Alfvenic Perturbations in a Sunspot Chromosphere Linked to Fractionated Plasma in the Corona

TL;DR

This study links chromospheric Alfvenic perturbations in a sunspot to plasma fractionation in the corona, revealing magnetic connections that influence plasma composition variations.

Contribution

It provides new insights into how chromospheric activity correlates with plasma composition changes in the corona through magnetic field analysis.

Findings

Coronal plasma above the sunspot umbra has photospheric composition.

Loops in the penumbra show fractionated plasma, especially within active regions.

Magnetic field lines connect chromospheric fluctuations to coronal plasma composition.

Abstract

In this study, we investigate the spatial distribution of highly varying plasma composition around one of the largest sunspots of solar cycle 24. Observations of the photosphere, chromosphere, and corona are brought together with magnetic field modelling of the sunspot in order to probe the conditions which regulate the degree of plasma fractionation within loop populations of differing connectivities. We find that in the coronal magnetic field above the sunspot umbra, the plasma has photospheric composition. Coronal loops rooted in the penumbra contain fractionated plasma, with the highest levels observed in the loops that connect within the active region. Tracing field lines from regions of fractionated plasma in the corona to locations of Alfvenic fluctuations detected in the chromosphere shows that they are magnetically linked. These results indicate a connection between sunspot chromospheric activity and observable changes in coronal plasma composition.