A Dynamical Model of Plasma Turbulence in the Solar Wind

TL;DR

This paper introduces a dynamical model of plasma turbulence in the solar wind that combines Alfven wave physics with current sheet development, providing new insights into energy transfer and damping in weakly collisional plasmas.

Contribution

It presents the first self-consistent dynamical model linking Alfven wave dynamics with small-scale current sheet formation in kinetic plasma turbulence.

Findings

Highlights the fluid-like nature of energy cascade and current sheet formation.

Shows collisionless damping and kinetic instabilities are key kinetic processes.

Provides a new perspective on turbulence in weakly collisional plasmas.

Abstract

A dynamical approach, rather than the usual statistical approach, is taken to explore the physical mechanisms underlying the nonlinear transfer of energy, the damping of the turbulent fluctuations, and the development of coherent structures in kinetic plasma turbulence. It is argued that the linear and nonlinear dynamics of Alfven waves are responsible, at a very fundamental level, for some of the key qualitative features of plasma turbulence that distinguish it from hydrodynamic turbulence, including the anisotropic cascade of energy and the development of current sheets at small scales. The first dynamical model of kinetic turbulence in the weakly collisional solar wind plasma that combines self-consistently the physics of Alfven waves with the development of small-scale current sheets is presented and its physical implications are discussed. This model leads to a simplified perspective on the nature of turbulence in a weakly collisional plasma: the nonlinear interactions responsible for the turbulent cascade of energy and the formation of current sheets are essentially fluid in nature, while the collisionless damping of the turbulent fluctuations and the energy injection by kinetic instabilities are essentially kinetic in nature.