2016年14号台风“莫兰蒂”特征分析

Analysis on the Characteristics of the Fourteenth Typhoon “Morandi” in 2016

为研究2016年14号台风"莫兰蒂"发生期间的降水及结构等特征,选用2016年9月5-20日的中国测站资料、台风资料及NCEP提供的1°×1°的再分析资料,对台风登陆前后的环流形势、降水时空分布及水汽通量散度特征、强降水相关的动力场进行分析。结果表明:"莫兰蒂"自生成以来路径较稳定、影响范围广、强度发展快、降水时段集中且区域性强。台风登陆前后的降水在大尺度环流和动力场上有很好的表现。源源不断的水汽从沿海一带的海峡及南海北部和台湾以东洋面向北输送,低层存在较大的水汽通量辐合。台风在急剧增强的过程当中,其中心周围低层维持辐合,高层则维持辐散,有利于对流发展。暴雨区的降水强度与垂直上升运动速度的大值区存在良好的对应关系。台风登陆时其中心位置垂直螺旋度为负值,意味着在气旋区存在上升运动以及向上输送的正垂直涡度。

For researching the precipitation and structure of the typhoon "Moranti", China Station data from September 5, 2016 to September 20, 2016, typhoon data and 1 °× 1 ° reanalysis data provided by NCEP are used to analyze the circulation feature and precipitation of the typhoon "Morandi" and the dynamic quantity of heavy rainfall. The results showed that,"Morandi" has a stable path since its formation, a wide range of influence, rapid development of intensity, concentrated precipitation period and strong regionality. The precipitation before and after typhoon landing has a good performance in large-scale circulation and dynamic field. A steady stream of water vapor is transported northward from the straits along the coast and the northern South China Sea. There is a large convergence of water vapor flux in the lower layer. During the process of rapid intensification, the low level around the center maintains convergence while the high level maintains divergence, which is conducive to the development of convection. There is a good correspondence between the precipitation intensity in the rainstorm area and the large value area of the vertical upward velocity. When typhoon landed, the vertical helicity of its center position was negative, which meant that there was upward movement and upward transport of positive vertical vorticity in the cyclone area.