2012年7月中旬一次安徽梅雨锋暴雨过程的干侵入分析

利用NCEP/NCAR 1°×1°再分析资料,着重对2012年7月13—14日发生在安徽中南部的一次梅雨锋暴雨过程中干侵入的特征及作用机制进行了诊断分析。结果表明,此次强降水是在高空低槽和低空冷式切变线共同作用下产生的。暴雨过程中,从对流层高层到低层有明显的干侵入。在整个对流层上均存在干侵入,但是对流层中高层较强,低层较弱,干侵入主要来自对流层中高层。高低空急流耦合产生次级环流,其正环流圈下沉支为干冷空气侵入提供了动力条件。低湿、高位涡的干冷空气具有沿假相当位温密集带（即锋面）下传的特征。

ANALYSIS OF DRY INTRUSION DURING AN ANHUI WEIYU FRONT RAINSTROM PROCESS

By using the NCEP/NCAR reanalysis data, the dry intrusion of a Meiyu front rainstorm occurred in the south central of Anhui province during 13-14 July 2012 was analyzed. The results show that the occurrence of heavy rainfall was caused by the interaction of the upper trough and low-level wind shear line. Although the dry intrusion occurred at all levels of the troposphere, its effect on the middle and upper troposphere was stronger than that on the lower troposphere. The dry intrusion mainly came from the upper troposphere and played an important role in the development of the formation of Meiyu-front. The dry air with high potential vorticity presented the downward characteristics passing along equivalent potential temperature intensive belt.