Results of the B-ω analysis of the LoS velocity field. Central panel: continuum intensity map showing the four RoIs. Panels (1–4): B-ω diagrams of the PSD of the LoS velocity field in the corresponding RoIs. The absolute value of the LoS magnetic field is plotted on the x-axes, and the frequency is plotted on the y axes. The same colour scale has been used for all these panels and is shown below the central panel. We have chosen the saturation levels in order to emphasise the power increases in the magnetic regions.