North Atlantic subtropical mode water formation controlled by Gulf Stream fronts  

作　　者：Bolan Gan Jingjie Yu Lixin Wu Gokhan Danabasoglu R.Justin Small Allison H.Baker Fan Jia Zhao Jing Xiaohui Ma Haiyuan Yang Zhaohui Chen 

机构地区：[1]Frontier Science Center for Deep Ocean Multispheres and Earth System(FDOMES)and Physical Oceanography Laboratory,Ocean University of China,Qingdao 266100,China [2]Laoshan Laboratory,Qingdao 266200,China [3]National Center for Atmospheric Research,Boulder,CO 80305,USA [4]CAS Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China

出　　处：《National Science Review》2023年第9期208-217,共10页国家科学评论（英文版）

基　　金：supported by the National Natural Science Foundation of China(42276016,92258302 and 41922039);the Science and Technology Innovation Foundation of Laoshan Laboratory(LSKJ202202602 and LSKJ202202402);the National Key Research and Development Program of China(2019YFA0607001 and 2020YFA0608801);the Qingdao Post-Doctoral Grant(QDBSH20220202119);the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021205).

摘　　要：The North Atlantic Ocean hosts the largest volume of global subtropical mode waters(STMWs)in the world,which serve as heat,carbon and oxygen silos in the ocean interior.STMWs are formed in the Gulf Stream region where thermal fronts are pervasive and result in feedback with the atmosphere.However,their roles in STMWformation have been overlooked.Using eddy-resolving global climate simulations,we find that suppressing local frontal-scale ocean-to-atmosphere(FOA)feedback leads to STMWformation being reduced almost by half.This is because FOA feedback enlarges STMW outcropping,attributable to the mixed layer deepening associated with cumulative excessive latent heat loss due to higher wind speeds and greater air-sea humidity contrast driven by the Gulf Stream fronts.Such enhanced heat loss overshadows the stronger restratification induced by vertical eddies and turbulent heat transport,making STMW colder and heavier.With more realistic representation of FOA feedback,the eddy-present/rich coupled global climate models reproduce the observed STMWs much better than the eddy-free ones.Such improvement in STMWproduction cannot be achieved,even with the oceanic resolution solely refined but without coupling to the overlying atmosphere in oceanic general circulation models.Our findings highlight the need to resolve FOA feedback to ameliorate the common severe underestimation of STMWand associated heat and carbon uptakes in earth system models.

关 键 词：North Atlantic subtropical mode water Gulf Stream thermal fronts frontal-scale ocean-to-atmosphere feedback eddy-resolving coupled global climate model 

分 类 号：P731[天文地球—海洋科学]