气候变化领域集成服务门户(CCPortal): Observable; low-order dynamical controls on thresholds of the Atlantic meridional overturning circulation

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DOI	10.1007/s00382-019-04956-1
	Observable; low-order dynamical controls on thresholds of the Atlantic meridional overturning circulation
	Wood R.A.; Rodríguez J.M.; Smith R.S.; Jackson L.C.; Hawkins E.
发表日期	2019
ISSN	0930-7575
起始页码	6815
结束页码	6834
卷号	53 期号:11
英文摘要	We examine the dynamics of thresholds of the Atlantic Meridional Overturning Circulation (AMOC) in an Atmosphere–Ocean General Circulation Model (AOGCM) and a simple box model. We show that AMOC thresholds in the AOGCM are controlled by low-order dynamics encapsulated in the box model. In both models, AMOC collapse is primarily initiated by the development of a strong salinity advection feedback in the North Atlantic. The box model parameters are potentially observable properties of the unperturbed (present day) ocean state, and when calibrated to a range of AOGCM states predict (within some error bars) the critical rate of fresh water input (Hcrit) needed to turn off the AMOC in the AOGCM. In contrast, the meridional fresh water transport by the MOC (MOV, a widely-used diagnostic of AMOC bi-stability) on its own is a poor predictor of Hcrit. When the AOGCM is run with increased atmospheric carbon dioxide, Hcrit increases. We use the dynamical understanding from the box model to show that this increase is due partly to intensification of the global hydrological cycle and heat penetration into the near-surface ocean, both robust features of climate change projections. However changes in the gyre fresh water transport efficiency (a less robustly modelled process) are also important. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Atlantic meridional overturning circulation; Climate change; Dynamics; Fresh water; Thresholds
语种	英语
scopus关键词	atmospheric general circulation model; climate change; freshwater; gyre; meridional circulation; oceanic general circulation model; overturn; threshold; Atlantic Ocean; Atlantic Ocean (North)
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/145798
作者单位	Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, United Kingdom; National Centre for Atmospheric Science, University of Reading, Whiteknights, Reading, RG6 7BE, United Kingdom
推荐引用方式 GB/T 7714	Wood R.A.,Rodríguez J.M.,Smith R.S.,et al. Observable; low-order dynamical controls on thresholds of the Atlantic meridional overturning circulation[J],2019,53(11).
APA	Wood R.A.,Rodríguez J.M.,Smith R.S.,Jackson L.C.,&Hawkins E..(2019).Observable; low-order dynamical controls on thresholds of the Atlantic meridional overturning circulation.Climate Dynamics,53(11).
MLA	Wood R.A.,et al."Observable; low-order dynamical controls on thresholds of the Atlantic meridional overturning circulation".Climate Dynamics 53.11(2019).