南极海冰涛动对北半球夏季大气环流的影响  

Impacts of Antarctic Sea Ice Oscillation on Summer Atmospheric Circulation in the Northern Hemisphere

作　　者：王爽 吴其冈 刘师佐 梁涵洲 户元涛 康彩燕 包晓军 高艳 WANG Shuang;WU Qigang;LIU Shizuo;LIANG Hanzhou;HU Yuantao;KANG Caiyan;BAO Xiaojun;GAO Yan(Department of Atmospheric and Oceanic Sciences,Fudan University,Shanghai 200438;China Innovation Center of Ocean and Atmosphere System,Zhuhai Fudan Innovation Research Institute,Zhuhai 519000;School of Atmospheric Sciences,Nanjing University,Nanjing 210023;Naruida Technology Ltd.,Zhuhai 519000;Ningxia Meteorological Observatory,Yinchuan 750002)

机构地区：[1]复旦大学大气与海洋科学系,上海200438 [2]海气系统监测与预测创新中心/珠海复旦创新研究院,珠海519000 [3]南京大学大气科学学院,南京210023 [4]广东纳睿雷达科技股份有限公司,珠海519000 [5]宁夏气象台,银川750002

出　　处：《大气科学》2022年第6期1349-1365,共17页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目91837206;广东省引进创新创业团队项目2016ZT06G579。

摘　　要：南极海冰首要模态呈现偶极子型异常,正负异常中心分别位于别林斯高晋海/阿蒙森海和威德尔海。过去研究表明冬春季节南极海冰涛动异常对后期南极涛动(Antarctic Oscillation,AAO)型大气环流有显著影响,而AAO可以通过经向遥相关等机制影响北半球大气环流和东亚气候。本文中我们利用观测分析发现南极海冰涛动从5~7月(May-July,MJJ)到8~10月(August-October,ASO)有很好的持续性,并进一步分析其对北半球夏季大气环流的可能影响及其物理过程。结果表明,MJJ南极海冰涛动首先通过冰气相互作用在南半球激发持续性的AAO型大气环流异常,使得南半球中纬度和极地及热带之间的气压梯度加大,在MJJ至JAS,纬向平均纬向风呈现显著的正负相间的从南极到北极的经向遥相关型分布。对流层中层位势高度场上,在澳大利亚北部到海洋性大陆区域,出现显著的负异常,在东亚沿岸从低纬到高纬呈现南北走向的“-+-”太平洋—日本(Pacific-Japan,PJ)遥相关波列,其对应赤道中部太平洋及赤道印度洋存在显著的降水和海温负异常,西北太平洋至我国东部沿海地区存在显著降水正异常和温度负异常;低纬度北美洲到大西洋一带存在的负位势高度异常和北大西洋附近存在的正位势高度异常中心,构成一个类似于西大西洋型遥相关(Western Atlantic,WA)的结构,对应赤道南大西洋降水增加和南撒哈拉地区降水减少。从物理过程来看,南极海冰涛动首先通过局地效应影响Ferrel环流,进而通过经圈环流调整使得海洋性大陆区域和热带大西洋上方的Hadley环流上升支得到增强,海洋性大陆区域特别是菲律宾附近的热带对流活动偏强,激发类似于负位相的PJ波列,影响东亚北太平洋地区的大气环流,而热带大西洋对流增强和北传特征,则通过激发WA遥相关影响大西洋和欧洲地区的大气环流。以上两种通道将持续性MJJ至The primary mode of empirical orthogonal function of Antarctic sea ice is a dipole anomaly,with the positive and negative anomaly centers over the Bellingshausen/Amundsen Sea and the Weddell Sea,respectively.This dipole anomaly is known as the Antarctic sea ice oscillation or Antarctic dipole.Previous studies have shown that the Antarctic sea ice oscillation in austral winter and spring has a significant effect on the subsequent Antarctic oscillation(AAO)-type atmospheric circulation,which significantly impacts the Northern Hemisphere climate and East Asian summer monsoon.This empirical study further examines the remote effects of the May-June-July(MJJ)Antarctic sea ice oscillation on the boreal summer atmospheric circulation in the Northern Hemisphere and the associated physical processes.Results showed that the Antarctic sea ice dipole anomaly has good persistence around austral winter from MJJ to July-August-September,which triggers persistent AAO-like atmospheric responses in the troposphere and lower stratosphere with the increase in the pressure gradient between middle and high latitudes.Moreover,the latitudinal mean zonal wind exhibits a significant distribution of meridional teleconnection from the South Pole to the North Pole.In the middle troposphere,the 700-hPa geopotential height field exhibits significant negative anomalies from northern Australia to the maritime continent,a significant positive anomaly center near Japan,and a band-shaped negative anomaly near the Sea of Okhotsk and the Aleutian Islands when the atmosphere lags behind the sea ice anomaly by 0 to 2 months.It is another form of meridional teleconnection,except for the zonal wind.Significant negative precipitation and sea surface temperature anomalies are detected in the equatorial central Pacific and the Indian Ocean,and significant positive precipitation anomalies from the northern Maritime Continent to eastern coastal China.Furthermore,the negative geopotential height anomaly from the subtropical North America to the western Atlantic

关 键 词：南极海冰涛动 冰气相互作用 南极涛动 北半球 大气环流 北半球夏季 

分 类 号：P461[天文地球—大气科学及气象学]