Monday, December 6, 2010

Excitability in ramped systems: the compost-bomb instability

Excitability in ramped systems: the compost-bomb instability

The paper studies a novel excitability type where a large excitable response appears when a system’s parameter is varied gradually, or ramped, above some critical rate. This occurs even though there is a (unique) stable quiescent state for any fixed setting of the ramped parameter. We give a necessary and a sufficient condition for the existence of a critical ramping rate in a general class of slow–fast systems with folded slow (critical) manifold. Additionally, we derive an analytical condition for the critical rate by relating the excitability threshold to a canard trajectory through a folded saddle singularity. The general framework is used to explain a potential climate tipping point termed the ‘compost-bomb instability’—an explosive release of soil carbon from peatlands into the atmosphere occurs above some critical rate of global warming even though there is a unique asymptotically stable soil carbon equilibrium for any fixed atmospheric temperature.

2 comments:

  1. Somebody has got to get a copy of this.

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  2. Well, you know, this is not only true for methane, although it may be the most near-term problem, much nearer than sea-level rise or ocean acidification, or well, you name it.

    Anyway, this is not the first paper on catastrophic tipping points.

    Hope you find a copy.

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