基于多尺度小波边缘检测的对流降水和闪电分析

为准确估测对流降水，提出了多尺度小波边缘检测算法，借鉴小波变换的多尺度分析和边缘检测原理，对雷达反射率数据进行处理，有效地识别出对流云回波区域，进而反演对流降水，精细化分析其和闪电的相关关系。选取了南京2009年7月6—7日的一次强雷暴降水过程中对流活动较剧烈的180 min为例，对采自南京龙王山雷达站的真实数据进行了算法识别分析，反演得到对流降水，统计6 min时间间隔内的闪电频数与同期降水进行相关分析，得到该时段中每次闪电所表征的降水量（RPF）的范围在7.47×106～4.46×107 kg，平

Analysis of Convective Precipitation and Lightning Based on Multi-scale Wavelet Edge Detection

Based on the concept of the multi-scale wavelet edge detection,an algorithm is presented to process the radar reflectivity data,so to identify convective cloud echoes effectively and retrieve convective precipitation.Taking a severe thunderstorm with heavy precipitations happened in Nanjing between 6 and 7 July 2009 as an example,a case study is conducted,focusing on the 180 minutes with relatively dense lightning flashes and severe precipitation.The convective cloud echo areas are then recognized by means of the multi-scale wavelet edge detection algorithm with the radar reflectivity data from Longwang station every 6 minutes.The corresponding convective precipitation is inversed through Z-I relation.The lightning flashes in the same 6 minutes are calculated,so the relation between convective precipitation and lightning can be analyzed.Results show that Rain Yields per flash(RPF) ranges from 7.47×106 to 4.46×107 kg,with average value being 1.72×107 kg;the non-linear curve fitting equation of precipitation intensity and lightning frequency is established.