Energy input in solar flares and coronal explosions

A coronal explosion is a density wave observed in X-ray images of solar flares. The wave occurs at the end of the impulsive phase, which is the time at which the flare's thermal energy content has reached its maximum value. It starts in a small area from where it spreads out, mainly into one hemisphere, with velocities that tend to rapidly decrease with time, and which are between ～ 10³ and a few tens of km s^?1. We interpret them as magneto-hydrodynamic waves that (mainly) move downward from the low corona into denser regions.