Doppler map (left panel) of AR11641 on 2 January 2013 at 07:30 UT. The green line displays the outline of the spot, and exemplary ellipses, along which the velocity values are read out, are plotted in black. The extension of the flow field is delimited by velocities higher than the rms values (green curve in the right panel). The rms values are plotted as error bars. The blue curve represents the velocity profile corrected for projection effects.