Effect of the latitudinal distribution of temperature at the coronal base on the interplanetary magnetic field configuration and the solar wind flow

摘要

Using a two-dimensional MHD model of the corona and solar wind, we investigate the role of the temperature distribution with latitude at the coronal base on the global magnetic field configuration and solar wind properties at 1 AU. The latitudinal distribution of temperature is aimed at modeling the transition in electron temperature at the Sun from a polar coronal hole to the quiet Sun to active regions. The results of the model calculations illustrate how the variation of temperature with latitude impacts the coronal magnetic field configuration and the distribution of wave energy flux in the solar wind and consequently its thermodynamic properties. The sharp temperature changes at the coronal base lead to the formation of current sheets in the corona. They also modify the location of the streamer cusp and the neutral line originating there. Two different approaches in treating electron heat flux are also compared, one assumes a Spitzer expression throughout the computational domain and the other assumes a collisionless expression beyond some radial distance. Model results thus derived differ little in terms of proton flux and terminal speed.