(a) AIA 1600 Å image showing the two flare ribbons in its rising phase. HMI intensity images (b1) before and (b2) after the flare, and (c) their difference image showing the disappeared/enhanced penumbra indicated by the black/white arrows. The black/white boxes, “D”/“E,” mark the main decayed/darkened areas. HMI vector magnetograms (d1) before and (d2) after the flare showing the corresponding magnetic-field changes. The vertical components, ﹩{B}_{r}﹩, are shown by black/white isogauss contours for positive/negative polarities over the grayscale background. The contour levels are ±500, 1000, and 1500 G. The horizontal components, ﹩{{\boldsymbol{B}}}_{h}﹩, are denoted by the short arrows aligned to the field direction with color indicating the field strength (see the color bar). The pre-flare main PIL is superposed as the dashed orange curves, and the FOV is 50″ × 50″.

(An animation of this figure is available.)

The video/animation of this figure is available in the online journal.