2007年6-7月江西雷电灾害综合分析

针对2007年6—7月江西雷电灾害特别严重的事实,从闪电定位资料、天气形势背景、对流不稳定指数,以及多普勒雷达回波特征等方面进行了相关对比分析。结果表明,异常频繁的闪电和较高的闪电密度,是造成江西2007年雷击人员伤亡重于往年、重于其他省份的重要因素。雷击死亡人数与闪电次数和闪电密度相关性较好,当闪电密度≥2.0次/km2时,发生雷击伤亡的可能性明显增加。副高位置不稳定、短波槽移动频繁以及不稳定指数偏强,是江西雷电频繁发生的天气背景条件。当雷达组合反射率强度>54 dBz、回波顶高>12 km、垂直积分液态含水量>40 kg/m2时,江西易产生强雷电。

Analysis of the Serious Lighting Hazard during June to July of 2007

Based on the lightning hazard happened in June and July of 2007 in Jiangxi province,the data of lightning location information,weather situations,convective instability index and Doppler radar are analyzed.The results indicate that the abnormal lightning frequency is the important factor causing more people died from lightning in Jiangxi than those in the other provinces and in 2007 than in the previous years.Death caused by thunder is related to the number of lightning and lightning density.The possibility of thunder casualties will increase significantly when the lightning density is larger than 2.0 km-2.The weather conditions for the frequent lighting happened in Jiangxi are unstable subtropic-high,frequent movement of short-wave trough and strong convective instability index.Serious thunderstorm will occur when echo reflectivity is larger than 54 dBz,echo height exceeds 12 km and VIL is more than 40 kg/m2.