DOI: 10.1007/s00382-016-3290-5
Scopus记录号: 2-s2.0-84980025241
论文题名: Drivers of coupled model ENSO error dynamics and the spring predictability barrier
作者: Larson S.M. ; Kirtman B.P.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2017
卷: 48, 期: 2017-11-12 起始页码: 3631
结束页码: 3644
语种: 英语
英文关键词: ENSO
; ENSO predictability
; Error dynamics
; Forecast errors
; Spring predictability barrier
英文摘要: Despite recent improvements in ENSO simulations, ENSO predictions ultimately remain limited by error growth and model inadequacies. Determining the accompanying dynamical processes that drive the growth of certain types of errors may help the community better recognize which error sources provide an intrinsic limit to predictability. This study applies a dynamical analysis to previously developed CCSM4 error ensemble experiments that have been used to model noise-driven error growth. Analysis reveals that ENSO-independent error growth is instigated via a coupled instability mechanism. Daily error fields indicate that persistent stochastic zonal wind stress perturbations (τx′) near the equatorial dateline activate the coupled instability, first driving local SST and anomalous zonal current changes that then induce upwelling anomalies and a clear thermocline response. In particular, March presents a window of opportunity for stochastic τx′ to impose a lasting influence on the evolution of eastern Pacific SST through December, suggesting that stochastic τx′ is an important contributor to the spring predictability barrier. Stochastic winds occurring in other months only temporarily affect eastern Pacific SST for 2–3 months. Comparison of a control simulation with an ENSO cycle and the ENSO-independent error ensemble experiments reveals that once the instability is initiated, the subsequent error growth is modulated via an ENSO-like mechanism, namely the seasonal strength of the Bjerknes feedback. Furthermore, unlike ENSO events that exhibit growth through the fall, the growth of ENSO-independent SST errors terminates once the seasonal strength of the Bjerknes feedback weakens in fall. Results imply that the heat content supplied by the subsurface precursor preceding the onset of an ENSO event is paramount to maintaining the growth of the instability (or event) through fall. © 2016, Springer-Verlag Berlin Heidelberg. 资助项目: NSF, National Science Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53201
Appears in Collections: 过去全球变化的重建
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作者单位: Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL, United States
Recommended Citation:
Larson S.M.,Kirtman B.P.. Drivers of coupled model ENSO error dynamics and the spring predictability barrier[J]. Climate Dynamics,2017-01-01,48(2017-11-12)