江西省地闪特征及其与雷达特征量关系研究

利用2013—2020年3—9月江西省多普勒天气雷达和地闪观测资料，对地闪分布特征及其与雷达主要特征量之间的关系进行统计分析。结果表明：江西省地闪频数从东北到西南逐渐减小，其北部鄱阳湖平原为地闪频数高值区；地闪频数具有明显的季节变化和日变化特征，总地闪频数在16:00达到一天的峰值；地闪频数与低层（3km）雷达回波强度的关系可用对数拟合方程来描述，地闪频数与低层雷达回波面积的变化趋势正相关，回波越强相关性越强，但二者存在位相差，地闪增加先于回波面积增加的情况约占57%～60%，大多数情况下可在18min内发现两者均有增加；箱线图特征显示，随着回波强度增大,地闪发生时的回波伸展高度相应减小，而回波厚度略增大，从而得出不同强度回波的地闪发生格点周围10km半径范围的雷达回波特征。

Research on the Characteristics of Cloud-to-Ground Lightning and Its Relationship with Radar Characteristics in Jiangxi Province

Using the Doppler weather radar and cloud-to-ground (CG) lightning observation data in Jiangxi Province from March to September in 2013-2020, we carried out a statistical analysis on the distribution characteristics of lightning and its relationship with the main features of radar. The results show that the CG lightning frequency in Jiangxi Province gradually decreases from the northeast to the southwest, and the Poyang Lake Plain in the north is the area with high CG lightning frequency. The CG lightning frequency has obvious seasonal and diurnal variation characteristics, and the total CG lightning frequency reaches the peak of one day at 16:00 BT. The relationship between CG lightning frequency and the low-level (3 km) radar echo intensity can be described by a logarithmic fitting equation. The number of CG lightning frequency is positively correlated to the variation trend of the low-level (3 km) radar echo area, and the stronger the echo, the stronger the correlation. However, there is a phase difference between the two, and the increase of the CG lightning frequency precedes the increase of the echo area by about 57%-60%. In most cases, the increase in both of CG lightning frequency and echo area can be found within 18 minutes. The boxplot features show that with the increase of the echo intensity, the extension height of the echo is lowered correspondingly, but the echo thickness is added slightly. Thus, the radar echo characteristics of the 10 km radius range around the CG lightning occurrence grid point, where the radar echo intensities are different, are obtained.