DOI: 10.1007/s00382-012-1576-9
Scopus记录号: 2-s2.0-84891624449
论文题名: Meridional overturning circulation: Stability and ocean feedbacks in a box model
作者: Cimatoribus A.A. ; Drijfhout S.S. ; Dijkstra H.A.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 42, 期: 2017-01-02 起始页码: 311
结束页码: 328
语种: 英语
英文关键词: Atlantic
; Freshwater
; Meridional overturning circulation
; Salt-advection feedback
; Southern subtropical gyre
; Stability
英文摘要: A box model of the inter-hemispheric Atlantic meridional overturning circulation is developed, including a variable pycnocline depth for the tropical and subtropical regions. The circulation is forced by winds over a periodic channel in the south and by freshwater forcing at the surface. The model is aimed at investigating the ocean feedbacks related to perturbations in freshwater forcing from the atmosphere, and to changes in freshwater transport in the ocean. These feedbacks are closely connected with the stability properties of the meridional overturning circulation, in particular in response to freshwater perturbations. A separate box is used for representing the region north of the Antarctic circumpolar current in the Atlantic sector. The density difference between this region and the north of the basin is then used for scaling the downwelling in the north. These choices are essential for reproducing the sensitivity of the meridional overturning circulation observed in general circulation models, and therefore suggest that the southernmost part of the Atlantic Ocean north of the Drake Passage is of fundamental importance for the stability of the meridional overturning circulation. With this configuration, the magnitude of the freshwater transport by the southern subtropical gyre strongly affects the response of the meridional overturning circulation to external forcing. The role of the freshwater transport by the overturning circulation (M ov) as a stability indicator is discussed. It is investigated under which conditions its sign at the latitude of the southern tip of Africa can provide information on the existence of a second, permanently shut down, state of the overturning circulation in the box model. M ov will be an adequate indicator of the existence of multiple equilibria only if salt-advection feedback dominates over other processes in determining the response of the circulation to freshwater anomalies. M ov is a perfect indicator if feedbacks other than salt-advection are negligible. © 2012 Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54508
Appears in Collections: 过去全球变化的重建
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作者单位: Royal Netherlands Meteorological Institute, De Bilt, Netherlands; Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, Netherlands
Recommended Citation:
Cimatoribus A.A.,Drijfhout S.S.,Dijkstra H.A.. Meridional overturning circulation: Stability and ocean feedbacks in a box model[J]. Climate Dynamics,2014-01-01,42(2017-01-02)