Mechanisms of Atlantic Meridional Overturning Circulation(AMOC)Variability in a Coupled Ocean–Atmosphere GCM  

作　　者：Boyin HUANG ZHU Jiang YANG Haijun 

机构地区：[1]National Climatic Data Center, NOAA, Asheville, NC 28801, USA [2]Laboratory for Climate and Ocean–Atmosphere Studies, and Department of Atmospheric and Oceanic Sciences,School of Physics, Peking University

出　　处：《Advances in Atmospheric Sciences》2014年第2期241-251,共11页大气科学进展（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 41176002)

摘　　要：The mechanisms involved in the variability of Atlantic Meridional Overturning Circulation （AMOC） are studied using a 2000-yr control simulation of the coupled Fast Ocean-Atmosphere Model （FOAM）.This study identifies a coupled mode between SST and surface heat flux in the North Atlantic at the decadal timescale,as well as a forcing mode of surface heat flux at the interannual timescale.The coupled mode is regulated by AMOC through meridional heat transport.The increase in surface heating in the North Atlantic weakens the AMOC approximately 10 yr later,and the weakened AMOC in turn decreases SST and sea surface salinity.The decreased SST results in an increase in surface heating in the North Atlantic,thus forming a positive feedback loop.Meanwhile,the weakened AMOC weakens northward heat transport and therefore lowers subsurface temperature approximately 19 yr later,which prevents the AMOC from weakening.In the forcing mode,the surface heat flux leads AMOC by approximately 4 yr.The mechanisms involved in the variability of Atlantic Meridional Overturning Circulation （AMOC） are studied using a 2000-yr control simulation of the coupled Fast Ocean-Atmosphere Model （FOAM）.This study identifies a coupled mode between SST and surface heat flux in the North Atlantic at the decadal timescale,as well as a forcing mode of surface heat flux at the interannual timescale.The coupled mode is regulated by AMOC through meridional heat transport.The increase in surface heating in the North Atlantic weakens the AMOC approximately 10 yr later,and the weakened AMOC in turn decreases SST and sea surface salinity.The decreased SST results in an increase in surface heating in the North Atlantic,thus forming a positive feedback loop.Meanwhile,the weakened AMOC weakens northward heat transport and therefore lowers subsurface temperature approximately 19 yr later,which prevents the AMOC from weakening.In the forcing mode,the surface heat flux leads AMOC by approximately 4 yr.

关 键 词：Atlantic Meridional Overturning Circulation AMOC variability coupled mode and forcing mode 

分 类 号：P732[天文地球—海洋科学]