MDI magnetograms during flares i, iii, and v. The images are all clipped to the same maximum and minimum of  ± 500 G. The observation times are indicated by the vertical lines in Fig. 9 corresponding to the letters a) to i). Upper row [a), b), c)]: the first panel shows the sunspot before flare i. Panel two was taken during the rising phase of flare i and panel c after the flare SXR peak. Middle row [d), e), f)]: magnetograms before flare iii, during the rising phase of the flare and after. Lower row: [g), h), i)]: magnetograms showing the sunspot this time before flare v, during the rising phase of the flare and again after.