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

Abstract

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 modeling of the sunspot in order to probe the conditions that 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 Alfvénic 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.