5月南极涛动对青藏高原西部夏季气温影响的诊断分析  

Influence of the Antarctic Oscillation in May on Temperature over the Western Tibetan Plateau in Boreal Summer

作　　者：张宇[1,2] 李清泉[1,2] 余锦华[1] 沈新勇[1,3] 毕淼[4] 吴清源 ZHANG Yu;LI Qingquan;YU Jinhua;SHEN Xinyong;BI Miao;WU Qingyuan(Key Laboratory of Meteorological Disaster,Ministry of Education/International Joint Laboratory on Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044;CMA Key Laboratory for Climate Prediction Studies,National Climate Centre,Beijing 100081;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082;CMA Economic Transformation of Climate Resources Key Laboratory,Chongqing Institute of Meteorological Sciences,Chongqing 401147)

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,南京210044 [2]中国气象局气候预测研究重点开放实验室,国家气候中心,北京100081 [3]南方海洋科学与工程广东省实验室(珠海),珠海519082 [4]中国气象局气候资源经济转化重点开放实验室,重庆市气象科学研究所,重庆401147

出　　处：《气象》2024年第3期344-356,共13页Meteorological Monthly

基　　金：第二次青藏高原综合科学考察研究(2019QZKK0208);国家重点研发计划(2022YFE0136000);国家自然科学基金项目(U2242207、42105037);中国科学院战略性先导科技专项(XDA20100304);中国气象局创新发展专项(CXFZ2022J039、CXFZ2023J003)共同资助。

摘　　要：青藏高原是全球气候变暖最敏感的地区之一,是北半球夏季最大的热源,其气候响应受到广泛关注。然而,有关南极涛动与青藏高原夏季气温的关系和机理知之甚少。为了研究南极涛动与青藏高原夏季气温的关系,基于1979—2020年英国东安哥拉大学气候研究中心(CRU)的逐月气温、美国国家海洋和大气管理局(NOAA)的逐月海表面温度和大气环流再分析数据以及南极涛动指数等数据,采用相关、回归、合成分析等方法进行研究。结果表明,北半球夏季青藏高原西部气温与5月南极涛动存在显著负相关,即当5月南极涛动异常偏弱时,夏季青藏高原西部气温异常偏高。其影响过程为,南极涛动为正位相时,在南印度洋中高纬地区出现“负-正-负”的经向“三极子”海温模态,该模态可持续到夏季,在印度洋形成异常的纬向-垂直环流,相应在热带西印度洋和东印度洋-海洋性大陆之间的降水异常导致热带正“偶极子”降水模态,通过该降水模态在青藏高原西部引起异常反气旋环流和下沉运动,有利于高原西部气温偏高。研究结果显示,海洋的热惯性在“延长”南极涛动影响过程中起着重要的桥梁作用,可为青藏高原夏季气温预测提供科学依据。The Tibetan Plateau(TP),which is regarded as one of the most sensitive areas to climate warming in the world and the largest heat source of the Northern Hemisphere in summer,has been widely concerned.However,there are few studies on the relationship and mechanism between the Antarctic Oscillation(AAO)and temperature in summer over the TP.Based on observation and reanalysis data such as CRU monthly temperature,NOAA global monthly sea surface temperature data(ERSSTv5),and AAO index from 1979 to 2020,this paper shows that there is a significant negative correlation between the temperature over the western TP in summer and the AAO in May through linear regression analysis and other methods.That is,when the AAO anomaly is positive in May,the temperature over the western TP in summer is abnormally high.The process of its influence is that when the AAO is in a positive phase,a“negative-positive-negative”meridional“Tripole”sea surface temperature mode appears in the mid to high latitudes of the southern Indian Ocean.This mode can last until summer,inducing the wind anomaly over the Indian Ocean in the zonal and vertical direction.The precipitation anomaly between the tropical western Indian Ocean and the eastern Indian Ocean-Maritime Continent leads to a tropical“Dipole”rainfall mode.As a response,abnormal anticyclone circulation and downward movement appear over the western TP,which is conducive to the high temperature there.The research results in this paper indicate that the thermal inertia of the ocean plays an important role as a bridge in the process of prolonging the influence of the AAO,and it can provide scientific basis for the prediction of summer temperature over the TP.

关 键 词：南极涛动 青藏高原 印度洋 气温 

分 类 号：P461[天文地球—大气科学及气象学]