DOI: 10.1175/JCLI-D-14-00033.1
Scopus记录号: 2-s2.0-84907587718
论文题名: Nonlinear controls on the persistence of La Niña
作者: DiNezio P.N. ; Deser C.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2014
卷: 27, 期: 19 起始页码: 7335
结束页码: 7355
语种: 英语
Scopus关键词: ENSO
; La nina
; Model evaluation/performance
; Non-linear model
; Tropical variability
; Climate models
; climate modeling
; climate variation
; computer simulation
; El Nino-Southern Oscillation
; heat budget
; La Nina
; nonlinearity
; sea surface temperature
; seasonality
; temperature anomaly
; thermocline
英文摘要: A large fraction (35%-50%) of observed La Niña events last two years or longer, in contrast to the great majority of ElNiño events,which last one year.Here, the authors explore the nonlinear processes responsible for the multiyear persistence of La Niña in the Community Climate System Model, version 4 (CCSM4), a coupled climate model that simulates the asymmetric duration of La Niña and El Niño events realistically. The authors develop a nonlinear delayed-oscillator (NDO) model of the El Niño-Southern Oscillation (ENSO) to explore the mechanisms governing the duration of La Niña. The NDO includes nonlinear and seasonally dependent feedbacks derived from the CCSM4 heat budget, which allow it to simulate key ENSO features in quantitative agreement with CCSM4. Sensitivity experiments with theNDOshow that the nonlinearity in the delayed thermocline feedback is the sole process controlling the duration of La Niña events. The authors' results show that, as La Niña events become stronger, the delayed thermocline response does not increase proportionally. This nonlinearity arises from two processes: 1) the response of winds to sea surface temperature anomalies and 2) the ability of thermocline depth anomalies to influence temperatures at the base of the mixed layer. Thus, strong La Niña events require that the thermocline remains deeper for longer than 1 yr for sea surface temperatures to return to neutral. Ocean reanalysis data show evidence for this thermocline nonlinearity, suggesting that this process could be at work in nature. © 2014 American Meteorological Society. 资助项目: NOAA, National Oceanic and Atmospheric Administration
; NASA, National Oceanic and Atmospheric Administration
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51348
Appears in Collections: 气候变化事实与影响
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作者单位: International Pacific Research Center, School of Ocean and Earth Science and Technology, University of Hawai'i at Manoa, Honolulu, HI, United States; National Center for Atmospheric Research, Boulder, CO, United States
Recommended Citation:
DiNezio P.N.,Deser C.. Nonlinear controls on the persistence of La Niña[J]. Journal of Climate,2014-01-01,27(19)