广东地闪时空特征及与降水关系分析

利用2016—2020年粤港澳闪电定位数据和广东86个国家地面观测站逐小时降水资料，分析了广东地闪频次和地闪强度的时空分布特征，以及地闪与降水量、强降水频次之间的相关关系。结果表明：(1)广东逐月地闪频次与降水变化均呈双峰型分布，峰值在6和8月，两者相关系数达到0.95。日变化中，地闪频次高值集中在12:00—20:00,占比为61.4%;地闪频次与逐时雨量均为单峰型，峰值出现在15:00,两者相关系数0.90。(2)地闪密度大值区以广州为中心向四周递减，中心值达到33次/(km²·年)以上；地闪强度分布与地闪密度相反，地闪密度大的地区，其平均地闪强度小。(3)全省大部分地区地闪密度与降水量、强降水频次相关性强，而在粤东及粤北地区相关性较差。相较于降水量，地闪密度大值区与强降水频次的相关性更好；而地闪强度与降水量的相关性，比其与强降水频次相关性要更好。

Analysis of the Spatiotemporal Distribution Characteristics of Cloud-to-Ground Lightning and Their Relationship with Precipitation in Guangdong Province

Using the lightning location data from Guangdong province,Hong Kong and Macao and hourly precipitation data from 86 national surface observation stations in the province for the period from 2016 to 2020,this work analyzes the spatiotemporal distribution characteristics of the frequency and intensity of cloud-to-ground(to be referred to as“C-G”hereafter)lightning in Guangdong,as well as the relationship between the C-G lightning and the precipitation amount and intense precipitation frequency.The results are shown as follows.(1)For Guangdong,both the monthly frequency of the C-G lightning and precipitation variation show a bimodal distribution with the peaks in June and August respectively,which are correlated by a coefficient of 0.95.For the diurnal variation,high C-G lightning frequencies mainly happen between 12:00 and 20:00,taking up 61.4%of the total.Both the C-G lightning and hourly precipitation amount are unimodally distributed,with the peak at 15:00,and correlated by a coefficient of 0.90.(2)Centred at Guangzhou,a zone of dense C-G lightning,with the core value more than 33 times/(km;·year),decreases gradually outwards.The distribution of the C-G lightning intensity is the opposite of that of the C-G lightning density-the larger the latter,the smaller the former on average.(3)The C-G lightning density is better correlated with the precipitation amount and intense precipitation frequency in most parts than in the eastern and northern parts of the province.The zone of dense C-G lightning is better correlated with the intense precipitation frequency than with the precipitation amount,and the C-G lightning intensity is better correlated with the precipitation amount than with the intense precipitation frequency.