气候变化领域集成服务门户(CCPortal): Optimally growing initial errors of El Niño events in the CESM

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DOI	10.1007/s00382-021-05668-1
	Optimally growing initial errors of El Niño events in the CESM
	Xu H.; Chen L.; Duan W.
发表日期	2021
ISSN	0930-7575
起始页码	1227
结束页码	1249
卷号	56 期号:2021-11-12
英文摘要	The optimally growing initial errors (OGEs) of El Niño events are found in the Community Earth System Model (CESM) by the conditional nonlinear optimal perturbation (CNOP) method. Based on the characteristics of low-dimensional attractors for ENSO (El Niño Southern Oscillation) systems, we apply singular vector decomposition (SVD) to reduce the dimensions of optimization problems and calculate the CNOP in a truncated phase space by the differential evolution (DE) algorithm. In the CESM, we obtain three types of OGEs of El Niño events with different intensities and diversities and call them type-1, type-2 and type-3 initial errors. Among them, the type-1 initial error is characterized by negative SSTA errors in the equatorial Pacific accompanied by a negative west–east slope of subsurface temperature from the subsurface to the surface in the equatorial central-eastern Pacific. The type-2 initial error is similar to the type-1 initial error but with the opposite sign. The type-3 initial error behaves as a basin-wide dipolar pattern of tropical sea temperature errors from the sea surface to the subsurface, with positive errors in the upper layers of the equatorial eastern Pacific and negative errors in the lower layers of the equatorial western Pacific. For the type-1 (type-2) initial error, the negative (positive) temperature errors in the eastern equatorial Pacific develop locally into a mature La Niña (El Niño)-like mode. For the type-3 initial error, the negative errors in the lower layers of the western equatorial Pacific propagate eastward with Kelvin waves and are intensified in the eastern equatorial Pacific. Although the type-1 and type-3 initial errors have different spatial patterns and dynamic growing mechanisms, both cause El Niño events to be underpredicted as neutral states or La Niña events. However, the type-2 initial error makes a moderate El Niño event to be predicted as an extremely strong event. © 2021, The Author(s).
英文关键词	CESM; Conditional nonlinear optimal perturbation; ENSO predictability; Optimally growing initial error; Optimization calculation
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/183263
作者单位	State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China; Shanghai Central Meteorological Observatory, Shanghai, 200030, China
推荐引用方式 GB/T 7714	Xu H.,Chen L.,Duan W.. Optimally growing initial errors of El Niño events in the CESM[J],2021,56(2021-11-12).
APA	Xu H.,Chen L.,&Duan W..(2021).Optimally growing initial errors of El Niño events in the CESM.Climate Dynamics,56(2021-11-12).
MLA	Xu H.,et al."Optimally growing initial errors of El Niño events in the CESM".Climate Dynamics 56.2021-11-12(2021).