DOI: 10.1007/s00382-014-2206-5
Scopus记录号: 2-s2.0-84939897858
论文题名: Global instability in the Ghil–Sellers model
作者: Bódai T. ; Lucarini V. ; Lunkeit F. ; Boschi R.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2015
卷: 44, 期: 2017-11-12 起始页码: 3361
结束页码: 3381
语种: 英语
英文关键词: Edge tracking
; Energy balance model
; Global instability
; Nonequilibrium thermodynamics
; Tipping point
英文摘要: The Ghil–Sellers model, a diffusive one-dimensional energy balance model of Earth’s climate, features—for a considerable range of the parameter descriptive of the intensity of the incoming radiation—two stable climate states, where the bistability results from the celebrated ice-albedo feedback. The warm state is qualitatively similar to the present climate, while the cold state corresponds to snowball conditions. Additionally, in the region of bistability, one can find unstable climate states. We find such unstable states by applying for the first time in a geophysical context the so-called edge tracking method, which has been used for studying multiple coexisting states in shear flows. This method has a great potential for studying the global instabilities in multistable systems, and for providing crucial information on the possibility of transitions when forcing is present. We examine robustness, efficiency, and accuracy properties of the edge tracking algorithm. We find that the procedure is the most efficient when taking a single bisection per cycle. Due to the strong diffusivity of the system, the transient dynamics, is approximately confined to the heteroclininc trajectory, connecting the fixed unstable and stable states, after relatively short transient times. Such a constraint dictates a functional relationship between observables. We characterize such a relationship between the global average temperature and a descriptor of nonequilibrium thermodynamics, the large scale temperature gradient between low and high latitudes. We find that a maximum of the temperature gradient is realized at the same value of the average temperature, about 270 K, largely independent of the strength of incoming solar radiation. Due to this maximum, a transient increase and nonmonotonic evolution of the temperature gradient is possible and not untypical. We also examine the structural properties of the system defined by bifurcation diagrams describing the equilibria depending on a system parameter of interest, here the solar strength. We construct new bifurcation diagrams in terms of quantities relevant for describing thermodynamic properties such as the temperature gradient and the material entropy production due to heat transport. We compare our results for the energy balance model to results for the intermediate complexity general circulation model the Planet Simulator and find an interesting qualitative agreement. © 2014, Springer-Verlag Berlin Heidelberg. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54099
Appears in Collections: 过去全球变化的重建
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作者单位: Meteorological Institute, University of Hamburg, Hamburg, Germany; Department of Mathematics and Statistics, University of Reading, Reading, United Kingdom
Recommended Citation:
Bódai T.,Lucarini V.,Lunkeit F.,et al. Global instability in the Ghil–Sellers model[J]. Climate Dynamics,2015-01-01,44(2017-11-12)