近11年中国寒潮频发的机理分析  

Causes of China s frequent cold waves over the past 11 years

作　　者：胡宏博 黄艳艳[1,2] 戴金 赵钱飞 HU Hongbo;HUANG Yanyan;DAI Jin;ZHAO Qianfei(Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD),Nanjing University of Information Science&Technology,Nanjing 210044,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519080,China;Dalian Meteorological,Dalian 116000,China)

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心,江苏南京210044 [2]南方海洋科学与工程广东省实验室(珠海),广东珠海519080 [3]大连市气象台,辽宁大连116000

出　　处：《大气科学学报》2023年第6期864-875,共12页Transactions of Atmospheric Sciences

基　　金：国家电网有限公司科技项目(5180-20221280A-2-68-XG);国家自然科学基金资助项目(42305022)。

摘　　要：利用全国840个站点观测资料以及ERA5再分析资料,分析了过去63 a(1960—2022年)冬半年(前一年10月—当年4月)全国性寒潮频次的年代际变化特征。统计结果表明:在全球变暖背景下,寒潮频次的下降趋势在2012年发生了转折,2012—2022年呈现显著上升趋势。2012—2022年,乌拉尔山阻塞频率与全国性寒潮发生频次呈显著负相关。乌拉尔山阻高会抑制高空急流发生发展,大气经向环流减弱,北极内冷气团南下受阻,从而减少寒潮发生的频次。同时乌拉尔山阻高与东亚中高纬地区地面2 m温度经向分布联系紧密,乌拉尔山阻塞的频繁发生往往会出现更多的北极增温、中纬度地区降温的天气尺度现象。此外,北极增暖效应本身也与我国寒潮频次有显著的负相关,北极增暖会减小中高纬温度差,西风带减弱,进而减弱冷空气的输送。近11 a,乌拉尔山阻塞频率呈显著减少趋势,相应地,等熵面位涡经向梯度具有线性增加趋势,不利于阻塞高压的维持,伴随北极增暖效应也呈现出减弱态势,这样的大气环流配置有利于近年来我国寒潮频次的增加。In this study,using data from 840 observed stations and ERA5 reanalysis,the decadal variation characteristics of the nationwide cold wave frequency in the cold season over the past 63 years(1960—2022)were analyzed.The statistical results show the following:against the background of global warming,the decreasing trend of cold wave frequency reversed in 2012,then showed a significant increasing trend from 2012 to 2022.During the latter period,the Ural Mountain blocking frequency was significantly negatively correlated with the occurrence frequency of nationwide cold waves.The Ural Mountain blocking high inhibits the occurrence and development of high-altitude jet streams,weakens the zonal circulation of the atmosphere,and blocks the southward movement of cold air masses in the Arctic,in turn reducing the frequency of cold waves.At the same time,the Ural Mountain blocking high favors weakening the surface 2 m temperature gradient over mid-to-high-latitude Eurasia.The frequent occurrence of Ural Mountain blocking often leads to more weather-scale phenomena of Arctic warming and mid-latitude cooling.In addition,Arctic warming effect itself also has a significant negative correlation with China’s cold wave frequency.Arctic warming reduces the temperature difference between mid-to-high latitudes,and weakens the westerly belt,thus also weakening the transport of cold air.Over the past 11 years,the Ural Mountain blocking frequency has shown a significant decreasing trend.Correspondingly,the zonal gradient of potential vorticity on isentropic surfaces has a linear increasing trend,which is unfavorable for the maintenance of blocking highs.Along with this,the Arctic warming effect also shows a weakening trend.This atmospheric circulation configuration is conducive to China s increase of cold wave frequency in recent years.

关 键 词：年代际变化 寒潮 阻塞高压 高空急流 北极增暖 

分 类 号：P425.54[天文地球—大气科学及气象学]