Temporal evolution of the vertical magnetic-field component in the photosphere beneath the jet. (a) Zoomed-in FOV of the magnetogram beneath the jet. (b) Sums of the absolute values of positive (orange curve) and negative (blue curve) polarities in the red box outlined in (a). The vertical dashed gray line indicates the time of the magnetogram shown in (a). An animation is available online. See Sect. 3.2.