3D radiative MHD simulations of coronal rain formation and evolution

Coronal rain is formed in footpoint-heated loops as a result of thermal instability. Recent observations have shown that coronal rain is much more common than previously thought, suggesting its important role in the chromosphere-corona mass cycle. We present 3D radiative MHD simulations of coronal rain formation and evolution using Bifrost. The simulation includes optically thick non-LTE radiative transfer in the photosphere and low chromosphere, parametrized radiative gains and losses in the upper layers of the solar atmosphere, as well as the effects of non-equilibrium ionisation of the hydrogen. The chromosphere and corona in the simulation are self-consistently heated by Joule and viscous heating due to magnetic field braiding from convective motions. We investigate the spatial and temporal evolution of energy dissipation along the loops and the relation between development of thermal instability and impulsive heating events. We further address the evolution of the cooling of the coronal rain condensations and how this compares to the temperature evolution of coronal rain inferred from the observations.