A small step for the multi-fluid modeling of the solar atmosphere
Partially ionized plasmas exist in various astrophysical environments and give rise to a wide range of intriguing physical phenomena. In the solar atmosphere, in particular, partial ionization effects are crucial in understanding the dynamics of the chromosphere and prominences. The elements in the solar atmosphere can be in different ionization states and exhibit distinct dynamics, and thus a multi-fluid-multi-species (MFMS) magnetohydrodynamic (MHD) approach is essential for describing the solar atmosphere self-consistently. In this talk, I will first introduce Ebysus, an MFMS MHD code, and present recent progress, including new results on the First Ionization Potential (FIP) effect. I will then focus on a newly developed MFMS atmospheric model that provides quasi-steady gravitational settings for an arbitrary number of species at different excited levels and ionization stages, while accounting for ionization and recombination processes. Finally, I will briefly discuss our related ongoing studies and highlight their potential implications for understanding the solar atmosphere.
Fan Zhang received his Ph.D. in Computational Mechanics from Dalian University of Technology, China, where he specialized in numerical methods for fluid dynamics. His research subsequently expanded into computational MHD, with a particular focus on applications in solar and space physics. During his postdoctoral fellowship at KU Leuven, Fan contributed to the development of COCONUT (COolfluid COroNal UnsTructured), a global model of the solar corona (and recently the heliosphere), working on both its MHD and multi-fluid modules. He was later offered a fellowship from the Rosseland Centre for Solar Physics at the University of Oslo, and has been focusing on the development of numerical methods for MHD, including multi-fluid and multi-species models.