辽宁省一次强对流天气的地闪特征  

A Case Study of Cloud-to-Ground Lightning Activity on a Strong Convective Weather in Liaoning Province

作　　者：蒋大凯[1] 才奎志[1] 曲荣强[1] 

机构地区：[1]沈阳中心气象台,沈阳110015

出　　处：《气象》2010年第6期73-78,共6页Meteorological Monthly

基　　金：中国气象局气象新技术推广项目预报员专项(编号:CMATG2006Y02)资助

摘　　要：利用闪电定位系统、多普勒雷达和加密自动站资料对辽宁一次冷涡天气中暴雨、冰雹过程的地闪变化特征进行分析。结果表明,暴雨和冰雹过程均出现了地闪密集区,冰雹过程中正地闪占总地闪比例高于暴雨过程;暴雨过程以负地闪为主,主要分布在45 dBz以上的强回波区内,和暴雨持续时间相当,负地闪最密集区位于风暴的核心部位。负地闪频数比强回波面积提前30至70分钟到达峰值,对于短时暴雨预报预警具有一定意义。冰雹过程中,负地闪集中在雹云前部,正地闪位于雹云核心部位,与降雹区一致,正、负地闪发生区域分离。正地闪提前降雹30分钟左右发生,总地闪、正地闪频数在降雹前明显增加;降雹出现在总地闪、正地闪频数和强回波面积达到峰值及从峰值迅速下降时间段内;雹云减弱消散阶段总地闪次数减少但正闪增加。This paper analyzes the characteristics of cloud-to-ground（CG） lightning in rainstorm and hail event that caused by a cold vortex,by using data collected in lightning detection network,Doppler radar and intensive automatic weather stations.The results show that there are dense areas of CG lightning in the process of rainstorm and hail,and the proportion of positive CG lightning in hail is higher than in rainstorm; the negative CG lightning predominates in rainstorm,which is mostly located at the core area of rainstorm and mainly in the radar echo area of above 45 dBz,and its lasting time is equivalent to the duration of rainstorm.The negative CG lightning frequency and its growth rate reach the peak 30-70 min ahead of the area of strong radar echo,and it has a certain prediction significance for short-term rainstorm forecasting and early warning.In the hail process,negative CG lightning is concentrated in front of hail cloud,and the positive CG lightning is located at the core area of hail cloud,which is consistent with hail area,and the regions of positive and negative CG lightning begin to separate.The total number of CG lightning and the area of strong radar echo have a similar changing trend.Positive CG lightning occurs about 30 min ahead of hail.The total CG lightning and positive CG lightning frequencies are increasing considerably before hail.Hail occurs during the period that the total CG lightning,positive CG lightning and the area of strong radar echo reach the peak and decrease rapidly.The total CG lightning number decreases,but the positive CG lightning increases in the dissipating and weakening phase of hail cloud.

关 键 词：正、负地闪 回波强度 强对流 

分 类 号：P448[天文地球—大气科学及气象学]