Sequence of SOT/NFI Hα images. The colour bar applies to all plots and the xy axes indicate the size of each image. The contour lines in the 3rd frame of the top row enclose kG magnetic fields at log (τ) = −0.8 obtained from the inversion of a SOT/SP scan. The grey contour lines in the third panel of the top row correspond to negative polarity and the magenta to positive polarity fields. The three white boxes are identical to those in Fig. 1.