DOI: 10.1175/JCLI-D-18-0243.1
Scopus记录号: 2-s2.0-85054066930
论文题名: On the dynamical mechanisms governing El Niño-Southern oscillation irregularity
作者: Berner J. ; Sardeshmukh P.D. ; Christensen H.M.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 20 起始页码: 8401
结束页码: 8419
语种: 英语
英文关键词: ENSO
; Interannual variability
; Model errors
; Oscillations
; Stochastic models
; Tropical variability
Scopus关键词: Atmospheric pressure
; Climate models
; Climatology
; Oceanography
; Parameterization
; Stochastic control systems
; Stochastic systems
; Surface waters
; Tropics
; ENSO
; Interannual variability
; Model errors
; Oscillations
; Tropical variability
; Stochastic models
英文摘要: This study investigates the mechanisms by which short time-scale perturbations to atmospheric processes can affect El Niño-Southern Oscillation (ENSO) in climate models. To this end a control simulation of NCAR's Community Climate System Model is compared to a simulation in which the model's atmospheric diabatic tendencies are perturbed every time step using a Stochastically Perturbed Parameterized Tendencies (SPPT) scheme. The SPPT simulation compares better with ECMWF's twentieth-century reanalysis in having lower interannual sea surface temperature (SST) variability and more irregular transitions between El Niño and La Niña states, as expressed by a broader, less peaked spectrum. Reduced-order linear inverse models (LIMs) derived from the 1-month lag covariances of selected tropical variables yield good representations of tropical interannual variability in the two simulations. In particular, the basic features of ENSO are captured by the LIM's least damped oscillatory eigenmode. SPPT reduces the damping time scale of this eigenmode from 17 to 11 months, which is in better agreement with the 8 months obtained from reanalyses. This noise-induced stabilization is consistent with perturbations to the frequency of the ENSO eigenmode and explains the broadening of the SST spectrum (i.e., the greater ENSO irregularity). Although the improvement in ENSO shown here was achieved through stochastic physics parameterizations, it is possible that similar improvements could be realized through changes in deterministic parameterizations or higher numerical resolution. It is suggested that LIMs could provide useful insight into model sensitivities, uncertainties, and biases also in those cases. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110682
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: National Center for Atmospheric Research, Boulder, CO, United States; Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States
Recommended Citation:
Berner J.,Sardeshmukh P.D.,Christensen H.M.. On the dynamical mechanisms governing El Niño-Southern oscillation irregularity[J]. Journal of Climate,2018-01-01,31(20)