气候变化领域集成服务门户(CCPortal): El Niño phase-dependent high-frequency variability in Western Equatorial Pacific

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DOI	10.1007/s00382-020-05376-2
	El Niño phase-dependent high-frequency variability in Western Equatorial Pacific
	Sun M.; Li T.; Chen L.
发表日期	2020
ISSN	0930-7575
起始页码	2165
结束页码	2184
卷号	55
英文摘要	The intensities of high-frequency (HF) variability with period less than 90 days at different phases of El Niño events were investigated through observational data analysis. A large asymmetry in the HF variability intensity between the developing phase and decaying phase (i.e., pre-peak stage versus post-peak stage) of eastern Pacific (EP) El Niño is revealed, while the amplitude and spatial pattern of the sea surface temperature anomaly during these two stages are almost same. The diagnosis shows that the asymmetry is significant not only on intraseasonal time scale (20–90 days) but also on synoptic time scale (less than 20 days). The anatomy analysis further unveils that the asymmetric synoptic variability between the two episodes arises from the asymmetric intensities of the equatorial Rossby and mixed Rossby gravity (MRG) waves. We suggest that the stronger vertical easterly wind shear in the pre-peak stage than that in the post-peak stage plays a vital role in causing the stronger synoptic equatorial Rossby and MRG waves in the pre-peak stage. Meanwhile, the drier atmosphere and more descending motion in the post-peak stage contribute to the weakened intraseasonal and synoptic variabilities in that stage. The aforementioned weakened easterly wind shear, drier atmosphere and more descending motion in the post-peak stage can be traced back to the occurrence of the anomalous anticyclone circulation over the western North Pacific since the decaying phase of El Niño. The essential role of large-scale environmental conditions in modulating the HF variability during the two episodes is further confirmed by modeling experiments. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Asymmetric high-frequency variability; El Niño; Vertical wind shear; Western North Pacific anticyclone
语种	英语
scopus关键词	anticyclone; El Nino; Rossby wave; sea surface temperature; seasonal variation; synoptic meteorology; wind shear; Pacific Ocean; Pacific Ocean (Equatorial)
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/145309
作者单位	Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environmental Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing, China; International Pacific Research Center and Department of Atmospheric Sciences, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, Honolulu, HI 96822, United States; 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; State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Hangzhou, China
推荐引用方式 GB/T 7714	Sun M.,Li T.,Chen L.. El Niño phase-dependent high-frequency variability in Western Equatorial Pacific[J],2020,55.
APA	Sun M.,Li T.,&Chen L..(2020).El Niño phase-dependent high-frequency variability in Western Equatorial Pacific.Climate Dynamics,55.
MLA	Sun M.,et al."El Niño phase-dependent high-frequency variability in Western Equatorial Pacific".Climate Dynamics 55(2020).