# Transient Inverse-FIP Plasma Composition Evolution within a Confined Solar Flare

## TL;DR

This study investigates how plasma composition, specifically FIP and inverse FIP effects, evolves during confined solar flares using spectroscopic data, revealing dynamic changes linked to magnetic reconnection and wave flux.

## Contribution

It provides the first detailed observation of transient plasma composition changes during confined flares and links these to magnetic and wave processes in emerging active regions.

## Key findings

- Plasma patches evolve from FIP to IFIP effect during flare decay.
- Loop tops show a stronger FIP effect compared to flare ribbons.
- Results support the ponderomotive fractionation model for IFIP plasma creation.

## Abstract

Understanding elemental abundance variations in the solar corona provides an insight into how matter and energy flow from the chromosphere into the heliosphere. Observed variations depend on the first ionization potential (FIP) of the main elements of the Sun's atmosphere. High-FIP elements (>10 eV) maintain photospheric abundances in the corona, whereas low-FIP elements have enhanced abundances. Conversely, inverse FIP (IFIP) refers to the enhancement of high-FIP or depletion of low-FIP elements. We use spatially resolved spectroscopic observations, specifically the Ar XIV/Ca XIV intensity ratio, from Hinode's Extreme-ultraviolet Imaging Spectrometer to investigate the distribution and evolution of plasma composition within two confined flares in a newly emerging, highly sheared active region. During the decay phase of the first flare, patches above the flare ribbons evolve from the FIP to the IFIP effect, while the flaring loop tops show a stronger FIP effect. The patch and loop compositions then evolve toward the pre-flare basal state. We propose an explanation of how flaring in strands of highly sheared emerging magnetic fields can lead to flare-modulated IFIP plasma composition over coalescing umbrae which are crossed by flare ribbons. Subsurface reconnection between the coalescing umbrae leads to the depletion of low-FIP elements as a result of an increased wave flux from below. This material is evaporated when the flare ribbons cross the umbrae. Our results are consistent with the ponderomotive fractionation model (Laming2015) for the creation of IFIP-biased plasma.