Intermittency in spherical Couette dynamos

TL;DR

This paper studies intermittent magnetic field behavior in turbulent spherical Couette flows near dynamo onset, revealing on-off intermittency with realistic boundary conditions through numerical simulations.

Contribution

It demonstrates the occurrence of on-off intermittency in spherical Couette dynamos with realistic boundary conditions, a novel insight into magnetic field fluctuations.

Findings

Magnetic field exhibits intermittent bursts near dynamo threshold.

On-off intermittency is identified as the underlying mechanism.

Boundary conditions influence the intermittency behavior.

Abstract

We investigate dynamo action in three-dimensional numerical simulations of turbulent spherical Couette flows. Close to the onset of dynamo action, the magnetic field exhibits an intermittent behavior, characterized by a series of short bursts of the magnetic energy separated by low-energy phases. We show that this behavior corresponds to the so-called on-off intermittency. This behavior is here reported for dynamo action with realistic boundary conditions. We investigate the role of magnetic boundary conditions in this phenomenon.