Plasma flow velocity and magnetic field in vortices. Left: vertical component of flow velocity (v_z) at the τ = 1 layer with black contours of B_z ranging from 400 G to 2500 G and a red box highlighting one magnetic element (right panel), where the image at the bottom now shows the vertical component of the field, B_z, instead of v_z in the left panel. Right: 3D view of a sub-domain covering the volume 1.4 Mm × 1.4 Mm × 2.5 Mm corresponding to the red square in the left panel. Velocity streamlines and magnetic field lines are shown in sea green and deep purple, respectively, at the selected vortex locations. A perpendicular cut at 1.5 Mm above the surface is indicated by the pink plane whose vortex properties will be shown and discussed later in the paper.