Mass Loss Evolution in the EUV Low Corona from SDO/AIA Data

TL;DR

This study analyzes the mass loss in the low corona during coronal dimming events associated with CMEs, revealing that a significant portion of CME mass originates from the low corona and that mass evacuation continues as CMEs propagate.

Contribution

It introduces a differential emission measure technique to quantify evacuated mass in coronal dimmings and links low corona mass loss to CME evolution.

Findings

Evacuated mass from the low corona accounts for a significant part of CME mass.

Mass evacuation continues during CME propagation into the outer corona.

Temporal parameters like CME width and X-ray flux correlate with mass loss dynamics.

Abstract

We carry out an analysis of the evacuated mass from three coronal dimming regions observed by the {\it Atmospheric Imaging Assembly} (AIA) on board the {\it Solar Dynamics Observatory}. The three events are unambiguously identified with white-light coronal mass ejections (CMEs) associated in turn with surface activity of diverse nature: an impulsive (M-class) flare, a weak (B-class) flare and a filament eruption without a flare. The use of three AIA coronal passbands allows applying a differential emission measure technique to define the dimming regions and identify their evacuated mass through the analysis of the electronic density depletion associated to the eruptions. The temporal evolution of the mass loss from the three dimmings can be approximated by an exponential equation followed by a linear fit. We determine the mass of the associated CMEs from COR2 data. The results show that the evacuated masses from the low corona represent a considerable amount of the mass of the CMEs. We also find that plasma is still being evacuated from the low corona at the time when the CMEs reach the COR2 field of view. The temporal evolution of the angular width of the CMEs, of the dimming regions in the low corona, and of the flux registered by GOES in soft X-rays are all in close relation with the behavior of mass evacuation from the low corona. We discuss the implications of our findings toward a better understanding of the temporal evolution of several parameters associated to the analyzed dimmings and CMEs.