基于多尺度小波边缘检测的对流降水和闪电分析  

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

作　　者：徐鸣一[1,2] 王振会[1,2] 潘佳文 樊荣[1,2] 植耀玲[1,2] 李博 邵程远[1,2] 

机构地区：[1]南京信息工程大学气象灾害省部共建教育部重点实验室 [2]南京信息工程大学大气物理学院,南京210044

出　　处：《气象科技》2012年第1期100-106,共7页Meteorological Science and Technology

基　　金：公益性行业科研专项(GYHY200806014)资助

摘　　要：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180min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6min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7.47×106～4.46×107 kg,平均值为1.72×l07 kg。通过非线性回归近似拟合可以得到南京地区这一时段对流性天气中降水强度、总降水量和闪电频数的回归方程。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 4.46×10^7 kg,with average value being 1.72×10^7 kg;the non-linear curve fitting equation of precipitation intensity and lightning frequency is established.

关 键 词：对流降水 闪电 小波分析 边缘检测 

分 类 号：P458.121[天文地球—大气科学及气象学]