis data,satellite data and ground precipitation data,the cyclone development mechanism,structure characteristics and its relationship with rainstorm,which appears on a Meiyu front in the middle and lower Yangtze River during June 14-15 2011,are analyzed.The results show that the cyclone remains 36 hours on land.There are two stages during cyclone development,in the first stage,the Jianghuai cyclone is newborn and motionless;and in the second stage,the cyclone develops and moves eastward.The disturbance trough,the high and low jet streams provide the dynamic mechanism giving birth to the cyclone and strengthening it.Cold air abates when the cyclone moves eastward,positive vorticity advection at middle and low level appears 6 h before cyclone passing through.There are shallow northeast wind in the cyclone boundary layer and southwest wind in the middle-high level over the cyclone.Heavy rain occurs mainly in warm and wet airflow climbing up along the oblique front area to the south of cyclone,which can rise to the tropopause.The heavy rain caused by the warm shear in the front is mostly located in the 100～300km range to the centre of the cyclone,while the rainstorm caused by the cold shear is scattered in more wide region.

关 键 词：梅雨 暴雨 江淮气旋 发展机制 

分 类 号：P458[天文地球—大气科学及气象学]