Phase-mixing v.s. phase synchronization in the dynamics of flow-shear induced edge transport barrier

TL;DR

This paper analyzes the mechanisms behind nonlinear oscillations in flow-shear induced transport barriers, focusing on phase synchronization and phase mixing, using an extended model with stochastic elements.

Contribution

It provides a detailed analysis of phase synchronization versus phase mixing in nonlinear oscillations within an extended, stochastic model of transport barriers.

Findings

Nonlinear oscillations are driven by phase synchronization mechanisms.

Random fluctuations influence the stability of phase-locked states.

Extended model captures complex dynamics of flow-shear induced barriers.

Abstract

Nonlinear relaxation oscillations of flow-shear induced transport barriers can be qualitatively reproduced using a phenomenological critical-gradient model [M. Leconte, Y.M. Jeon and G.S. Yun, \emph{Contrib. Plasma Phys.} 56, 736 (2016]. Here, we give a more in-depth analysis of the mechanism of these nonlinear oscillations, associated to nonlinear \emph{phase synchronization}, in an extended version of the model including random fluctuations.