Solar Wind Acceleration in a Three Temperature, Alfven Wave-driven Solar Wind Model

We present the solar wind simulations from the corona to 1 AU using our newly developed 3D Alfven wave-driven solar wind model with anisotropic proton temperature and isotropic electron temperature. We find good agreements when comparing the simulated solar wind properties at 1 AU to the observation by the ACE, WIND, and STEREO satellites during both solar minimum and maximum. With the new model, we investigate the proton temperature anisotropy distribution and the firehose instability in the corona and heliosphere, as well as the impact of the temperature anisotropy on the solar wind acceleration. In particular, we show that including proton temperature anisotropy in a two-temperature solar wind model leads to slower and more realistic solar wind speeds. In addition, we point out that the proton temperature anisotropy could also affect the solar wind speed through a modified wave pressure gradient term in the momentum equation, which will be addressed in our future model.