气候变化领域集成服务门户(CCPortal): Influence of Westerly Wind Events stochasticity on El Niño amplitude: the case of 2014 vs. 2015

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DOI	10.1007/s00382-017-3938-9
	Influence of Westerly Wind Events stochasticity on El Niño amplitude: the case of 2014 vs. 2015
	Puy M.; Vialard J.; Lengaigne M.; Guilyardi E.; DiNezio P.N.; Voldoire A.; Balmaseda M.; Madec G.; Menkes C.; Mcphaden M.J.
发表日期	2019
ISSN	0930-7575
起始页码	7435
结束页码	7454
卷号	52 期号:12
英文摘要	The weak El Niño of 2014 was preceded by anomalously high equatorial Pacific Warm Water Volume (WWV) and strong Westerly Wind Events (WWEs), which typically lead to record breaking El Nino, like in 1997 and 2015. Here, we use the CNRM–CM5 coupled model to investigate the causes for the stalled El Niño in 2014 and the necessary conditions for extreme El Niños. This model is ideally suited to study this problem because it simulates all the processes thought to be critical for the onset and development of El Niño. It captures El Niño preconditioning by WWV, the WWEs characteristics and their deterministic behaviour in response to warm pool displacements. Our main finding is, that despite their deterministic control, WWEs display a sufficiently strong stochastic component to explain the distinct evolutions of El Niño in 2014 and 2015. A 100-member ensemble simulation initialized with early-spring equatorial conditions analogous to those observed in 2014 and 2015 demonstrates that early-year elevated WWV and strong WWEs preclude the occurrence of a La Niña but lead to El Niños that span the weak (with few WWEs) to extreme (with many WWEs) range. Sensitivity experiments confirm that numerous/strong WWEs shift the El Niño distribution toward larger amplitudes, with a particular emphasis on summer/fall WWEs occurrence which result in a five-fold increase of the odds for an extreme El Niño. A long simulation further demonstrates that sustained WWEs throughout the year and anomalously high WWV are necessary conditions for extreme El Niño to develop. In contrast, we find no systematic influence of easterly wind events (EWEs) on the El Niño amplitude in our model. Our results demonstrate that the weak amplitude of El Niño in 2014 can be explained by WWEs stochastic variations without invoking EWEs or remote influences from outside the tropical Pacific and therefore its peak amplitude was inherently unpredictable at long lead-time. © 2017, Springer-Verlag GmbH Germany.
英文关键词	Easterly wind events; El Niño; El Niño predictors; Extreme El Niño events; Predictability; Westerly Wind Events
语种	英语
scopus关键词	El Nino; extreme event; prediction; stochasticity; warm pool; westerly
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/146279
作者单位	LOCEAN/IPSL, Sorbonne Universités/UPMC-CNRS-IRD-MNHN, Paris, France; Indo-French Cell for Water Sciences, IISc-NIO-IITM-IRD Joint International Laboratory, NIO, Goa, India; NCAS-Climate, University of Reading, Reading, United Kingdom; Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, J. J. Pickle Research Campus, Building 196 10100 Burnet Road (R2200), Austin, TX, United States; CNRM, Météo France/UMR 3589, Toulouse, France; European Centre of Medium Range Weather Forecasts, Reading, United Kingdom; Centre IRD, Nouméa, New Caledonia; NOAA PMEL, Seattle, WA, United States
推荐引用方式 GB/T 7714	Puy M.,Vialard J.,Lengaigne M.,et al. Influence of Westerly Wind Events stochasticity on El Niño amplitude: the case of 2014 vs. 2015[J],2019,52(12).
APA	Puy M..,Vialard J..,Lengaigne M..,Guilyardi E..,DiNezio P.N..,...&Mcphaden M.J..(2019).Influence of Westerly Wind Events stochasticity on El Niño amplitude: the case of 2014 vs. 2015.Climate Dynamics,52(12).
MLA	Puy M.,et al."Influence of Westerly Wind Events stochasticity on El Niño amplitude: the case of 2014 vs. 2015".Climate Dynamics 52.12(2019).