青藏高原东北边缘地带2017-2020年地闪时空分布特征  

Temporal and spatial distribution characteristics of cloud-to-ground lightning flashes in the northeastern verge of Tibetan Plateau from 2017 to 2020

作　　者：唐国瑛 李丰全 王莺[1] 马莉 TANG Guoying;LI Fengquan;WANG Ying;MA Li(Institute of Arid Meteorology of CMA,Key Laboratory of Arid Climatic Change and Disaster Reducing of Gansu Province,Key Laboratory of Arid Climatic Change and Disaster Reducing of CMA,Lanzhou 730020,China;Wuhan NARI Limited Liability Company of State Grid Electric Power Research Institute,Wuhan 430074,China;Lanzhou Central Meteorological Observatory,Lanzhou 730020,China)

机构地区：[1]中国气象局兰州干旱气象研究所,甘肃省干旱气候变化与减灾重点实验室,中国气象局干旱气候变化与减灾重点实验室,甘肃兰州730020 [2]国网电力科学研究院武汉南瑞有限责任公司,湖北武汉430074 [3]兰州中心气象台,甘肃兰州730020

出　　处：《干旱气象》2022年第5期849-856,共8页Journal of Arid Meteorology

基　　金：国家自然基金(U2142208);甘肃省自然科学基金(20404099);干旱气象科学研究基金(IAM202121)共同资助。

摘　　要：青藏高原东北边缘地带是强对流天气多发区,雷电灾害频发。利用2017—2020年甘肃省ADTD(the advanced toa and direction system)闪电定位资料,对青藏高原东北边缘地带地闪频次、雷电流强度和地闪密度的时空分布特征进行分析,以便了解该地区地闪活动规律。结果表明:2017—2020年青藏高原东北边缘地带年平均地闪频数为2.71万余次,负、正地闪数分别占总闪数的84.27%和15.73%。地闪数月际变化呈明显的“单峰”特征,夏季闪电活动最强,占全年70.11%;春秋次之,冬季最弱。日变化亦呈“单峰”型,总闪和负地闪峰值出现在北京时10:00—12:00,正地闪峰值比负地闪峰值滞后约1 h。4—10月月平均正地闪数远少于负地闪,但正地闪的月平均电流强度却是负地闪的1.56倍。地闪密度大于0.24次·km-2·a-1的高值区主要出现在兰州市永登县,甘南藏族自治州碌曲县南部、玛曲县的西北部和东南部及合作市一带,天水市张家川回族自治县,庆阳市华池县、环县、镇原县、庆城县,陇南市南部和文县。正地闪高发区集中出现在玛曲县和碌曲县大部、定西市与甘南州交界处及庆阳市中南部。通过对比地闪密度与降水量之间的关系,认为青藏高原东北边缘地带的闪电活动与降水量在时空分布上有较好的一致性。The convective weather and lightning disasters occurred frequently in the northeastern verge of Tibetan Plateau.In order to analyze the characteristics of cloud-to-ground(CG) lightning flashes,the CG location data and daily precipitation collected by the advanced toa and direction(ADTD)system of Gansu Provincial Meteorological Administration and CIMISS during 2017-2020 are used to investigate the spatial and temporal characteristics of the CG lightning frequency,current intensity and the CG flashes density in the northeastern verge of Tibetan Plateau,and the relationship between the CG flashes density and precipitation.The results show that the annual average number of the CG lightning in this region in recent four years was about 2.71×104times.The annual average negative CG and positive CG lightning accounted for 84.27% and 15.73% of the total CG lightning flashes,respectively.The monthly distribution of the CG lightning flashes presented a single-peak pattern.Specifically,the CG lighting flashes mainly occurred in summer,which accounted for 70.11% of the CG lightning in the whole year.In spring and autumn,the percentage of the CG lightning was less than that in summer,and in winter the number was least.The diurnal distribution of the CG lightning frequency also showed a single peak.The peak value of the total CG and negative CG lightning occurred mainly from 10:00 BST to 12:00 BST in a day.The occurring time of peak value for positive CG lightning lagged one hour than the negative CG lightning.Although the number of monthly-averaged positive CG lightning was much less than that of negative CG lightning from April to October,the ratio of average current intensity of positive CG lightning flashes to that of negative CG flash was 1.56.The CG lightning flashes density greater than 0.24 fl·km-2·a-1concentrated in Yongdeng County of Lanzhou,Luqu County,Maqu County and Hezuo City in Gannan Tibetan Autonomous Prefecture,Zhangjiachuan County in Tianshui City,Huachi County,Huan County,Zhenyuan County and Qingcheng Cou

关 键 词：地闪 正地闪 时空分布 青藏高原东北边缘地带 降水量 

分 类 号：P427.3[天文地球—大气科学及气象学]