青藏高原东北部地区闪电特征初步分析  

Preliminary Analyses on Some Characteristics of Flashes in Northeastern Qinghai-Xizang Plateau

作　　者：张荣[1,2] 张广庶[1] 王彦辉[1] 李亚珺[1] 武斌[1] 余海[1,2] 刘妍秀[1,2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所寒旱区陆面过程与气候变化重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《高原气象》2013年第3期673-681,共9页Plateau Meteorology

基　　金：国家自然科学基金项目(41075002;40775004);国家自然科学基金重点项目(41030960)共同资助;公益性行业科研专项(GYHY201006005-03)

摘　　要：利用VHF辐射源三维定位系统及快、慢天线资料,对青海大通地区5次雷暴过程中云闪、负地闪、正地闪的起始高度、持续时间、辐射源数目及正、负地闪云内放电过程的持续时间和回击次数进行了统计分析。研究表明,该地区闪电持续时间较短,平均<0.5s;正、负地闪首次回击发生前均有较长时间的云内放电过程,正地闪的云内放电过程持续时间略长于负地闪;负地闪的回击次数较少,平均为2.5次,其中40%的负地闪只有1次回击,而正地闪回击次数均为1次;云闪的起始高度最高,负地闪的起始高度低于云闪,正地闪的起始高度最低;云闪产生的辐射源数目最多,负地闪少于云闪,正地闪产生的辐射源数目最少。Some characteristics of lightning flashes in northeastern Qinghai-Xizang Plateau were analyzed u- sing the three-dimensional lightning locating system, fast and slow antennas. It is found that the duration of flashes is not long, averagely less than 0.5 s. Both the positive and negative cloud-to-ground flashes have long duration of intracloud discharge process before the first return stroke, and it is slightly longer for positive cloud-to-ground flashes. The average number of strokes per negative cloud-to-ground flash is 2.5, and 40 % of the negative cloud-to-ground flashes are single-stroke flashes, while all the positive cloud- to-ground flashes are single-stroke flashes. The average starting height of intracloud flashes is higher than the negative cloud-to-ground flashes, and that of the positive cloud-to-ground flashes is lower than the neg- ative cloud-to-ground flashes. Meanwhile, the average number of radiation sources generated by intracloud flashes is the largest, followed by negative cloud-to-ground flashes, and that of positive cloud-to-ground flashes is the smallest.

关 键 词：闪电 起始高度 辐射源 

分 类 号：P427.3[天文地球—大气科学及气象学]