Comparison between diffusion (thin lines) and advection (thick lines) timescales for the Kraichnan (green dashed lines) and Bohm (blue solid lines) cases. The black dotted line shows the diffusion time in the case of a diffusion coefficient with the same slope as that in the standard interstellar medium normalised a factor of 100. All timescales are calculated considering only the region used for the morphological analysis, i.e. substituting R_b with 54 pc in Eqs. (20) and (21).