气候变化领域集成服务门户(CCPortal): Breakdown of NAO reproducibility into internal versus externally-forced components: a two-tier pilot study

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DOI	10.1007/s00382-018-4141-3
	Breakdown of NAO reproducibility into internal versus externally-forced components: a two-tier pilot study
	Douville H.; Ribes A.; Tyteca S.
发表日期	2019
ISSN	0930-7575
起始页码	29
结束页码	48
卷号	52 期号:2020-01-02
英文摘要	Assessing the ability of atmospheric models to capture observed climate variations when driven by observed sea surface temperature (SST), sea ice concentration (SIC) and radiative forcings is a prerequisite for the feasibility of near term climate predictions. Here we achieve ensembles of global atmospheric simulations to assess and attribute the reproducibility of the boreal winter atmospheric circulation against the European Centre for Medium Range Forecasts (ECMWF) twentieth century reanalysis (ERA20C). Our control experiment is driven by the observed SST/SIC from the Atmospheric Model Intercomparison Project. It is compared to a similar ensemble performed with the ECMWF model as a first step toward ERA20C. Moreover, a two-tier methodology is used to disentangle externally-forced versus internal variations in the observed SST/SIC boundary conditions and run additional ensembles allowing us to attribute the observed atmospheric variability. The focus is mainly on the North Atlantic Oscillation (NAO) variability which is more reproducible in our model than in the ECMWF model. This result is partly due to the simulation of a positive NAO trend across the full 1920–2014 integration period. In line with former studies, this trend might be mediated by a circumglobal teleconnection mechanism triggered by increasing precipitation over the tropical Indian Ocean (TIO). Surprisingly, this response is mainly related to the internal SST variability and is not found in the ECMWF model driven by an alternative SST dataset showing a weaker TIO warming in the first half of the twentieth century. Our results may reconcile the twentieth century observations with the twenty-first century projections of the NAO. They should be however considered with caution given the limited size of our ensembles, the possible influence of other sources of NAO variability, and the uncertainties in the tropical SST trend and breakdown between internal versus externally-forced variability. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Attribution; Multidecadal variability; North Atlantic oscillation; Reproducibility
语种	英语
scopus关键词	atmospheric circulation; atmospheric modeling; climate variation; decadal variation; ensemble forecasting; North Atlantic Oscillation; radiative forcing; sea ice; sea surface temperature; Europe
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/146592
作者单位	Météo-France/CNRM, CNRM/GMGEC/AMACS, 42 Avenue Coriolis, Toulouse Cedex 01, 31057, France
推荐引用方式 GB/T 7714	Douville H.,Ribes A.,Tyteca S.. Breakdown of NAO reproducibility into internal versus externally-forced components: a two-tier pilot study[J],2019,52(2020-01-02).
APA	Douville H.,Ribes A.,&Tyteca S..(2019).Breakdown of NAO reproducibility into internal versus externally-forced components: a two-tier pilot study.Climate Dynamics,52(2020-01-02).
MLA	Douville H.,et al."Breakdown of NAO reproducibility into internal versus externally-forced components: a two-tier pilot study".Climate Dynamics 52.2020-01-02(2019).