| DOI: | 10.1007/s00382-011-1249-0
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| Scopus记录号: | 2-s2.0-84868141420
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| 论文题名: | Characterising meridional overturning bistability using a minimal set of state variables |
| 作者: | Sijp W.P.
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| 刊名: | Climate Dynamics
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| ISSN: | 9307575
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| 出版年: | 2012
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| 卷: | 39, 期:2017-09-10 | | 起始页码: | 2127
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| 结束页码: | 2142
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| 语种: | 英语
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| 英文关键词: | AMOC
; Atlantic
; Atlantic meridional overturning circulation
; Bistability
; Box model
; Climate change
; Convection shutdown
; Critical points
; Deep sinking
; Gulf stream shutdown
; Halocline catastrophe
; Limit point
; NADW formation
; NADW shutdown
; Non-linear system
; Non-linear theory
; North Atlantic deep water
; Poleward heat transport
; Saddle nodes
; Two stable states
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| 英文摘要: | A close approximation of key state variables and salt fluxes for both the North Atlantic Deep Water (NADW) "on" and "off" states in a General Circulation Model (GCM) is constructed, yielding a natural stability condition. Here, stability is linked to the effect of feedbacks on infinitesimal salinity anomalies on the average Atlantic salinity. The stability condition simply states that the total advective salt feedback must be negative in each steady state, ensuring stability by damping the growth of infinitesimal salinity perturbations. However, a decomposition of the salt feedback into three components shows that only the interaction between the mean salinity and infinitesimal perturbations of the meridional flow have the potential to render a state unstable, holding the key to state transitions. In contrast, the interaction between the mean meridional flow and infinitesimal salinity perturbations yields a negative (stabilising) component feedback. Similarly, the gyre salt flux also stabilises the overturning states. Furthermore, the nodes limiting the "on" and "off" state regimes in the GCM can be accurately computed based on linear fits of basic state variables and the gyre salt flux. It is shown that the NADW "on" state closest to collapse must be contained within a neighbourhood of fresh water exporting states. Finally, the role of temperature in the bistability structure is elucidated. © 2011 Springer-Verlag. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/55101
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| Appears in Collections: | 过去全球变化的重建
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作者单位: | Climate Change Research Centre (CCRC), University of New South Wales, Sydney, NSW 2052, Australia
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| Recommended Citation: | |
Sijp W.P.. Characterising meridional overturning bistability using a minimal set of state variables[J]. Climate Dynamics,2012-01-01,39(2017-09-10)
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