DOI: 10.1007/s00382-011-1117-y
Scopus记录号: 2-s2.0-84862987113
论文题名: Abrupt millennial variability and interdecadal-interstadial oscillations in a global coupled model: Sensitivity to the background climate state
作者: Arzel O. ; England M.H. ; de Verdière A.C. ; Huck T.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2012
卷: 39, 期: 2017-01-02 起始页码: 259
结束页码: 275
语种: 英语
英文关键词: Atlantic meridional overturning circulation
; Dansgaard-Oeschger events
; Millennial and interdecadal variability
; paleoclimate
英文摘要: The origin and bifurcation structure of abrupt millennial-scale climate transitions under steady external solar forcing and in the absence of atmospheric synoptic variability is studied by means of a global coupled model of intermediate complexity. We show that the origin of Dansgaard-Oeschger type oscillations in the model is caused by the weaker northward oceanic heat transport in the Atlantic basin. This is in agreement with previous studies realized with much simpler models, based on highly idealized geometries and simplified physics. The existence of abrupt millennial-scale climate transitions during glacial times can therefore be interpreted as a consequence of the weakening of the negative temperature-advection feedback. This is confirmed through a series of numerical experiments designed to explore the sensitivity of the bifurcation structure of the Atlantic meridional overturning circulation to increased atmospheric CO2 levels under glacial boundary conditions. Contrasting with the cold, stadial, phases of millennial oscillations, we also show the emergence of strong interdecadal variability in the North Atlantic sector during warm interstadials. The instability driving these interdecadal-interstadial oscillations is shown to be identical to that found in ocean-only models forced by fixed surface buoyancy fluxes, that is, a large-scale baroclinic instability developing in the vicinity of the western boundary current in the North Atlantic. Comparisons with modern observations further suggest a physical mechanism similar to that driving the 30-40 years time scale associated with the Atlantic multidecadal oscillation. © 2011 Springer-Verlag. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/55202
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), The University of New South Wales, Sydney, Australia; Laboratoire de Physique des Océans (LPO), Université de Bretagne Occidentale, Brest, France
Recommended Citation:
Arzel O.,England M.H.,de Verdière A.C.,et al. Abrupt millennial variability and interdecadal-interstadial oscillations in a global coupled model: Sensitivity to the background climate state[J]. Climate Dynamics,2012-01-01,39(2017-01-02)