北大西洋涛动对欧洲北海与不列颠岛附近冬季闪电活动的影响  

Impact of the North Atlantic Oscillation on Lightning Activity over the North Sea and Britain in Europe during Winter

作　　者：于欣宏 张文娟[2] 周震强 戴国锟 郑栋[2] 张义军 YU Xinhong;ZHANG Wenjuan;ZHOU Zhenqiang;DAI Guokun;ZHENG Dong;ZHANG Yijun(Department of Atmospheric and Oceanic Sciences,Fudan University,Shanghai 200433;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081)

机构地区：[1]复旦大学大气与海洋科学系,上海200433 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081

出　　处：《大气科学》2025年第1期138-152,共15页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目42175090。

摘　　要：本文利用2010~2022年全球闪电定位网(World Wide Lightning Location Network,WWLLN)资料和1993~2022年ERA5再分析资料,研究了北大西洋涛动(North Atlantic Oscillation,NAO)对欧洲北海及不列颠岛附近区域(50°~66°N,20°W~15°E)冬季(12月和1月)闪电活动的影响。此外针对2014年冬季(2014年12月与2015年1月)的极端闪电活动,讨论了NAO对这一闪电异常现象的主要贡献和影响过程。结果表明,NAO是该区域冬季闪电活动最直接的气候影响系统,NAO指数与闪电数呈显著正相关。合成分析结果表明,在NAO正相位时该区域闪电活动明显增强。这是由于增强的冰岛低压和亚速尔高压加强了北大西洋急流,使急流轴偏向在北大西洋海面上加强,闪电与急流的遥相关位于北大西洋中部,说明急流的加速作用是在北大西洋海表的急流入口区促进气旋波的产生并且随急流轴向东移动。同时,NAO也使得欧洲西海岸附近海温升高、亚速尔高压输送水汽增多,促进了闪电活动的产生。2014年冬季(2014年12月至2015年1月)该区域出现了闪电异常增多的情况,闪电数量增加至平均闪电数量的数十倍,且与冬季平均态闪电数量的均值和概率分布具有明显差异。分析表明,偶极子—冰岛低压和亚速尔高压的极端变化是此次闪电活动异常的主要原因。NAO的极端正相位导致北大西洋急流、局地海温、水汽输送都向有利于极端对流产生的方向发展,进而在该区域产生了异常活跃的冬季闪电活动。This paper examines how the North Atlantic Oscillation(NAO)influences winter lighting activity over the European North Sea and Britain(50°N-66°N,20°W-15°E)using data from the World Wide Lightning Location Network(WWLLN)for 2010-2022 and ERA5 datasets for 1993-2022.The study aims to investigate the impact of NAO on the circulation system,sea surface temperatures,and its relationship with lightning activity.The results reveal that NAO is the primary climate system affecting winter lightning activity over the North Sea,with a significant positive correlation between the NAO index and lightning frequency.The composite analysis indicates that the positive phase of NAO enhances lightning activity.This is attributed to enhanced frontogenesis from the intensified North Atlantic Jet,rising sea surface temperatures along the west coast of Europe,and increased water vapor transportation by the Azores high.During the winter season from December 2014 to January 2015,an abnormal increase in lightning occurrences was observed along the western coast of Northern Europe.Lightning frequency soared several times above the mean,with the distribution differing significantly from the typical winter pattern at a 99%confidence level.The study attributes this to cyclonic circulation anomalies generated by the Icelandic low and the anticyclonic anomalies from the Azores high,which speed up the North Atlantic westerly jet,particularly in central North Atlantic.Located in the central part of the North Atlantic,this teleconnection highlights how the accelerated jet stream promotes the formation of cyclone waves at its entry point,propelling them eastward across the ocean surface.The extreme positive anomaly of NAO facilitates frontogenesis,elevates sea-surface temperatures,and enhances moisture transportation,resulting in intensified winter lightning activity in the winter.

关 键 词：闪电 北大西洋涛动(NAO) 亚速尔高压 北大西洋西风急流 北大西洋三极型海温 

分 类 号：P463[天文地球—大气科学及气象学]