Relaxation of the turbulent magnetosheath

TL;DR

This paper presents observational evidence that turbulence in Earth's magnetosheath can locally relax into quasi-equilibrium states, forming patches where energy transfer is reduced, revealing a new aspect of turbulence behavior.

Contribution

It demonstrates for the first time that turbulence can relax locally into quasi-equilibrium states in a natural environment, showing cellularization of turbulence.

Findings

Evidence of local relaxation in magnetosheath turbulence

Formation of patches with reduced nonlinearity

Impairment of energy cascade in localized regions

Abstract

In turbulence, nonlinear terms drive energy transfer from large-scale eddies into small scales through the so-called energy cascade. Turbulence often relaxes toward states that minimize energy; typically these states are considered globally. However, turbulence can also relax toward local quasi-equilibrium states, creating patches or cells where the magnitude of nonlinearity is reduced and energy cascade is impaired. We show, for the first time, compelling observational evidence that this ``cellularization'' of turbulence can occur due to local relaxation in a strongly turbulent natural environment such as the Earth's magnetosheath.