气候变化领域集成服务门户(CCPortal): Contributions of atmospheric stochastic forcing and intrinsic ocean modes to North Atlantic ocean interdecadal variability

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DOI	10.1175/JCLI-D-19-0522.1
	Contributions of atmospheric stochastic forcing and intrinsic ocean modes to North Atlantic ocean interdecadal variability
	Arzel O.; Huck T.
发表日期	2020
ISSN	0894-8755
起始页码	2351
结束页码	2370
卷号	33 期号:6
英文摘要	Atmospheric stochastic forcing associated with the North Atlantic Oscillation (NAO) and intrinsic ocean modes associated with the large-scale baroclinic instability of the North Atlantic Current (NAC) are recognized as two strong paradigms for the existence of the Atlantic multidecadal oscillation (AMO). The degree to which each of these factors contribute to the low-frequency variability of the North Atlantic is the central question in this paper. This issue is addressed here using an ocean general circulation model run under a wide range of background conditions extending from a supercritical regime where the oceanic variability spontaneously develops in the absence of any atmospheric noise forcing to a damped regime where the variability requires some noise to appear. The answer to the question is captured by a single dimensionless number G measuring the ratio between the oceanic and atmospheric contributions, as inferred from the buoyancy variance budget of the western subpolar region. Using this diagnostic, about two-thirds of the sea surface temperature (SST) variance in the damped regime is shown to originate from atmospheric stochastic forcing whereas heat content is dominated by internal ocean dynamics. Stochastic wind stress forcing is shown to substantially increase the role played by damped ocean modes in the variability. The thermal structure of the variability is shown to differ fundamentally between the supercritical and damped regimes, with abrupt modifications around the transition between the two regimes. Ocean circulation changes are further shown to be unimportant for setting the pattern of SST variability in the damped regime but are fundamental for a preferred time scale to emerge. © 2020 American Meteorological Society.
英文关键词	Atmospheric pressure; Budget control; Stochastic systems; Surface waters; Atlantic multidecadal oscillations; Atmospheric contributions; Inter-decadal variability; Low frequency variability; North Atlantic Currents; North Atlantic oscillations; Ocean general circulation models; Sea surface temperature (SST); Oceanography
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171396
作者单位	Laboratoire d’Océanographie Physique et Spatiale, University of Brest, CNRS, IRD, IFREMER, Brest, France
推荐引用方式 GB/T 7714	Arzel O.,Huck T.. Contributions of atmospheric stochastic forcing and intrinsic ocean modes to North Atlantic ocean interdecadal variability[J],2020,33(6).
APA	Arzel O.,&Huck T..(2020).Contributions of atmospheric stochastic forcing and intrinsic ocean modes to North Atlantic ocean interdecadal variability.Journal of Climate,33(6).
MLA	Arzel O.,et al."Contributions of atmospheric stochastic forcing and intrinsic ocean modes to North Atlantic ocean interdecadal variability".Journal of Climate 33.6(2020).