2022年夏季西太平洋副热带高压异常强盛且稳定维持与长江中下游持续性极端高温事件  

The anomalously strong and persistent western Pacific subtropical high in summer 2022 in association with the extreme heatwaves in the middle and lower reaches of the Yangtze river

作　　者：陈蔚 管兆勇[2] 杨华栋[3] 王磊 CHEN Wei;GUAN Zhaoyong;YANG Huadong;WANG Lei(Jiangsu Meteorological Observatory,Nanjing 210008,China;Key Laboratory of Meteorological Disaster,Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044,China;Nanjing Innovation Institution for Atmospheric Sciences,Nanjing 210008,China)

机构地区：[1]江苏省气象台,南京210008 [2]气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心,南京信息工程大学,南京210044 [3]南京气象科技创新研究院,南京210008

出　　处：《气象学报》2025年第1期33-45,共13页Acta Meteorologica Sinica

基　　金：国家重点研究计划项目(2019YFC1510201)。

摘　　要：2022年夏季长江中下游地区发生了1960年以来最强的高温事件,其形成和维持与西太平洋副热带高压(WPSH)异常强盛有关。利用站点观测资料和再分析资料,通过对不同变量的诊断分析,研究了高温时段WPSH异常强盛且稳定维持的机制,得到如下结论:(1)在高温时段,长江中下游地区盛行比一般高温年更强的下沉运动,扰动垂直动力加热是长江中下游地区高温维持的主要因素。短波辐射通量表现为向下的异常,可通过向上的感热通量将热量由地面传输至近地层空气并促使其升温。(2)与一般高温年不同,2022年WPSH与南亚高压(SAH)重叠于长江中下游地区,有利于WPSH在大陆上空维持,为此次极端高温事件的出现提供了有利的环流条件。WPSH强度维持与局地负涡度的维持有关。一是扰动负涡度的垂直向下输送,二是相对涡度水平平流负异常。特别是,在长江中下游地区上空WPSH的维持,自上而下的负涡度的垂直输送起着极为重要的作用。(3)不同于一般高温年,WPSH在海洋上的主体部分的维持主要与180o附近赤道中太平洋海温异常偏低有关。而WPSH在大陆上的部分,其维持与菲律宾群岛附近对流活动关系密切,有利于长江中下游地区上空负涡度的维持。研究结果将有利于加深对WPSH变化成因的认识,为后续研究持续高温的成因提供理论支撑。The strongest high-temperature event since 1960 occurred in the middle and lower reaches of the Yangtze river in the summer of 2022,and its formation and maintenance are related to the anomalously strong Western Pacific Subtropical High(WPSH).Using station observational data,reanalysis data,and diagnostic analysis of different variables,the present study investigates the mechanism for the anomalously strong and stable maintenance of the WPSH during the high temperature period.Results are as follows:(1)During the high temperature period,stronger sinking movements are prevalent in the middle and lower reaches of the Yangtze river compared to that in typical high temperature years,and the perturbation vertical dynamic heating term is the main factor for maintaining high temperatures in this region.Anomalous downward shortwave radiation flux can lead to heat transfer from the ground to the lower atmosphere through upward sensible heat flux,promoting surface heating.(2)Unlike the situation in the typical high temperature years,the overlap of WPSH and South Asian High(SAH)in the summer of 2022 facilitated the maintenance of WPSH over the middle and lower reaches of the Yangtze river,providing a favorable circulation condition for the extreme high temperature event.The maintenance of WPSH intensity was related to local negative vorticity,i.e.,the downward transport of negative vorticity disturbance and the negative anomaly of horizontal advection of relative vorticity.Especially,the vertical transport of negative vorticity from top to bottom played a crucial role on maintaining the WPSH over the middle and lower reaches of the Yangtze river.(3)Unlike that in typical high temperature years,the maintenance of the WPSH oceanic core was mainly related to anomalously low sea surface temperature near 180°around the equatorial central Pacific.The maintenance of the continental part of the WPSH was closely related to convection near the Philippine Islands,which was favorable for maintaining negative vorticity over the middle a

关 键 词：极端高温 西太平洋副热带高压 维持机制 长江中下游 2022年 

分 类 号：P423[天文地球—大气科学及气象学]