DOI: 10.1007/s00382-012-1316-1
Scopus记录号: 2-s2.0-84871919585
论文题名: Is the astronomical forcing a reliable and unique pacemaker for climate? A conceptual model study
作者: de Saedeleer B. ; Crucifix M. ; Wieczorek S.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2013
卷: 40, 期: 2017-01-02 起始页码: 273
结束页码: 294
语种: 英语
英文关键词: Climate models
; Generalised synchronisation
; Lyapunov exponent
; Milankovitch
; Multistability
; Oscillator
英文摘要: There is evidence that ice age cycles are paced by astronomical forcing, suggesting some kind of synchronisation phenomenon. Here, we identify the type of such synchronisation and explore systematically its uniqueness and robustness using a simple paleoclimate model akin to the van der Pol relaxation oscillator and dynamical system theory. As the insolation is quite a complex quasiperiodic signal involving different frequencies, the traditional concepts used to define synchronisation to periodic forcing are no longer applicable. Instead, we explore a different concept of generalised synchronisation in terms of (coexisting) synchronised solutions for the forced system, their basins of attraction and instabilities. We propose a clustering technique to compute the number of synchronised solutions, each of which corresponds to a different paleoclimate history. In this way, we uncover multistable synchronisation (reminiscent of phase- or frequency-locking to individual periodic components of astronomical forcing) at low forcing strength, and monostable or unique synchronisation at stronger forcing. In the multistable regime, different initial conditions may lead to different paleoclimate histories. To study their robustness, we analyse Lyapunov exponents that quantify the rate of convergence towards each synchronised solution (local stability), and basins of attraction that indicate critical levels of external perturbations (global stability). We find that even though synchronised solutions are stable on a long term, there exist short episodes of desynchronisation where nearby climate trajectories diverge temporarily (for about 50 kyr). As the attracting trajectory can sometimes lie close to the boundary of its basin of attraction, a small perturbation could quite easily make climate to jump between different histories, reducing the predictability. Our study brings new insight into paleoclimate dynamics and reveals a possibility for the climate system to wander throughout different climatic histories related to preferential synchronisation regimes on obliquity, precession or combinations of both, all over the history of the Pleistocene. © 2012 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54999
Appears in Collections: 过去全球变化的重建
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作者单位: Earth and Life Institute, Georges Lemaître Centre for Earth and Climate Research, Université catholique de Louvain, Louvain-la-Neuve, Belgium; Mathematics Research Institute, University of Exeter, Exeter, United Kingdom
Recommended Citation:
de Saedeleer B.,Crucifix M.,Wieczorek S.. Is the astronomical forcing a reliable and unique pacemaker for climate? A conceptual model study[J]. Climate Dynamics,2013-01-01,40(2017-01-02)