Coexisting stochastic and coherence resonance in a mean-field dynamo model for Earth's magnetic field reversals

TL;DR

This paper demonstrates the coexistence of coherence resonance and stochastic resonance in a mean-field dynamo model for Earth's magnetic field reversals, providing insights into the timing and mechanisms of geomagnetic reversals.

Contribution

It introduces a spherical symmetric mean-field alpha^2-dynamo model that captures both noise-induced resonance phenomena relevant to Earth's magnetic reversals.

Findings

Coexistence of coherence and stochastic resonance in the model

Estimated Earth's core diffusion time as around 100 kyr

Model aligns with paleomagnetic reversal distribution

Abstract

Using a spherical symmetric mean field alpha^2-dynamo model for Earth's magnetic field reversals, we show the coexistence of the noise-induced phenomena coherence resonance and stochastic resonance. Stochastic resonance has been recently invoked to explain the 100 kyr periodicity in the distribution of the residence time between reversals. The comparison of the resulting residence time distribution with the paleomagnetic one allows for some estimate of the effective diffusion time of the Earth's core which may be 100 kyr or slightly below rather than 200 kyr as it would result from the molecular resistivity.