Three-Dimensional Parameters of the Earth-Impacting CMEs Based on the GCS Model

Abstract

When a CME arrives at the Earth, it will interact with the magnetosphere, sometimes causing hazardous space weather events. Thus, the study of CMEs which arrived at Earth (hereinafter, Earth-impacting CMEs) has attracted much attention in the space weather and space physics communities. Previous results have suggested that the three-dimensional parameters of CMEs play a crucial role in deciding whether and when they reach Earth. In this work, we use observations from the Solar TErrestrial RElations Observatory (STEREO) to study the three-dimensional parameters of 71 Earth-impacting CMEs from the middle of 2008 to the end of 2012. We find that the majority Earth-impacting CMEs originate from the region of [30S,30N] × [40E,40W] on the solar disk; Earth-impacting CMEs are more likely to have a central propagation angle (CPA) no larger than half-angular width, a negative correlation between velocity and acceleration, and propagation time is inversely related to velocity. Based on our findings, we develop an empirical statistical model to forecast the arrival time of the Earth-impacting CME. Also included is a comparison between our model and the aerodynamic drag model.

Collection, Collation, and Comparison of 3D Coronal CME Reconstructions

“…22. Zhong (Zhong et al, 2021)-This work uses the GCS technique to reconstruct Earth-impacting CMEs from the corresponding STEREO coronagraph observations. Their fits include several reconstructions from the Shen catalog, which we do not include as duplicates within LLAMACoRe.…”

“…It includes reconstructions from both the AFFECTS and Majumdar catalogs, so we remove any overlapping cases to make sure the results are not duplicated within LLAMACoRe. Wood (Wood et al., 2017)—This work connects coronal CME observations with in situ observations of magnetic clouds. The CMEs are reconstructed from STEREO coronagraph imagery using the technique from Wood and Howard (2009), which is conceptually similar to visually aligning the GCS shape, but employs a different set of equations defining the shape. Zhong (Zhong et al., 2021)—This work uses the GCS technique to reconstruct Earth‐impacting CMEs from the corresponding STEREO coronagraph observations. Their fits include several reconstructions from the Shen catalog, which we do not include as duplicates within LLAMACoRe. ZhuangGCS (Zhuang et al., 2017)—This work uses coronal reconstructions of CMEs as an input to the Integrated CME‐Arrival forecasting system.…”