Sequence of HMI intensitygrams displaying the shearing motion of the bipolar sunspots. The green and red plus symbols, connected by the green lines, mark the intensity centroids of the sunspots with positive (P) and negative (N) polarities, respectively. The orientation, γ, is defined as varying within the range of [0, 360]°, as is illustrated in the inset circular image in (a). The box in (e) outlines the field of view (FOV) of Fig. 4, and the blue and red curves are the contours of the positive and negative magnetic fields at ±500 G levels. An animation (Movie1.mp4) of this figure is available online.