Coronal Mass Ejections and Dimmings: A Comparative Study using MHD Simulations and SDO Observations

TL;DR

This study combines MHD simulations and SDO observations to analyze coronal dimmings associated with CMEs, revealing their physical origins and potential for CME detection in distant stars.

Contribution

It introduces a data-constrained MHD simulation approach to study coronal dimmings and links dimming patterns with CME properties, enhancing understanding of CME-dimming relationships.

Findings

Dimming/brightening relate to plasma heating processes.

Long-lasting dimmings are caused by CME-induced mass loss.

Dimming metrics correlate with CME mass and speed.

Abstract

Solar coronal dimmings have been observed extensively in the past two decades. Due to their close association with coronal mass ejections (CMEs), there is a critical need to improve our understanding of the physical processes that cause dimmings as well as their relationship with CMEs. In this study, we investigate coronal dimmings by combining simulation and observational efforts. By utilizing a data-constrained global magnetohydrodynamics model (AWSoM: Alfven-wave Solar Model), we simulate coronal dimmings resulting from different CME energetics and flux rope configurations. We synthesize the emissions of different EUV spectral bands/lines and compare with SDO/AIA and EVE observations. A detailed analysis of the simulation and observation data suggests that the transient dimming / brightening are related to plasma heating processes, while the long-lasting core and remote dimmings are caused by mass loss process induced by the CME. Moreover, the interaction between the erupting flux rope with different orientations and the global solar corona could significantly influence the coronal dimming patterns. Using metrics such as dimming depth and dimming slope, we investigate the relationship between dimmings and CME properties (e.g., CME mass, CME speed) in the simulation. Our result suggests that coronal dimmings encode important information about the associated CMEs, which provides a physical basis for detecting stellar CMEs from distant solar-like stars.