丽江暴雨的多普勒雷达回波特征研究

Study on Doppler Radar Echo Characteristics of Lijiang Rainstorm

摘要: 本文精选了6年来出现在丽江市4个气候站的暴雨个例，利用多普勒雷达资料的强度场和径向速度资料对暴雨个例进行了详细的分析, 结果表明：丽江市的暴雨主要出现在汛期(5到10月)。丽江暴雨雷达回波在强度场上前期多以积层混合降水回波为主，后期减弱为层状云降水回波。大多数宁蒗站和华坪站暴雨中，回波强度值都在45 dBz以下，这在以后的暴雨临近预报中需要特别注意。在速度场上的主要特征是：零径向速度线走向呈现出直线型、“S”型、反“S”型、折角等特点，其中零径向速度线有折角的出现次数较多，同时还具有逆风区、辐合线、速度模糊、低空急流等特征，但以逆风区、辐合线为主。

Abstract: In this paper, the rainstorm cases which occurred in 4 climate stations in Lijiang City in the past 6 years are selected. The intensity field and radial velocity data of Doppler radar data are used to analyze the rainstorm cases in detail. The results show that the rainstorm mainly occurs in the flood season (May to October) in Lijiang City. The radar echo of Lijiang rainstorm in the intensity field was mainly composed of stratified mixed precipitation echo in the early stage and weakened to stratified cloud precipitation echo in the late stage. The echo intensity values of most Ninglang stations and Huaping stations are below 45 dBz in the rainstorm, which requires special attention in future rainstorm forecast. The main characteristics of the zero radial velocity line in the velocity field are as follows: the trend of the zero radial velocity line presents the characteristics of straight line, “S” shape, reverse “S” shape, and broken Angle, among which the zero radial velocity line has broken Angle more times, and also has the characteristics of upwind zone, convergence line, velocity blur, low-level jet, etc., but the upwind zone and convergence line are the main ones.