川藏铁路不同站点的闪电活动差异及长期变化趋势  

The Variations and Trends of Lightning Activity among Different Stations along the Sichuan-Xizang Railway

作　　者：朱可欣 张鸿波[1] 郄秀书[1,2] 孙竹玲 韦蕾 蒋如斌 袁善锋[1] 徐晨 ZHU Kexin;ZHANG Hongbo;QIE Xiushu;SUN Zhuling;WEI Lei;JIANG Rubin;YUAN Shanfeng;XU Chen(Key Laboratory of Middle Atmosphere and Global Environment Observation/Key Laboratory of Atmospheric Environment and Extreme Meteorology,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;University of Chinese Academy of Sciences,Beijing 100049)

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/大气环境与极端气象重点实验室,北京100029 [2]中国科学院大学,北京100049

出　　处：《大气科学》2025年第1期173-184,共12页Chinese Journal of Atmospheric Sciences

基　　金：第二次青藏高原综合科学考察研究项目2019QZKK0104。

摘　　要：本文利用全球闪电定位网(WWLLN)2010~2019年期间订正探测效率后的资料,对川藏铁路沿线的闪电活动时空分布特征及其长期变化趋势开展研究。结果表明:川藏铁路沿线的闪电活动在高原3000 m以下的成都西—雅安段和高原3000 m以上的雅安—拉萨段呈现明显的时空分布不连续特征。闪电活动总体上呈现东多、西少的空间分布模态,雅安—拉萨附近的年均闪电密度[约10 fl(10 km)^(-2)a^(-1),fl表示flashes]远小于成都西—雅安附近[约50 fl(10 km)^(-2)a^(-1)]。雅安—拉萨附近的闪电活动更早爆发、更晚结束,集中在5~11月份;而成都西—雅安附近则主要集中在6~10月份。雅安—拉萨附近的闪电日活动在下午至晚间16:00~20:00达到峰值,而成都西—雅安附近的闪电日活动大多在凌晨00:00~06:00达到峰值。对十年观测资料分析发现,川藏铁路沿线闪电活动的上升幅度明显高于下降幅度。铁路沿线大部分区域,尤其是青藏高原上的区域闪电活动长期变化几乎都呈现上升趋势[可超过14 fl(10 km)^(-2a)^(-1)],且多数上升幅度大于70%,其中拉萨站附近增幅超过150%;但成都西至雅安站附近却呈显著下降趋势[约10 fl(10 km)^(-2)a^(-1)],下降幅度约60%。The spatiotemporal distributions and trends of lightning activity along the Sichuan-Xizang Railway are investigated using data from the World Wide Lightning Location Network(WWLLN)for the period 2010-2019,considering the relative detection efficiency of the network.The results indicate that the temporospatial distributions over the Sichuan-Xizang Railway sections below 3000 m elevation of the Qinghai-Xizang Plateau(QXP)(from Chengdu west station to Yaan station)differ significantly from those above the 3000 m elevation(from Yaan station to Lhasa station).First,the spatial distribution of the mean flash density is higher in the eastern sections of the railway,averaging 50 fl(10 km)^(-2)a^(-1),than in the western sections,for which the mean flash density is 10 fl(10 km)^(-2)a^(-1).Second,the lightning activity around sections above the 3000 m elevation manifests earlier(in May)and ceases later(in November),whereas the lightning activity below 3000 m occurs from June to October.Third,the sections above the 3000 m elevation experience peak diurnal lightning activity in the afternoon(1600 BJT-2000 BJT),while the sections below the 3000 m elevation experience peak activity early in the morning(0000 BJT-0600 BJT).In terms of the long-term trends,the increase in the lightning density amplitude along the Sichuan-Xizang Railway is more pronounced than the decrease.Specifically,most areas of the railway above 3000 m elevation exhibit an upward trend in flash density[exceeding 14 fl(10 km)^(-2)a^(-1),indicating an increase of more than 70%].The lightning density around Lhasa station has increased by up to 150%.The stations below 3000 m(Chengdu west to Yaan station)show significantly different lightning densities,exhibiting a decreasing trend[approximately-10 fl(10 km)^(-2)a^(-1),a decrease of 60%].

关 键 词：川藏铁路 闪电活动 时空不均匀 长期变化趋势 

分 类 号：P435[天文地球—大气科学及气象学]