  We investigate the origin of ten solar quiet region pre-jet minifilaments,
using EUV images from SDO/AIA and magnetograms from SDO/HMI. We recently found
panesar16b that quiet region coronal jets are driven by minifilament eruptions,
where those eruptions result from flux cancelation at the magnetic neutral line
under the minifilament. Here, we study the longer-term origin of the pre-jet
minifilaments themselves. We find that they result from flux cancelation
between minority-polarity and majority-polarity flux patches. In each of ten
pre-jet regions, we find that opposite-polarity patches of magnetic flux
converge and cancel, with a flux reduction of 10--40% from before to after the
minifilament appears. For our ten events, the minifilaments exist for periods
ranging from 1.5 hr to two days before erupting to make a jet. Apparently, the
flux cancelation builds highly sheared field that runs above and traces the
neutral line, and the cool-transition-region-plasma minifilament forms in this
field and is suspended in it. We infer that the convergence of the
opposite-polarity patches results in reconnection in the low corona that builds
a magnetic arcade enveloping the minifilament in its core, and that the
continuing flux cancelation at the neutral line finally destabilizes the
minifilament field so that it erupts and drives the production of a coronal
jet. Thus our observations strongly support that quiet region magnetic flux
cancelation results in both the formation of the pre-jet minifilament and its
jet-driving eruption.
