2010—2019年镇海区雷暴活动时空分布特征分析

Analysis on the Temporal and Spatial Distribution Characteristics of Thunderstorm Activities in Zhenhai District from 2010-2019

以宁波市闪电监测定位系统(ADTD)雷电监测资料作为原始数据,调取了镇海辖区雷电监测所有数据。采用数理统计方法、Lightning Statistics程序、Photoshop和Surfer绘图技术,对镇海区2010—2019年间雷暴活动时空分布特征进行了分析。结果表明:镇海区雷电活动频繁,年平均有2000余次地闪过程,具有明显的季节性时间分布特征;年平均雷暴日35.4 d/a,属于多雷区;地闪密度均值Nc=7.03次/(a·km^(2)),其中庄市街道最高,达9.57次/(a·km^(2)),九龙湖镇最小,为3.66次/(a·km^(2));月平均分布主要集中在7—9月,占总地闪90.5%,时段平均分布则在午后至傍晚13:00—19:00之间,占总地闪55.6%,最高达240.2次/h;其中负闪占主导地位,占总地闪91.95%,强度亦最强;正闪主要发生在雷暴活动过程的消亡阶段。

Taking the lightning monitoring data of Ningbo city lightning monitoring and positioning system(ADTD)as the original data,all the lightning monitoring data of Zhenhai district are retrieved.Using mathematical statistics,lightning statistics program,Photoshop and surfer mapping technology,the temporal and spatial distribution characteristics of thunderstorm activities in Zhenhai district during 2010-2019 were analyzed.The results show that there are frequent lightning activities in Zhenhai district,and average about 2000 lightning activities every year.The annual average thunderstorm day is 35.4 d/a,which belongs to a multi thunderstorm area.The mean value of ground flash density is Nc=7.03 times/(a·km^(2)),of which Zhuang Street is the highest,reaching 9.57 times/(a·km^(2)),while Jiulonghu Town is the smallest,reaching 3.66 times/(a·km^(2)).The monthly average distribution is mainly concentrated from July to September,accounting for 90.5%of the total ground flash,and the time average distribution is between 13:00-19:00 in the afternoon,accounting for 55.6%of the total ground flash,and the maximum is 240.2 times/h.The negative lightning is dominant,accounting for 91.95%of the total ground lightning,and the intensity is also the strongest.The positive lightning mainly occurs in the extinction stage of thunderstorm process.