Multi-fluid multi-species models for inverse FIP-effect

TL;DR

This paper explores the inverse FIP effect in the solar atmosphere using advanced multi-fluid MHD models, revealing conditions under which a negative ponderomotive force can occur due to magnetic and wave interactions.

Contribution

It introduces a comprehensive 1D multi-fluid MHD modeling approach to study the inverse FIP effect, moving beyond simplified wave analysis and semi-empirical models.

Findings

Negative ponderomotive force achieved with specific magnetic conditions.

Magnetic field strength and flux tube expansion influence the inverse FIP effect.

Multi-fluid interactions affect wave dissipation and damping.

Abstract

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 1D 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 1D models. In the parametric study considered here, for upward Alfv\'en 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.