Forces acting during the propagation of coronal mass ejections

Abstract

Coronal mass ejections (CMEs) are the main drivers of geomagnetic storms. Hence, prediction of their arrival time at Earth is of primary interest for understanding and improving Space Weather. To do this it is necessary to understand the forces acting during their propagation from the Sun to the Earth, such as the Lorentz hoop force and the aerodynamic drag. Some models, such as the erupting flux-rope from Chen et al. (1996) and drag-based model have been used to assess these forces and their parameters have been fitted to the observed data to account for the acceleration and deceleration of some CMEs. Although several publications have analyzed the propagation of CMEs, the forces are not completely understood and it remains challenging to anticipate the arrival time of a given CME. This proposal aims to study the force balance of CMEs using observations from the Heliospheric Imagers onboard the STEREO mission. We are specially interested in studying how the flux ropes entrained within CMEs evolve in the inner heliosphere.