Investigating the influence of the source-sink terms in a two-fluid global coronal model

Context. Global multi-fluid coronal models are crucial to enhancing our comprehension and prediction of space weather. This study offers new insights into the impact of source and sink terms in a two-fluid model of the partially ionised solar atmosphere and their implications for the dynamics of the solar corona, in the context of space-weather forecasting. Aims. This study aims to extend the two-fluid global coronal model by incorporating source and sink terms that represent empirical formulations of coronal heating and radiative and thermal conduction losses. The paper presents a fresh perspective by comparing model performance with and without these terms in a two-fluid (ion-neutral) plasma framework. Methods. This work employed the newly developed multi-fluid global coronal model, COolfluid COronal uNstrUcTure Multi-Fluid (COCONUT-MF), based on the Computational Object-Oriented Libraries for Fluid Dynamics (COOLFluiD) code. This code solves the equations separately for charged particles (ions + electrons) and the neutral gas to describe the dynamics of a partially ionized plasma. The model in this paper accounted for chemical (ionization and recombination) and non-ideal (collisional) dynamics due to neutrals, as well as empirical heating terms, thermal conduction, and radiative losses, which were incorporated into the energy equation. Results. The paper discusses two steady-state solutions: one for a solar-minimum case (August 1, 2008) and one for a solar-maximum case (March 9, 2016). We demonstrate the importance of accounting for source-sink terms in two-fluid models to accurately describe the dynamics of the lower corona. Conclusions. The obtained results underscore the necessity of incorporating source-sink terms in the accurate modelling of the dynamics of the solar corona. Such terms lead to more structured temperature profiles and improved predictions for space weather.