DOI: 10.1007/s00382-014-2391-2
Scopus记录号: 2-s2.0-84940721421
论文题名: Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal
作者: Sgubin G. ; Swingedouw D. ; Drijfhout S. ; Hagemann S. ; Robertson E.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2015
卷: 45, 期: 2017-05-06 起始页码: 1429
结束页码: 1450
语种: 英语
英文关键词: AMOC stability
; Atlantic meridional overturning circulation
; Climate modelling
; Global warming
; Reversibility
; Salt advection feedback
英文摘要: The response of the Atlantic meridional overturning circulation (AMOC) to an increase of radiative forcing (ramp-up) and a subsequent reversal of radiative forcing (ramp-down) is analyzed for four different global climate models. Due to changes in ocean temperature and hydrological cycle, all models show a weakening of the AMOC during the ramp-up phase. Once the external forcing is reversed, the results become model dependent. For IPSL-CM5A-LR, the AMOC continues its weakening trend for most of the ramp-down experiment. For HadGEM2-ES, the AMOC trend reverses once the external forcing also reverses, without recovering its initial value. For EC-EARTH and MPI-ESM-LR the recovery is anomalously strong yielding an AMOC overshoot. A robust linear dependency can be established between AMOC and density difference between North Atlantic (NA) deep water formation region and South Atlantic (SA). In particular, AMOC evolution is primarily controlled by a meridional salinity contrast between these regions. During the warming scenario, the subtropical Atlantic becomes saltier while the NA experiences a net freshening which favours an AMOC weakening. The different behaviour in the models during the ramp-down is dependent on the response of the ocean at the boundaries of NA and SA. The way in which the positive salinity anomaly stored in the subtropical Atlantic during the ramp-up is subsequently released elsewhere, characterizes the recovery. An out-of-phase response of the salinity transport at $$48^{\circ }\hbox {N}$$48∘N and $$34^{\circ }\hbox {S}$$34∘S boundaries is able to control the meridional density contrast between NA and SA during the transient experiments. Such a non-synchronized response is mainly controlled by changes in gyre salinity transport rather than by changes in overturning transport, thus suggesting a small role of the salt advection feedback in the evolution of the AMOC. © 2014, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54020
Appears in Collections: 过去全球变化的重建
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作者单位: Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Bordeaux, France; Institut Pierre Simon Laplace (IPSL), Paris, France; Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands; Max Planck Institute for Meteorology (MPI-M), Hamburg, Germany; Met Office Hadley Centre, Exeter, United Kingdom
Recommended Citation:
Sgubin G.,Swingedouw D.,Drijfhout S.,et al. Multimodel analysis on the response of the AMOC under an increase of radiative forcing and its symmetrical reversal[J]. Climate Dynamics,2015-01-01,45(2017-05-06)