DOI: 10.1175/JCLI-D-13-00264.1
Scopus记录号: 2-s2.0-84896082741
论文题名: Why is the AMOC monostable in coupled general circulation models?
作者: Liu W. ; Liu Z. ; Brady E.C.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 6 起始页码: 2427
结束页码: 2443
语种: 英语
Scopus关键词: Atmospheric turbulence
; Climate models
; Convergence of numerical methods
; Experiments
; Feedback
; Tropics
; Water
; Atlantic meridional overturning circulations
; Community climate system model
; Coupled general circulation models
; Freshwater transports
; Meridional overturning circulations
; Ocean circulation
; Stability indicators
; Thermocline circulation
; Oceanography
; air-sea interaction
; atmospheric general circulation model
; oceanic circulation
; overturn
; salinity
; sea surface temperature
; thermocline
; Atlantic Ocean
; Atlantic Ocean (South)
英文摘要: This paper is concerned with the question: Why do coupled general circulation models (CGCM) seem to be biased toward a monostable Atlantic meridional overturning circulation (AMOC)? In particular, the authors investigate whether the monostable behavior of the CGCMs is caused by a bias of model surface climatology. First observational literature is reviewed, and it is suggested that the AMOCis likely to be bistable in the real world in the past and present. Then the stability of the AMOC in the NCAR Community Climate System Model, version 3 (CCSM3) is studied by comparing the present-day control simulation (without flux adjustment) with a sensitivity experiment with flux adjustment. It is found that the monostable AMOC in the control simulation is altered to a bistable AMOC in the flux-adjustment experiment because a reduction of the surface salinity biases in the tropical and northern North Atlantic leads to a reduction of the bias of freshwater transport in the Atlantic. In particular, the tropical bias associated with the double ITCZ reduces salinity in the upper South Atlantic Ocean and, in turn, the AMOC freshwater export, which tends to overstabilize the AMOC and therefore biases the AMOC from bistable toward monostable state. This conclusion is consistent with a further analysis of the stability indicator of two groups of IPCC Fourth Assessment Report (AR4) CGCMs: one without and the other with flux adjustment. Because the tropical bias is a common feature among all CGCMs without flux adjustment, the authors propose that the surface climate bias, notably the tropical bias in the Atlantic, may contribute significantly to the monostability of AMOC behavior in current CGCMs. © 2014 American Meteorological Society. 资助项目: NSF, National Science Foundation
; NSF, National Science Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51142
Appears in Collections: 气候变化事实与影响
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作者单位: Center for Climatic Research, Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI, United States; Laboratory of Climate, Ocean and Atmosphere Studies, Peking University, Beijing, China; Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO, United States
Recommended Citation:
Liu W.,Liu Z.,Brady E.C.. Why is the AMOC monostable in coupled general circulation models?[J]. Journal of Climate,2014-01-01,27(6)