Novel two-fluid modelling of chromospheric heating and magnetic reconnection phenomena.

The solar chromosphere is a complex and still poorly understood thin plasma layer (2Mm thick) between the relatively cool solar photosphere (around 5000K) and the hot corona (around 1MK). The energy is transferred from the underlying photosphere and convection zones through the chromosphere into the corona, which means that the energy transport mechanisms in the chromosphere are fundamental for the coronal heating problem, the origin of the solar wind, etc.The chromospheric plasma is weakly or partially ionized and is not in local thermodynamical equilibrium. The partially ionized plasma includes a large portion of neutrals, which frequently exceeds the amount of ions. 2D two-fluid models are well developed in the group but they do not yet take into account of magnetic reconnection occurring in 3D, neither high-frequency waves due to relatively low resolution in the model.In this project, (1) an advanced ion-neutral two-fluid 3D model will be developed and used to describe the detailed physics, including e.g. partial ionization effects, non-equilibrium ionization, and (2) a high-order numerical solver with adaptive mesh refinement will be implemented to solved the resolution problem. Eventually, self-consistent two-fluid modelling of 3D energy transfers in the chromosphere by wave propagation and magnetic reconnection will be proceeded, and will provide a better understanding structure and heating of the chromosphere of the Sun, and thus of other Sun-like stars.

Keywords:solar chromosphere, two-fluid plasma model, , high-order accurate numerical method

Disciplines:Space plasma physics and solar physics, Computational physics, Numerical computation