We demonstrate the effect of a velocity shift of photospheric velocity fields in regions filled by magnetic field compared to the velocity fields of non-magnetic regions surrounding them. We analyze this effect on five different types of measurements in active region NOAA 8086 obtained by SOLMAG (Ondřejov magnetograph) in four spectral lines on September 18th, 1997.
The mean value of the Doppler velocity field in regions filled by magnetic field shows a red-shift of 40