DOI: 10.1002/jgrd.50390
论文题名: What is the effect of unresolved internal climate variability on climate sensitivity estimates?
作者: Olson R. ; Sriver R. ; Chang W. ; Haran M. ; Urban N.M. ; Keller K.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 10 起始页码: 4348
结束页码: 4358
语种: 英语
英文关键词: climate sensitivity
; Gaussian process
; internal climate variability
; uncertainty
Scopus关键词: Carbon dioxide
; Climate change
; Climate sensitivity
; Estimation uncertainties
; Gaussian Processes
; Historical observation
; Intermediate complexity
; Internal climate variability
; Parameter estimation method
; uncertainty
; Estimation
; climate variation
; estimation method
; sensitivity analysis
; simulation
英文摘要: Many studies have attempted to estimate the equilibrium climate sensitivity (CS) to the doubling of CO2 concentrations. One common methodology is to compare versions of Earth models of intermediate complexity (EMICs) to spatially and/or temporally averaged historical observations. Despite the persistent efforts, CS remains uncertain. It is, thus far, unclear what is driving this uncertainty. Moreover, the effects of the internal climate variability on the CS estimates obtained using this method have not received thorough attention in the literature. Using a statistical approximator ("emulator") of an EMIC, we show in an observation system simulation study that unresolved internal climate variability appears to be a key driver of CS uncertainty (as measured by the 68% credible interval). We first simulate many realizations of pseudo-observations from an emulator at a "true" prescribed CS, and then reestimate the CS using the pseudo-observations and an inverse parameter estimation method. We demonstrate that a single realization of the internal variability can result in a sizable discrepancy between the best CS estimate and the truth. Specifically, the average discrepancy is 0.84°C, with the feasible range up to several °C. The results open the possibility that recent climate sensitivity estimates from global observations and EMICs are systematically considerably lower or higher than the truth, since they are typically based on the same realization of climate variability. This possibility should be investigated in future work. We also find that estimation uncertainties increase at higher climate sensitivities, suggesting that a high CS might be difficult to detect. Key pointsInternal climate variability is a key driver of climate sensitivity uncertaintyHigh climate sensitivities are especially difficult to estimate ©2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63713
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Geosciences, Penn State University, University Park PA, United States; Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana IL, United States; Department of Statistics, Penn State University, University Park PA, United States; Computational Physics and Methods (CCS-2), Los Alamos National Laboratory, Los Alamos NM, United States; Earth and Environmental Systems Institute, Penn State University, University Park PA, United States
Recommended Citation:
Olson R.,Sriver R.,Chang W.,et al. What is the effect of unresolved internal climate variability on climate sensitivity estimates?[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(10)