Large-scale Structure and Turbulence Transport in the Inner Solar Wind -- Comparison of Parker Solar Probe's First Five Orbits with a Global 3D Reynolds-averaged MHD Model

TL;DR

This study compares a comprehensive 3D MHD model of the solar wind with Parker Solar Probe data over five orbits, showing good agreement in plasma and turbulence properties and advancing understanding of solar wind turbulence transport.

Contribution

The paper introduces a global 3D Reynolds-averaged MHD model that includes turbulence transport and compares its predictions with PSP observations, demonstrating its effectiveness.

Findings

Model accurately reproduces plasma parameters.

Synthetic turbulence distributions match observations.

Turbulence transport equations improve understanding of solar wind dynamics.

Abstract

Simulation results from a global magnetohydrodynamic model of the solar corona and solar wind are compared with Parker Solar Probe (PSP) observations during its first five orbits. The fully three-dimensional model is based on Reynolds-averaged mean-flow equations coupled with turbulence transport equations. The model includes the effects of electron heat conduction, Coulomb collisions, turbulent Reynolds stresses, and heating of protons and electrons via a turbulent cascade. Turbulence transport equations for average turbulence energy, cross helicity, and correlation length are solved concurrently with the mean-flow equations. Boundary conditions at the coronal base are specified using solar synoptic magnetograms. Plasma, magnetic field, and turbulence parameters are calculated along the PSP trajectory. Data from the first five orbits are aggregated to obtain trends as a function of heliocentric distance. Comparison of simulation results with PSP data shows good agreement, especially for mean-flow parameters. Synthetic distributions of magnetic fluctuations are generated, constrained by the local rms turbulence amplitude given by the model. Properties of this computed turbulence are compared with PSP observations.