The chromosphere in internetwork regions of the quiet Sun was regarded as a static and homogeneous layer for a long time .
Thanks to advances in observations and numerical modelling , the wave nature of these atmospheric regions received increasing attention during the last decade .
Recent three-dimensional radiation magnetohydrodynamic simulations with CO5BOLD feature the chromosphere of internetwork regions as a dynamic and intermittent phenomenon .
It is a direct product of interacting waves that form a mesh-like pattern of hot shock fronts and cool post-shock regions .
The waves are excited self-consistently at the top of the convection zone .
In the middle chromosphere above an average height of 1000 km , plasma beta gets larger than one and magnetic fields become more important .
The model chromosphere exhibits a magnetic field that is much more homogeneous than in the layers below and evolves much faster .
That includes fast propagating ( MHD ) waves .
Further improvements of the simulations like time-dependent hydrogen ionisation are currently in progress .
This class of models is capable of explaining apparently contradicting diagnostics such as carbon monoxide and UV emission at the same time .