Intermittency of Energy Dissipation in Alfvenic Turbulence

TL;DR

This paper studies the intermittency of energy dissipation in Alfvenic turbulence through numerical simulations and solar wind data, comparing two statistical models to understand their effectiveness in describing turbulence characteristics.

Contribution

It provides a detailed comparison of log-normal and log-Poisson models in describing energy dissipation intermittency in Alfvenic turbulence, using both simulations and observational data.

Findings

Log-normal model fits the PDF of energy dissipation well across scales.

Log-Poisson model better captures the scaling exponents of moments.

Neither model perfectly describes all aspects of turbulence intermittency.

Abstract

We investigate the intermittency of energy dissipation in Alfvenic turbulence by considering the statistics of the coarse-grained energy dissipation rate, using direct measurements from numerical simulations of magnetohydrodynamic turbulence and surrogate measurements from the solar wind. We compare the results to the predictions of the log-normal and log-Poisson random cascade models. We find that, to a very good approximation, the log-normal model describes the probability density function for the energy dissipation over a broad range of scales, but does not accurately describe the scaling exponents of the moments. The log-Poisson model better describes the scaling exponents of the moments, while the comparison with the probability density function is not straightforward.