西藏羊八井地区的闪电活动特征  

Characteristics of Lightning Activities in Yangbajing Region of Tibet

作　　者：王俊芳[1,2] 曹冬杰[1] 卢红[3] 王东方[1] 

机构地区：[1]中国科学院大气物理研究所中层大气与全球环境探测重点实验室,北京100029 [2]中国科学院研究生院,北京100049 [3]中国科学院高能物理研究所粒子天体物理重点实验室,北京100049

出　　处：《高原气象》2011年第3期831-836,共6页Plateau Meteorology

基　　金：国家自然科学基金项目(40774083)资助

摘　　要：利用2009年夏季在西藏羊八井国际宇宙线观测站获取的快、慢天线闪电电场变化资料,分析了该地区闪电活动的基本特征。结果表明,闪电主要发生在6～9月,其中8月最多,占闪电总数的58.2%。就日变化而言,主要发生在下午,发生于17:00～19:00的闪电个数占闪电总数的65.1%。闪电频数最大值为9fl.min-1,平均值为1fl.min-1。2009年观测到的地闪全是负地闪,占闪电总数的14.6%。对地闪的统计发现,22.1%的地闪仅有一次回击。地闪首次回击之前放电过程持续时间的几何平均值为122.2ms,闪击间隔的几何平均值是32.1ms,高达84.5%的多回击地闪的继后回击峰值大于首次回击峰值。The characteristics of lightning are analyzed using the data of fast and slow antennas in International Cosmic Ray Observatory of Yangbajing in 2009.It is found that the lightning activities mainly occurred from late June to early September with a single percent peak of 58.2% in August.The diurnal variations of lightning activities show that the most of lightning easily occur in the afternoon and the percent of lightning activity from 17：00 to 19：00 is 65.1%.The maximum flash rate is 9 fl·min-1 and the average value is 1 fl·min-1.14.6% of lightning are cloud-ground flash and all are negative cloud-ground flash.From cloud-ground flash analysis,it is found that 22.1% of cloud-ground flash just have one return stroke.The percent of only one stroke of lightning is 22.1%.For cloud-ground flash the geometric mean of discharge duration before the first return stroke is 122.2 ms,the geometric mean of interstroke interval is 32.1 ms and for 84.5% of cloud-ground flash the peak electric field amplitudes of subsequent return strokes is larger than that of the first return stroke.

关 键 词：西藏羊八井地区 闪电 地闪 

分 类 号：P427.32[天文地球—大气科学及气象学]