Could the collision of CMEs in the heliosphere be super-elastic? --- Validation through three-dimensional simulations

TL;DR

This study uses three-dimensional MHD simulations to verify whether CME collisions in the heliosphere are super-elastic, finding that such collisions can indeed result in a 3-4% increase in kinetic energy, indicating super-elastic behavior.

Contribution

The paper provides the first numerical validation that CME collisions can be super-elastic, challenging previous assumptions about their inelastic nature.

Findings

CME collisions can gain 3-4% kinetic energy.

Simulation results support super-elastic collision hypothesis.

Collision dynamics significantly affect space weather predictions.

Abstract

Though coronal mass ejections (CMEs) are magnetized fully-ionized gases, a recent observational study of a CME collision event in 2008 November has suggested that their behavior in the heliosphere is like elastic balls, and their collision is probably super-elastic \citep{Shen_etal_2012}. If this is true, this finding has an obvious impact on the space weather forecasting because the direction and veliocity of CMEs may change. To verify it, we numerically study the event through three-dimensional MHD simulations. The nature of CMEs' collision is examined by comparing two cases. In one case the two CMEs collide as observed, but in the other, they do not. Results show that the collision leads to extra kinetic energy gain by 3%--4% of the initial kinetic energy of the two CMEs. It firmly proves that the collision of CMEs could be super-elastic.