title: Reduced interdecadal variability of Atlantic Meridional Overturning Circulation under global warming.
abstract: Interdecadal variability of the Atlantic Meridional Overturning Circulation (AMOC-IV) plays an important role in climate variation and has significant societal impacts. Past climate reconstruction indicates that AMOC-IV has likely undergone significant changes. Despite some previous studies, responses of AMOC-IV to global warming remain unclear, in particular regarding its amplitude and time scale. In this study, we analyze the responses of AMOC-IV under various scenarios of future global warming in multiple models and find that AMOC-IV becomes weaker and shorter with enhanced global warming. From the present climate condition to the strongest future warming scenario, on average, the major period of AMOC-IV is shortened from ∼50 y to ∼20 y, and the amplitude is reduced by ∼60%. These reductions in period and amplitude of AMOC-IV are suggested to be associated with increased oceanic stratification under global warming and, in turn, the speedup of oceanic baroclinic Rossby waves.
authors.affiliation: Polar Climate System and Global Change Laboratory, Nanjing University of Information Science & Technology, Nanjing 210044, China; chengjun@nuist.edu.cn zliu3@wisc.edu.
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI 53706; Nelson Center for Climatic Research, University of Wisconsin-Madison, Madison, WI 53706; Laboratory for Climate and Ocean-Atmosphere Studies, School of Physics, Peking University, Beijing 100871, China; chengjun@nuist.edu.cn zliu3@wisc.edu.
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton University, Princeton, NJ 08542;
authors.forename: Shaoqing
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92037.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Polar Climate System and Global Change Laboratory, Nanjing University of Information Science & Technology, Nanjing 210044, China;
authors.forename: Lina
authors.initials: L
authors.lastname: Dong
authors.affiliation: Polar Climate System and Global Change Laboratory, Nanjing University of Information Science & Technology, Nanjing 210044, China;
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Polar Climate System and Global Change Laboratory, Nanjing University of Information Science & Technology, Nanjing 210044, China;
authors.forename: Hongli
authors.initials: H
authors.lastname: Li
keywords: Atlantic Meridional Overturning Circulation; Rossby wave; global warming; interdecadal variability; oceanic stratification