Same plots as Fig. 6, but for observations of merging MBPs leading to magnetic field amplification. The temporal evolution of the magnetic field shows how complicated MBP evolution is due to various factors. The intensity images in panel a help demonstrate this complex behaviour. Orange contours in the intensity images show the MBP, as tracked by our algorithm, used to make the evolution plots above. Green contours indicate the other MBP involved in the merger. The first small peak in magnetic field (at ∼1300 G) is due to a merging of two MBPs. The intensity images show the motion of several MBPs within a small group. One MBP (orange contours) is pushed by the granules past the small group, before being forced back and eventually merging with another MBP (green contour). The merger results in a peak in the LOS magnetic field. The granules continue to buffet the newly merged MBP compressing it, and resulting in the secondary peak a couple of seconds after the merger peak. The comparison between NICOLE and SIR in panels b and c confirm the amplification due to these processes.