Snapshot of coronal loop and field lines studied here. The background image shows the synthesized EUV emission as it would be seen in the 193 Å channel of AIA showing mainly 1.5 MK hot plasma. Overplotted are twelve selected magnetic field lines (red) within the EUV loop. This shows a snapshot at time t = 12.5 min based on the data from the model by Chen et al. (2014, 2015). The two panels show a view from straight above (top panel) and the side (bottom panel) of part of the computational domain; we refer to Sect. 2.