Effective Viscosity, Resistivity, and Reynolds Number in Weakly Collisional Plasma Turbulence

TL;DR

This paper investigates energy dissipation and conversion in weakly collisional plasma turbulence using MMS observations and kinetic simulations, revealing effective viscosity, resistivity, and Reynolds numbers that connect macro turbulence with kinetic plasma properties.

Contribution

It introduces a method to determine effective viscosity, resistivity, and Reynolds numbers in weakly collisional plasma turbulence, linking macro turbulence features with kinetic plasma characteristics.

Findings

Identification of viscous-like and resistive-like scaling in energy conversion rates

Extraction of effective viscosity and resistivity coefficients

Establishment of a link between turbulence bandwidth and kinetic plasma properties

Abstract

We examine dissipation and energy conversion in weakly collisional plasma turbulence, employing in situ observations from the Magnetospheric Multiscale (MMS) mission and kinetic Particle-in-Cell (PIC) simulations of proton-electron plasma. A previous result indicated the presence of viscous-like and resistive-like scaling of average energy conversion rates -- analogous to scalings characteristic of collisional systems. This allows for extraction of collisional-like coefficients of effective viscosity and resistivity, and thus also determination of effective Reynolds numbers based on these coefficients. The effective Reynolds number, as a measure of the available bandwidth for turbulence to populate various scales, links macro turbulence properties with kinetic plasma properties in a novel way.