Three-fluid model of the heating and acceleration of the fast solar wind

Abstract

A new three-fluid, two-dimensional, wave-driven model that includes, for the first time, heat conduction, viscous, and resistive dissipation for protons and electrons in two-dimensional coronal hole is presented. The fast solar wind model includes electron, proton, and He⁺⁺ or O⁵⁺ ion fluids. The heating of the solar wind plasma due to MHD waves is modeled as follows: A broadband spectrum of low-frequency Alfvén waves is launched from the base of the corona. The waves deposit momentum and heat into the plasma to produce the fast solar wind. The values of the resistivity and shear viscosity coefficients required to produce the hot and fast solar wind consistent with observations are orders of magnitude larger than classical values. An empirical heating term that represents the contribution of additional heating processes, such as resonant heating by ion cyclotron waves, is included for the heavy ions and for protons in three out of four cases in the present study.