Multi-fluid multi-species models for inverse first ionization potential effect

The inverse first ionization potential (FIP) effect is rarely observed in the solar atmosphere, and this anomaly poses a challenging problem in understanding physical processes driving this chemical fractionation. In this work, we investigate various scenarios where the inverse FIP effect could occur using simplified one-dimensional multi-fluid MHD models. The model treats the full MHD equations with multi-fluid and multi-species effects, rather than using wave analysis to derive the ponderomotive force and semi-empirical one-dimensional models. In the parametric study considered here, for upward Alfvén waves, one can achieve a negative (opposite) ponderomotive force when the magnetic field strength and the magnetic flux tubes' expansion with height counteract the dissipation and damping effects from multi-fluid interactions. This article is part of the Theo Murphy meeting issue ‘Solar atmospheric abundances in space and time’.