摘要
自中中新世以来,特提斯海道和巴拿马海道的开合状态可能直接影响了大西洋经圈翻转流(AMOC)的强度和空间形态演变。但是,当前对这两处关键的中低纬度海道与AMOC之间联系的系统性研究较少。本研究基于中中新世时期的边界条件,利用耦合气候模式开展了中中新世气候模拟试验,以及特提斯海道和巴拿马海道先后关闭的敏感性试验。模拟结果显示,开放的特提斯海道和巴拿马海道分别为热带印度洋和太平洋海水进入北大西洋提供了“捷径”,同时分别向北大西洋输运高盐度海水和低盐度海水,对AMOC强度的变化起着相反的作用。特提斯海道开放增强了AMOC,这抵消了巴拿马海道开放导致的对AMOC的减弱。这两处中低纬度海道的关闭均能引起全球海表温度的南北不对称响应,分界线大致位于巴拿马海道所在纬度。本研究表明,只有特提斯海道和巴拿马海道关闭时,才会形成现代意义上的AMOC空间结构,因此这两处中低纬度海道的关闭时间对研究AMOC演变具有重要意义。
Since the Middle Miocene,the opening and closing of the Tethys and Panama seaways may have directly affected the intensity and spatial morphology of the Atlantic Meridional Overturning Current(AMOC).However,systematic studies on the connection between the two key mid-and low-latitude seaways and the AMOC are few.Based on the boundary conditions of the Middle Miocene,we conducted a Middle Miocene climate simulation experiment using a coupled climate model and a sensitivity experiment of the successive closure of the Tethys and Panama seaways.Results show that the openings of Tethys and Panama seaways provided"shortcuts"for tropical Indian and Pacific Ocean waters to enter the North Atlantic,respectively,and transported high-salinity and low-salinity seawater to the North Atlantic,respectively,which played opposite roles in the change of AMOC intensity.The opening of the Tethys Seaway enhanced the AMOC,which offset the weakening of the AMOC caused by the opening of the Panama Seaway.The closure of these two mid-and low-latitude seaways could cause a north-south asymmetric response of global sea surface temperature,and the dividing line was roughly located at the latitude of the Panama Seaway.This study showed that the modern spatial structure of AMOC could be formed only when the Tethys Seaway and the Panama Seaway were closed.Therefore,the closure time of these two mid-and low-latitude seaways is of great significance for studying the evolution of AMOC.
作者
魏吉林
刘海龙
郑伟鹏
林鹏飞
赵彦
WEI Jilin;LIU Hailong;ZHENG Weipeng;LIN Pengfei;ZHAO Yan(State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Laoshan Laboratory,Qingdao 266237,China;Earth System Numerical Simulation Science Center,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;Key Laboratory of Continental Collision and Plateau Uplift,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China)
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2024年第4期32-40,共9页
Marine Geology & Quaternary Geology
基金
国家重点研发计划项目课题“关键构造事件影响气候转型的数值模拟和机理分析”(2023YFF0803904)。
关键词
大西洋经圈翻转流
中中新世大暖期
淡水输运
巴拿马海道
特提斯海道
Atlantic Meridional Overturning Circulation(AMOC)
Middle Miocene Climatic Optimum(MMCO)
freshwater transport
Panama Seaway
Tethys Seaway
