江西省夏季负地闪时空差异性分布特征

利用2013—2022年负地闪资料和江西省ADTD闪电资料，挑选2016、2018、2019年为重点研究样本,首先剔除研究区域外原始资料，保障研究样本可靠性，其次采用非参数核密度估计法（Kernel Density Estimation,KDE），对不同年份雷电流强度概率进行估计，进而研究江西省夏季（6—8月）闪电活动时空分布差异性。结果表明，不同年份江西省夏季负地闪密度在空间分布上存在相似的规律性，南部密度相对北部更大。地闪密度较大位置的雷电流强度并不一定较大，2016、2019年夏季雷电流强度空间分布较为均匀，呈现显著的空间一致性特征。不同年份夏季负地闪频次日分布单峰值分布特征较为显著，活动最为频繁的时段为午后至傍晚，其中2020—2022年活动相对其他年份更为频繁。江西省夏季负地闪雷电流强度极大值概率分布存在明显规律，有90%以上的概率大于-100 kA。

Temporal and spatial distribution characteristics of negative ground flashes in summer in Jiangxi Province

Based on the white paper of lightning prevention in Jiangxi Province from 2013 to 2022 and the lightning data from ADTD in Jiangxi Province, the year of 2016, 2018 and 2019 were selected as the key research samples. The original data outside the study area was eliminated to ensure the reliability of the study sample firstly, and then the nonparametric Kernel Density Estimation (KDE) algorithm was used to estimate the probability of lightning current intensity in different years. Finally, the temporal and spatial distribution of lightning activity in Jiangxi Province in summer was studied. The results showed that the spatial distribution of negative cloud to ground flash density in Jiangxi Province in summer in different years presented similar regularity, and the density in the south was higher than that in the north. At the same time, the lightning current intensity at locations with high ground flash density was not necessarily strong. For the summer of 2016 and 2019, the spatial distribution of lightning current intensity was relatively uniform, with significant spatial consistency characteristics. The daily distribution of negative cloud to ground lightning frequency in summer in different years presented a significant single peak. The lightning activity occurred frequently between afternoon and evening, especially during 2020 to 2022. The probability distribution of the maximum value of negative lightning current intensity in Jiangxi Province in summer exhibited obvious patterns, with more than 90% of the negative lightning current intensity not exceeding -100 kA.