Quantifying the Role of the Eddy Transfer Coefficient in Simulating the Response of the Southern Ocean Meridional Overturning Circulation to Enhanced Westerlies in a Coarse-resolution Model  

作　　者：Yiwen LI Hailong LIU Pengfei LIN Eric PCHASSIGNET Zipeng YU Fanghua WU 

机构地区：[1]School of Ocean Sciences,China University of Geosciences,Beijing 100083,China [2]Laoshan Laboratory,Qingdao 266237,China [3]Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China [4]Center for Ocean-Atmospheric Prediction Studies,Florida State University,Tallahassee 32306,Florida,USA [5]China Meteorological Administration,Beijing 100081,China

出　　处：《Advances in Atmospheric Sciences》2024年第9期1853-1867,共15页大气科学进展（英文版）

基　　金：supported by the National Key R&D Program for Developing Basic Sciences(2022YFC3104802);the National Natural Science Foundation of China(Nos.42306219 and 42106020);the Tai Shan Scholar Pro-gram(Grant No.tstp20231237);Part of computing resources are financially supported by Laoshan Laboratory(No.LSKJ202300301);Dr.Eric P.CHASSIGNET is supported by the CAS President’s International Fellowship Initiative(PIFI);NOAA Climate Program Office MAPP Program(Award NA15OAR4310088).

摘　　要：This study assesses the capability of a coarse-resolution ocean model to replicate the response of the Southern Ocean Meridional Overturning Circulation(MOC) to intensified westerlies,focusing on the role of the eddy transfer coefficient(κ).κ is a parameter commonly used to represent the velocities induced by unresolved eddies.Our findings reveal that a stratification-dependent κ,incorporating spatiotemporal variability,leads to the most robust eddy-induced MOC response,capturing 82% of the reference eddy-resolving simulation.Decomposing the eddy-induced velocity into its vertical variation(VV) and spatial structure(SS) components unveils that the enhanced eddy compensation response primarily stems from an augmented SS term,while the introduced VV term weakens the response.Furthermore,the temporal variability of the stratification-dependent κ emerges as a key factor in enhancing the eddy compensation response to intensified westerlies.The experiment with stratification-dependent κ exhibits a more potent eddy compensation response compared to the constant κ,attributed to the structure of κ and the vertical variation of the density slope.These results underscore the critical role of accurately representing κ in capturing the response of the Southern Ocean MOC and emphasize the significance of the isopycnal slope in modulating the eddy compensation mechanism.

关 键 词：eddy transfer coefficient mesoscale eddy parameterization enhanced westerlies Southern Ocean Meridional Overturning Circulation ocean model 

分 类 号：P731.27[天文地球—海洋科学]