The physical mechanisms that trigger coronal mass ejections

Author: Francesco Zuccarello

Affiliation: Observatoire de Paris, Paris

Solar filaments are magnetic structures often observed in the solar atmosphere and consisting of plasma that is cooler and denser than their surroundings. They are visible for days – and even weeks – which suggests that they are often in equilibrium with their environment before erupting, resulting in flares and associated coronal mass ejections (CMEs).
When a CME lifts-off a huge amount of magnetized plasma it is ejected from the Sun into the interplanetary medium, eventually resulting in hazardous space weather conditions.
After introducing the theoretical background of the different CME’s initiation models I will review the results of recent numerical magnetohydrodynamic simulations aimed to determine the physical mechanism that trigger solar eruptions and the key parameters for the occurrence of CMEs. I will conclude by discussing how these criteria derived from the models relates —and apply— to actual observations of eruptive flares.