Cradle-to-Grave Evolution and Explosiveness of the Magnetic Field from Bipolar Ephemeral Active Regions (BEARs) in Solar Coronal Holes

We report on the magnetic evolution of magnetic-explosion eruption production of each of seven BEARs observed in on-disk coronal holes in line-of-sight magnetograms and in coronal EUV images. One of these BEARs produced no eruptions. The other six BEARs display three kinds of magnetic-explosion eruptions: (1) blowout eruptions, (2) partially-confined eruptions, (3) confined eruptions. The seven BEARs are a subset of 60 random coronal-hole BEARs, with visually estimated emergence phases. In this work, we obtain a reliable determination of when the emergence phase ended by finding the time of the BEAR’s maximum minority flux from a time plot. These plots show: (1) none of the seven BEARs had an inside eruption while the BEAR was emerging, and (2) for these seven BEARs, the visually-estimated emergence end time was never more than six hours before the measured time of maximum minority flux. Our findings support that a great majority of the explosive magnetic fields from BEARs in coronal holes are prepared and triggered to explode by magnetic flux cancellation, and that such flux cancellation seldom occurs inside an emerging BEAR.