Beyond Lateral Expansion: A Multi-parameter Regression-based Model for Inferring Radial Propagation Speeds and Transit Time of Coronal Mass Ejections

Abstract

Coronal mass ejections (CMEs) have an important kinematic parameter: the propagation speed (Vp), which can be used to determine the transit time of Earth-directed CMEs. This study examines the association between the propagation speed (Vp) and the expansion speeds of 183 interplanetary coronal mass ejections (ICMEs) from 2009 to 2023. We used multiple regression analyses to demonstrate that the Vp of the ICME may be inferred from more than the lateral expansion speed (Vlat). Four regression-based model (RGBM) equations were derived using the solar wind speed (Vsw), the angular width (AW), bulk expansion (Vblk), front expansion (Vfrt), and lateral expansion (Vlat) speeds of the CME to estimate both the Vp and transit times of near-Earth-directed ICMEs/shock. A total of 28 halo ICMEs were used to validate RGBM equations. The most accurate calculation yielded a 6.43-hour mean absolute error (MAE). A feed-forward neural network (FFNN) model was used to estimate the transit times of the 28 halo ICMEs, with an observed MAE of 4.56 hrs. The propagation speed of the RGBM equations that produced the lowest MAE was incorporated into the drag-based model (DBM) to determine the transit times of ICMEs/shocks. The MAE associated with the DBM was found to be 6.03 hrs.