On the correlation between the orientation of moving magnetic features and the large-scale twist of sunspots

We present new results on the nature of moving magnetic features (MMFs) deduced from Big Bear Solar Observatory observations of the longitudinal magnetic fields of two large solar spots. MMFs are small magnetic bipoles that move outward across the moat of an eroding sunspot. We find that MMFs are not randomly oriented. To wit, in 21 out of 28 (75%) MMF pairs, the magnetic element having the polarity of the sunspot was located farther from the sunspot. Furthermore, there is a correlation between the orientation of the bipole and that of the twist in a sunspot. For the two nearly round sunpots we studied, we found that the bipoles were rotated counterclockwise in the case of a clockwise twisted sunspot and clockwise for a spot with counterclockwise twist. We also found a correlation between the orientation of MMF bipole and the amount of twist in the spot. The MMF bipoles around the highly twisted sunspot are oriented nearly tangential to the edge of the sunspot, while in the slightly twisted sunspot the bipoles are oriented nearly radially so that they point back to the spot.