1513号台风“苏迪罗”不同阶段降水的中尺度特征分析

利用分辨率为1 °×1 °的FNL再分析资料、自动站逐小时降水资料、卫星云顶黑体亮温(TBB)资料以及雷达资料对2015年第13号台风“苏迪罗”不同阶段降水特点、引发暴雨的中尺度对流系统的环境场及其发生发展过程进行了全面分析。分析发现:台风“苏迪罗”具有强度强、在陆地上维持时间长等特点。带来的降水量大、影响范围广。其中降水主要集中在两个阶段:台风登陆过程降水及与冷空气结合引起的降水。两个阶段分别于闽北浙南一带以及江苏地区存在强降水中心，环流云系中存在着明显发展的中尺度对流云团。引发两个阶段暴雨的中尺度对流系统的环境场条件分析发现:（1）台风环流内部的中尺度对流系统的生成和发展是造成暴雨的重要原因。强降水过程发生在低层辐合高层辐散的高低空系统耦合背景下。充沛的水汽条件、地形抬升作用、冷空气入侵等条件触发了强降水。（2）闽北浙南地形抬升加强了低层气流辐合，与中高层辐散气流的相配合是引起中尺度对流活动的主要机制。台风北侧为向岸风，南侧为离岸风，水汽集中在台风主体北部辐合，非对称结构明显，这是导致第一阶段强降水中心主要位于台风主体北部的重要原因。（3）台风北上后由于台风低压环流受北侧高空槽后部冷空气影响，冷空气与南来强盛暖湿气流在苏皖地区交汇，形成强对流活动并导致第二阶段暴雨过程。 

MESOSCALE ANALYSIS ON RAINFALLS ASSOCIATED WITH TYPHOON SOUDELOR (1513) IN DIFFERENT STAGES

Based on the FNL 1°×1° reanalysis data, hourly rainfall data, TBB data and radar reflectivities, this paper analyzes the characteristics, progressions of Mesoscale Convective Systems and environmental conditions of rainfall associated with typhoon Soudelor in different stages. Study shows that the torrential rainfall produced by Soudelor with the characteristics of intensity, long duration in land, wide coverage fields and so on. Most of precipitation concentrated on two stages: typhoon landing process and in combination with cold air. Both stages had great rainfall center in their areas. There were MCSs developing obviously in circulation cloud of Soudelor.Analyzing the environment conditions of Mesoscale Convective System, the result shows that: (1)The generation and development of MCSs in circulation cloud of Soudelor are the main reason that leaded the torrential rainfall. Great precipitation had happened in background which in combination with lower convergence and higher divergence. Abundant water vapor, orographic uplift and influence of cold air provided favorable conditions to the torrential rainfall.(2)The lower convergence airflow was enhanced by the terrain in the north fujian-south zhejiang area, and caused the development of MCSs by cooperating with higher divergence airflow. Most of water vapor concentrated on the north of typhoon body. The obviously asymmetric structure of Soudelor is the main reason lead the great rainfall center of first stage located in the north of typhoon body.(3)The interaction of cold air from the upper-troposphere trough and warm air from ocean in jiangsu-anhui area is the main reason leaded the development of MCSs and the torrential rainfall in second stage.