基于雷达参量的湖北地闪预警方法及效果检验  

Early-Warning Method and Effect Test of Cloud-to-Ground Lighting Using Doppler Radar Data Parameters in Hubei Province

作　　者：苟阿宁 吴翠红[2] 袁延得[3] 冷亮 朱传林[4] 韩芳蓉[2] 吴涛[2] GOU Aning;WU Cuihong;YUAN Yande;LENG Liang;ZHU Chuanlin;HAN Fangrong;WU Tao(Institute of Heavy Rain,CMA,Wuhan 430205;Wuhan Central Meteorological Observatory,Wuhan 430074;Qinghai Meteorological Disaster Prevention Technology Center,Xining 810001;Hubei Lightning Protection Centre,Wuhan 430074)

机构地区：[1]中国气象局武汉暴雨研究所,武汉430205 [2]武汉中心气象台,武汉430074 [3]青海省气象灾害防御技术中心,西宁810001 [4]湖北省防雷中心,武汉430074

出　　处：《气象》2022年第7期878-890,共13页Meteorological Monthly

基　　金：国家自然科学基金项目(41620104009);2019年湖北省气象局研究型业务发展专项(2019YJ 01-1);中国气象科学研究院灾害天气国家重点实验室2021年开放课题(2021LASW-B03)共同资助

摘　　要：利用天气雷达、探空资料,采用成熟的雷暴识别外推技术,比较有、无地闪活动时的概率密度分布和隶属度特征差异,提取雷达参量,采用模糊逻辑原理建立临近1 h地闪预警方法。分析表明,-25~-10℃高度层最大反射率因子(REF)和回波顶高是湖北地闪预警的最佳因子,尤以REF_(-15℃)、REF_(-20℃)和REF_(-z25℃)表现最佳,REF_(-10℃)效果次之,垂直积分液态含水量对雷电指示意义较小,根据不同因子贡献不同给与了不等权重分配,并通过雷电样本阈值分布规律,采用动态权重系数进行细化,实现了地闪未来1 h的临近落区预报。利用每6 min滚动预报未来1 h(6 min间隔)的临近预报结果和实况进行1 km网格点对点综合评分,30 min击中率(POD)可达50%以上,临界成功指数(CSI)为30%左右,POD和CSI随预报时效缓慢降低。通过个例预报检验,发现该预报方法在大范围雷暴天气预报评分较高,而局地对流的预报评分偏低。该研究说明基于雷达参量的模糊逻辑地闪预警方法基本合理可靠,可用于湖北雷电短时临近自动预报预警及决策服务。Based on the weather radar and radiosonde data,a widely used thunderstorm identification and extrapolation algorithm is used in this paper to compare the characteristic difference of probability frequency and membership for thunderstorms with or without cloud-to-ground(CG)lightning activity,and a one-hour warning method is established on the principle of fuzzy logic by extracting the radar parameters.The analysis results show that the maximum radar reflectivities in the-25℃to-10℃layer and at the height of echo top(ET)are the best factors for CG warning in Hubei Province.In particular,REF_(-15℃),REF_(-20℃) and REF_(-25℃) have the best performance,followed by REF_(-10℃).By contrast,vertically integrated liquid is less indicative of lightning activity.Thus,according to the different contributions of these factors,the unequal weight distribution is given,and the dynamic weight coefficient is used to finally achieve the location forecast of CG lightning in the future one hour.In addition,the 1 km grid point-to-point verification is performed by using the 1 h(6 min interval)nowcasts and in-site observations,and the results indicate that the probability of detection(POD)can reach more than 50%in 30 min,and the critical success index(CSI)is about 30%.However,POD and CSI decrease slowly with the increasing lead time of forecasts.Through the test of individual forecast case,it is found that this method is more suitable for the large-scale thunderstorm system,but relatively poor for local convective system.This finding illustrates that the fuzzy logic CG lightning warning method based on radar parameters is reasonable and reliable,and can be used for automatic warning and decision-making service in Hubei Province.

关 键 词：地闪 临近预报 模糊逻辑 决策服务 

分 类 号：P412[天文地球—大气科学及气象学] P427