Time-series at a single pixel within the sunspot is shown in the top three-panels, in Stokes I (top left) and V (top middle). The top-right panel corresponds to a synthetic Stokes V profile computed using the weak-field approximation to fit B_l.o.s. In both cases, the Stokes V profiles are scaled identically between ± 2.2% relative to the average quiet-Sun continuum intensity. The resulting longitudinal magnetic field strenght is plotted in the second row (solid-grey line). We have smoothed that result using a median filter of 3 time-steps, which is illustrated with a black-crossed line. For clarity, the lowermost panels illustrate the Stokes I and V profiles at a quiescent state (black) and during the UF (blue).