甘肃和广东2008～2011年闪电特征对比

Comparative Analysis on Characteristics of Lightning over Gansu and Guangdong Areas

利用2008～2011年甘肃和广东地区闪电定位仪资料,得到了两地闪电的时间变化特征、强度变化特征和闪电密度分布,并分析两地存在的差异。结果表明:甘肃地区年平均发生的闪电频数远小于广东地区,且闪电的电流强度较广东地区小;两地闪电均以负闪占绝大多数,但正负闪的比例却不同,甘肃和广东负闪频数分别是正闪频数的15.5倍和20.5倍;两地均在每年的6～9月为闪电高发期,广东地区在6月出现一个闪电频数的明显跃增并达到全年最大值,闪电频数出现递增的时间较甘肃早,在不同的季节内,两地的闪电比例存在差异,且正、负闪比例也不同;甘肃地区总闪电频数日变化呈单峰单谷型,而广东地区总闪电的日变化趋势呈3峰震荡型;甘肃地区(兰州市)的平均闪电密度远小于广东地区(广州市)。

The temporal variation,intensity change and density distribution of lightning in Gansu and Guangdong areas were analyzed respectively by using the data of lightning locators in the two provinces,at the same time,the differences of lightning characteristcs in two places were also analyzed.The results show that the annual mean lightning frequency in Gansu is much smaller than that in Guangdong,and the current intensity of lightning in Gansu is weaker than that in Guangdong;Negative lightning are in the majority in both area,but the percentage are not the same,the frequency of negative lightning is 15.5 times of positive lightning in Gansu and 20.5 times in Guangdong;There is a high occurring period from June to September each year for lightning in both area.Besides,lightning frequency increased obviously and reached the maximum in June in Guangdong every year,the increase of lightning frequency in Guangdong started earlier than that in Gansu.The percentage of lightning are not the same in different seasons in both areas.Daily variation of lightning frequency presented a single peak and single valley in Gansu,but three peaks occured in Guangdong.The mean lightning density in Gansu（Lanzhou） is much smaller than that in Guangdong（Guangzhou）.