Noise Intensity and Waiting Time Distributions at the Dansgaard-Oeschger Transitions as an Identification of Triggering Mechanism for Climate Shifts

The transitions into and out of the interstadials are triggered by internal variability in the climate inducing shifts between two stable states of the Atlantic termohaline circulation. By studying the variability of the high resolution δ¹⁸O record at the transition and the waiting time distribution it is possible to distinguish between climatic shifts governed by a stochastic resonance as proposed recently, or if the transitions are purely a result of a barrier penetration triggered by the internal climatic noise. The difference is seen by applying a fluctuation-dissipation theorem for the transition. The results indicate that the distinction between the two models can be made and the transitions should rather be described by the latter scenario.