DOI: 10.1175/JCLI-D-12-00199.1
Scopus记录号: 2-s2.0-84878966772
论文题名: Model bias reduction and the limits of oceanic decadal predictability: Importance of the deep ocean
作者: Sévellec F. ; Fedorov A.V.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2013
卷: 26, 期: 11 起始页码: 3688
结束页码: 3707
语种: 英语
Scopus关键词: Climate prediction
; Decadal predictions
; Decadal timescale
; Initial conditions
; Initial perturbation
; Meridional temperature gradient
; Ocean general circulation models
; Temperature anomaly
; Climatology
; Errors
; Salinity measurement
; Oceanography
; air-sea interaction
; climate modeling
; climate prediction
; decadal variation
; deep sea
; error analysis
; oceanic general circulation model
; perturbation
; salinity
; standing wave
; temperature anomaly
; temperature gradient
; upper ocean
; water temperature
; Southern Ocean
英文摘要: Ocean general circulation models (GCMs), as part of comprehensive climate models, are extensively used for experimental decadal climate prediction. Understanding the limits of decadal ocean predictability is critical for making progress in these efforts. However, when forced with observed fields at the surface, ocean models develop biases in temperatureand salinity. Here, the authors ask two complementary questions related to both decadal prediction and model bias: 1) Can the bias be temporarily reduced and the prediction improved by perturbing the initial conditions? 2) How fast will such initial perturbations grow? To answer these questions, the authors use a realistic ocean GCM and compute temperature and salinity perturbations that reduce the model bias most efficiently during a given time interval. The authors find that to reduce this bias, especially pronounced in the upper ocean above 1000 m, initial perturbations should be imposed inthe deep ocean (specifically, in the Southern Ocean). Over 14 yr, a 0.1-K perturbation in the deep ocean can induce a temperature anomaly of several kelvins in the upper ocean, partially reducing the bias.Acorollary of these results is thatsmall initialization errors in the deep ocean can produce large errors in the upper-ocean temperature on decadal time scales, which can be interpreted as a decadal predictability barrier associated with ocean dynamics. To study the mechanisms of the perturbation growth, the authors formulate an idealized model describing temperature anomalies in the SouthernOcean. The results indicate that the strong mean meridional temperature gradient in this region enhances the sensitivityof the upper ocean to deep-ocean perturbations through nonnormal dynamics generating pronounced stationary-wave patterns. © 2013 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51863
Appears in Collections: 气候变化事实与影响
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作者单位: Ocean and Earth Science, National Oceanographic Centre Southampton, University of Southampton, Waterfront campus, European Way, Southampton, United Kingdom; Department of Geology and Geophysics, Yale University, New Haven, CT, United States
Recommended Citation:
Sévellec F.,Fedorov A.V.. Model bias reduction and the limits of oceanic decadal predictability: Importance of the deep ocean[J]. Journal of Climate,2013-01-01,26(11)