华南锋面和季风降水环流特征及加热结构对比分析

选取华南2017年5月15日两段不同系统影响的典型个例降水，基于ERA Interim分析资料和地面、雷达等观测资料，从两类降水的大尺度环境及中尺度特征方面探讨了两类降水系统的差异，并利用模式潜热廓线订正方案对两类降水个例的潜热进行反演。结果表明，季风降水主要受偏南风影响，边界层内强辐合、高温高湿，中高层（600~150 hPa）较强辐散，而锋面降水受低层锋面系统影响，对流层低层强辐合，800~300 hPa较强辐散，水汽输送深厚，斜压性结构明显，且垂直运动剧烈。除两者的辐合辐散中心、正涡度的中心以及水汽通量辐合中心和垂直运动大值中心所在的层次明显不同外，其强度也差别较明显，就垂直运动而言，锋面降水的最大值达-1.2 hPa/s，远远大于季风降水（-0.2 Pa/s）。两者的中尺度特征和加热结构也存在显著差异，季风降水中尺度雨团沿海岸线自西向东移动发展，潜热加热中心为单峰值，位于5~6 km；锋面降水中尺度雨团在一条西南-东北走向的雨带上不断向东南方向合并发展，潜热加热中心有两个，分别位于1~2 km和6~7 km。 

COMPARATIVE ANALYSIS OF FRONTAL AND MONSOONAL PRECIPITATION CIRCULATION CHARACTERISTICS AND HEATING STRUCTURE

Based on the analysis data of ERA Interim and observation data such as ground data, radar reflectivity data and satellite data, we choose the two typical precipitation cases affected by different synoptic systems to investigate the differences of two precipitation systems in large-scale environmental characteristics and meso-scale activity features. The latent heating rates of the two precipitations are retrieved with the use of the revised scheme of latent heating profile in the model. The results show that the monsoonal precipitation is affected by southerly wind, with strong convergence, high temperature and moisture in the boundary layers and strong divergence in the mid-high levels (600~150 hPa) of troposphere. The frontal precipitation is influenced by the frontal systems, with strong convergence in the low levels of troposphere, strong divergence in low-mid levels (800~300 hPa) of troposphere, and deep moisture transport. In addition, the baroclinic structure is very obvious and the vertical motion is intense in the frontal precipitation. Between the two precipitations, except for the differences of located level of centers from the convergence and divergence as well as from the vertical motion, the intensity of each center is quite different. As for vertical motion, the maximal value in the frontal precipitation is -1.2 hPa/s, which is greater than that that in the monsoonal precipitation (-0.2 hPa/s). There also exist significant differences of meso-scale features and latent heating structure in the two types of precipitation. For monsoonal precipitation, meso-scale rain clusters move westward to eastward along the coastline and latent heating center is a single peak, located at 5~6 km height. However, for frontal precipitation, meso-scale rain clusters are continuously merged to the southeast in a southwest-northeastern rainbelt. There are two latent heating centers, located at 1~2 km and 6~7 km height, respectively.