Non-ideal transport processes in the solar atmosphere

ABSTRACT Transport coefficients are calculated for a partially ionized plasma consisting of approximately $90{{\ \rm per\ cent}}$ hydrogen and $10{{\ \rm per\ cent}}$ helium, representative of a model solar atmosphere with an assumed magnetic field profile. The ion–Hall parameter, defined as the ratio of ion–cyclotron to ion collision frequency, is determined by considering dominant resonance charge exchange processes alongside less significant non-resonant ion–neutral collisions. Based on these calculations, we derive profiles for various transport coefficients. Our results demonstrate that thermal conductivity in partially ionized media – both parallel and perpendicular to the ambient magnetic field – is dominated by neutral particles. The perpendicular thermal conductivity components show weak dependence on the ion Hall parameter and remain comparable in magnitude to their parallel counterparts. Wave damping through neutral thermal conductivity may contribute significantly to solar atmospheric heating. These findings indicate that perpendicular thermal conductivity components are essential for accurate modeling of partially ionized regions, including photosphere-chromosphere transition layers, spicules, and coronal prominences.