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DOI	10.1175/JCLI-D-19-0964.1
	A linear inverse model of tropical and south pacific climate variability: Optimal structure and stochastic forcing
	Lou J.; O'Kane T.J.; Holbrook N.J.
发表日期	2021
ISSN	0894-8755
起始页码	143
结束页码	155
卷号	34 期号:1
英文摘要	A stochastically forced linear inverse model (LIM) of the combined modes of variability from the tropical and South Pacific Oceans is used to investigate the linear growth of optimal initial perturbations and to identify the spatiotemporal features of the stochastic forcing associated with the atmospheric Pacific-South American patterns 1 and 2 (PSA1 and PSA2). Optimal initial perturbations are shown to project onto El Niño-Southern Oscillation (ENSO) and South Pacific decadal oscillation (SPDO), where the inclusion of subsurface South Pacific Ocean temperature variability significantly increases the multiyear linear predictability of the deterministic system. We show that the optimal extratropical sea surface temperature (SST) precursor is associated with the South Pacific meridional mode, which takes from 7 to 9 months to linearly evolve into the final ENSO and SPDO peaks in both the observations and as simulated in an atmosphere-forced ocean model. The optimal subsurface precursor resembles its peak phase, but with a weak amplitude, representing oceanic Rossby waves in the extratropical South Pacific. The stochastic forcing is estimated as the residual by removing the deterministic dynamics from the actual tendency under a centered difference approximation. The resulting stochastic forcing time series satisfies the Gaussian white noise assumption of the LIM. We show that the PSA-like variability is strongly associated with stochastic SST forcing in the tropical and South Pacific Oceans and contributes not only to excite the optimal initial perturbations associated with ENSO and the SPDO but in general to activate the entire stochastic SST forcing, especially in austral summer. © 2020 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Atmospheric pressure; Climate models; Climatology; Mechanical waves; Ocean currents; Stochastic models; Structural optimization; Surface waters; Tropics; White noise; Deterministic systems; Difference approximation; Linear inverse models; Pacific decadal oscillation; Sea surface temperature (SST); South pacific oceans; Southern oscillation; Spatio temporal features; Stochastic systems; climate prediction; climate variation; El Nino-Southern Oscillation; inverse analysis; numerical model; Pacific Decadal Oscillation; Rossby wave; sea surface temperature; spatiotemporal analysis; stochasticity; Pacific Ocean; Pacific Ocean (South); Pacific Ocean (Tropical)
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170985
作者单位	Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia; ARC Centre of Excellence for Climate System Science, University of Tasmania, Hobart, TAS, Australia; CSIRO Oceans and Atmosphere, Hobart, TAS, Australia; ARC Centre of Excellence for Climate Extremes, University of Tasmania, Hobart, TAS, Australia
推荐引用方式 GB/T 7714	Lou J.,O'Kane T.J.,Holbrook N.J.. A linear inverse model of tropical and south pacific climate variability: Optimal structure and stochastic forcing[J],2021,34(1).
APA	Lou J.,O'Kane T.J.,&Holbrook N.J..(2021).A linear inverse model of tropical and south pacific climate variability: Optimal structure and stochastic forcing.Journal of Climate,34(1).
MLA	Lou J.,et al."A linear inverse model of tropical and south pacific climate variability: Optimal structure and stochastic forcing".Journal of Climate 34.1(2021).