强热带风暴“玛娃”(1716)的闪电特征分析  

Analysis of Lightening Characteristics with Severe Tropical Storm Mawar(1716)

作　　者：李敏勋 余益君 邓纯 姚秋芳 曾莉茗 黎崇冠 LI Minxun;YU Yijun;DENG Chun;YAO Qiufang;ZENG Liming;LI Chongguan(Meizhou Early Warning Center,Meizhou 514021;Meizhou Meteorological Service,Meizhou 514700;Meixian District Early Warning Center,Meizhou 514700)

机构地区：[1]梅州市突发事件预警信息发布中心,广东梅州514021 [2]梅州市气象局,广东梅州514700 [3]梅县区突发事件预警信息发布中心,广东梅州514700

出　　处：《广东气象》2024年第6期23-28,共6页Guangdong Meteorology

基　　金：广东省气象局科学技术研究项目(GRMC2023Q32)。

摘　　要：为了解热带气旋(TC)登陆过程中的地闪特征,利用广东地闪定位、广东省天气雷达拼图、FY-2E卫星红外亮温(TBB)和东源探空等数据对2017年9月3日登陆广东的强热带风暴“玛娃”(1716)进行分析,结果表明:“玛娃”过程监测到地闪频数45010fl,其中正闪频数4749fl;地闪频数在登陆后减少约40%,可能与“玛娃”登陆后持续减弱有关。地闪活动主要集中于TC前进方向左侧,呈明显的非对称结构。TC登陆前后闪电活动都主要发生在外雨带,且占据主导地位,闪电活动在登陆后有向TC中心内收的趋势;过程地闪频数峰值出现在“玛娃”登陆前2h;登陆后地闪频数迅速减少,但正闪比例明显上升。“玛娃”登陆前后闪电活跃区域与强回波区域较为重合。云顶低亮温区域出现在外雨带,与地闪活跃区域有很好的对应关系,且闪电多发生于云顶亮温小于200K范围区域附近。500hPa以下的温度廓线基本在5℃范围内,湿层深厚,呈明显的不稳定层结特征。地闪活动出现的密集时段伴随着强的垂直风切变。In order to understand the characteristics of cloud-to-ground(C-G)lightning during the landfall of tropical cyclones,this paper analyzed the severe tropical cyclone Mawar that made landfall in Guangdong on September 3,2017 by employing lightning locations and weather radar mosaics for the province,the infrared brightness temperatures(TBB)from the FY-2E weather satellite and radiosonde data at Dongyuan.The results are shown as follows.During the visit of Mawar,a total of 45010 flashes of C-G lightning were detected,of which 4749 flashes were positive lightning.After landfall,the C-G lightning decreased by about 40%,possibly related with the persistent weakening of Mawar.The C-G lightning was most active on the left side of the storm's moving direction and showed a significantly asymmetric structure.In the time both before and after the landfall,lightning mainly occurred in the outer rain band and took up a dominant role.After landfall,lightning tended to shrink inwards to the eye.For the whole cycle of landfall,the C-G lightning peaked in frequency two hours before landfall.It decreased rapidly after it,but the proportion of positive flashes rose significantly.It was found that the active lightning zone was much coincided with the strong echo zone across the landfall point of Mawar.The zone of low cloud-top TBB appeared in the outer rain band,corresponding well with the zone of active C-G lightning,with the flashes mainly taking place around the area where the cloud-top TBB was lower than 200 K.Below the level of 500 hPa,temperature profiles were generally within the range of 5℃where there was a thick and moist layer,being much unstable in stratification.Frequent C-G lightnings were accompanied by the presence of a severe vertical wind shear.

关 键 词：天气学 地闪频数 雷达回波 相当黑体亮温 强热带风暴“玛娃” 广东 

分 类 号：P44[天文地球—大气科学及气象学]