The Relationship between the Kinematics of Coronal Mass Ejections and the Brightness of the Corona

TL;DR

This study investigates the link between coronal brightness and CME speed, revealing that higher brightness levels may indicate lower CME velocities, with implications for understanding solar eruptions and space weather prediction.

Contribution

It introduces the LASCO Coronal Brightness Index dataset to analyze the relationship between coronal brightness and CME kinematics, highlighting brightness as a potential predictor.

Findings

Higher coronal brightness correlates with lower CME velocities.

Active Region 12192's brightness may explain its low CME activity.

Brightness levels can serve as indicators for CME likelihood and speed.

Abstract

We present an investigation into an apparent relationship between white-light coronal brightness and the kinematics of flare-associated CMEs. Using a unique dataset known as the LASCO Coronal Brightness Index (CBI), we conduct a study that explores the brightness in the lower solar corona and its relationship to the velocity of flare-associated coronal mass ejections (CMEs). We analyze all M- and X-class flares that take place on or near the limbs of the Earth-facing disk of the Sun between 1996 and 2022, determine if these flares are associated with CMEs, and record the projection-corrected velocity of the eruptions if they occurred. Using the CBI dataset, we evaluate the brightness in the corona directly overlying the flare source locations between 2.4 and 6.2 solar radii, and find that above a certain level of coronal brightness, the likelihood of a high-velocity CME significantly decreases. This result implies coronal brightness could be an important indicator of the kinematics of solar CMEs. We also highlight and discuss the unique nature of Active Region (AR) 12192 in 2014, observing that its unprecedented overlying coronal brightness may be related to the low CME productivity of that region.