Average Doppler shifts as a function of line-formation temperature. The diamonds show the average shifts of the synthesized Doppler map in the respective line, and the bars indicate the standard derivation of the Doppler shift in each map. The solid black line shows the average vertical velocity in the MHD model as a function of temperature. The black dashed line shows the trend from Peter & Judge (1999). The red dashed line indicates zero shift. See Sect. 3.4 for more details.