Electron and proton heating by solar wind turbulence

TL;DR

This paper extends models of solar wind turbulence heating to include separate electron and proton energy equations, demonstrating that turbulence deposits heat unevenly and heat conduction significantly influences electron temperature data.

Contribution

It introduces a generalized framework for electron and proton heating in solar wind turbulence, incorporating separate energy equations and empirical heat conduction effects.

Findings

Turbulent heating deposits 60% to protons and 40% to electrons.

Long energy exchange timescales are consistent with data.

Heat conduction significantly impacts electron temperature modeling.

Abstract

Previous formulations of heating and transport associated with strong magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate internal energy equations for electrons and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both electrons and protons, and is exchanged between them via collisions. Comparison to available Ulysses data shows that a reasonable accounting for the data is provided when (i) the energy exchange timescale is very long and (ii) the deposition of heat due to turbulence is divided, with 60% going to proton heating and 40% into electron heating. Heat conduction, determined here by an empirical fit, plays a major role in describing the electron data.