INCORPORATING KINETIC PHYSICS INTO A TWO-FLUID SOLAR-WIND MODEL WITH TEMPERATURE ANISOTROPY AND LOW-FREQUENCY ALFVÉN-WAVE TURBULENCE

Abstract

We develop a 1D solar-wind model that includes separate energy equations for\nthe electrons and protons, proton temperature anisotropy, collisional and\ncollisionless heat flux, and an analytical treatment of low-frequency,\nreflection-driven, Alfven-wave turbulence. To partition the turbulent heating\nbetween electron heating, parallel proton heating, and perpendicular proton\nheating, we employ results from the theories of linear wave damping and\nnonlinear stochastic heating. We account for mirror and oblique firehose\ninstabilities by increasing the proton pitch-angle scattering rate when the\nproton temperature anisotropy exceeds the threshold for either instability. We\nnumerically integrate the equations of the model forward in time until a steady\nstate is reached, focusing on two fast-solar-wind-like solutions. These\nsolutions are consistent with a number of observations, supporting the idea\nthat Alfven-wave turbulence plays an important role in the origin of the solar\nwind.\n