2006-2009年南京地区闪电活动分布特征

利用2006-2009年江苏省闪电监测定位系统资料,对南京地区闪电活动特征进行了分析,发现闪电集中发生在6-8月的12-20时,其他各月闪电频数较低,这主要是由于南京夏季对流活动频繁,且在午后至傍晚的时间段内,气温偏高,较易产生强对流的雷暴天气等原因造成的.南京地区大部分区域的平均雷击大地密度值介于2～6次/(km²·a)之间,平均雷击大地密度极大值中心出现在江宁区,平均雷击强度值介于5～40kA之间,南京长江大桥附近出现了平均雷击强度极大值的中心,最大值达75kA以上.地形地貌、下垫面性质、水汽条件等因素可能是导致上述特征的主因.所获得的闪电活动特征闪电参数在雷电防护、雷击风险评估等领域具有一定的应用价值.

Lightning distribution characteristics in Nanjing from 2006 to 2009

The monitoring data of Jiangsu Provincial Lightning Positioning System from 2006 to 2009 are used to analyze the characteristics of lightning activity in Nanjing.It is found that,most of the lightning happens at 12-20 P.M.in June-August and few happens in other months,because the convective activities frequently happen in summer in Nanjing and in the period of the midday to sunset,due to the always high temperature,which is easy to produce strong convective thunderstorm;The average density of lightning striking the earth is between 2-6 times/(km²·a) in most Nanjing area,and the maximum center is in Jiangning district.The average lightning strike intensity is between 5-40 kA,and the maximum center is near Nanjing Yangtze River Bridge,where the intensity is 75 kA or more.Topography,land surface properties,moisture conditions and other factors may be the main reason leading to the above characteristics.The lightning activity characteristics and lightning parameters obtained in this study are valuable in the lightning protection,lightning risk assessment and other areas.