Fortelling catastrophes?

TL;DR

This paper introduces a saddle-node bifurcation model to describe rapid geophysical transitions, highlighting precursor signals like increased correlation length and spectral shifts that could enable early catastrophe detection.

Contribution

It presents a generic bifurcation model capturing precursor phenomena and fluctuation changes associated with fast transitions in geophysical systems.

Findings

Correlation length increases before transitions

Spectral drift towards lower frequencies prior to events

Precursor signals could aid early detection of catastrophes

Abstract

A generic saddle-node bifurcation is proposed to modelize fast transitions of finite amplitude arising in geophysical (and perhaps other) contexts, when they result from the intrinsic dynamics of the system. The fast transition is generically preceded by a precursor phase which is less rapid, that we characterize. In this model, if an external source of noise exist, the correlation length of the fluctuations increases before the transition, and its spectrum tends to drift towards lower frequencies. This change in the fluctuations could be a way of detecting catastrophic events before they happen.