DOI: 10.1007/s00382-011-1003-7
Scopus记录号: 2-s2.0-84855249590
论文题名: A minimal model for wind- and mixing-driven overturning: Threshold behavior for both driving mechanisms
作者: Fürst J.J. ; Levermann A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2012
卷: 38, 期: 2017-01-02 起始页码: 239
结束页码: 260
语种: 英语
英文关键词: Atlantic meridional overturning circulation
; Conceptual model
; Critical freshwater threshold
; Driving mechanism
; Meridional overturning circulation
; Northern sinking
; Overturning sensitivity
; Pycnocline depth
; Stability
英文摘要: We present a minimal conceptual model for the Atlantic meridional overturning circulation which incorporates the advection of salinity and the basic dynamics of the oceanic pycnocline. Four tracer transport processes following Gnanadesikan in Science 283(5410):2077-2079, (1999) allow for a dynamical adjustment of the oceanic pycnocline which defines the vertical extent of a mid-latitudinal box. At the same time the model captures the salt-advection feedback (Stommel in Tellus 13(2):224-230, (1961)). Due to its simplicity the model can be solved analytically in the purely wind- and purely mixing-driven cases. We find the possibility of abrupt transition in response to surface freshwater forcing in both cases even though the circulations are very different in physics and geometry. This analytical approach also provides expressions for the critical freshwater input marking the change in the dynamics of the system. Our analysis shows that including the pycnocline dynamics in a salt-advection model causes a decrease in the freshwater sensitivity of its northern sinking up to a threshold at which the circulation breaks down. Compared to previous studies the model is restricted to the essential ingredients. Still, it exhibits a rich behavior which reaches beyond the scope of this study and might be used as a paradigm for the qualitative behaviour of the Atlantic overturning in the discussion of driving mechanisms. © 2011 Springer-Verlag. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/55405
Appears in Collections: 过去全球变化的重建
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作者单位: Earth System Analysis, Potsdam Institute for Climate Impact Research and Institute of Physics, Potsdam University, Potsdam, Germany; Department of Geography and Earth System Sciences, Faculty of Sciences, Vrije Universiteit Brussel, Pleinlaan 2, Brussels, Belgium
Recommended Citation:
Fürst J.J.,Levermann A.. A minimal model for wind- and mixing-driven overturning: Threshold behavior for both driving mechanisms[J]. Climate Dynamics,2012-01-01,38(2017-01-02)