Magnetic fields and the occurrence of flares and microflares are strongly concentrated near that portion (the Hale boundary) in each solar hemisphere where the change in magnetic sector polarity is the same as that between leading and following sunspot polarities in active regions.
@article{arxiv.1010.2710,
title = {Flaring Solar Hale Sector Boundaries},
author = {Leif Svalgaard and Iain G. Hannah},
journal= {arXiv preprint arXiv:1010.2710},
year = {2015}
}