Magnetograms at the photosphere (z = 0) in the Bifrost simulation. (a) is just after the relaxation of the QS. (b) is just after the ramp of the LFFF. The white polarity (north pole) signifies flux coming out of the solar surface, being negative here as z is positive along the LOS. The black polarity (south pole) signifies flux entering the solar surface. The associated movie is available online