  Coronal plumes are bright magnetic funnels found in quiet regions (QRs) and
coronal holes (CHs). They extend high into the solar corona and last from hours
to days. The heating processes of plumes involve dynamics of the magnetic field
at their base, but the processes themselves remain mysterious. Recent
observations suggest that plume heating is a consequence of magnetic flux
cancellation and/or convergence at the plume base. These studies suggest that
the base flux in plumes is of mixed polarity, either obvious or hidden in SDO
HMI data, but do not quantify it. To investigate the magnetic origins of plume
heating, we select ten unipolar network flux concentrations, four in CHs, four
in QRs, and two that do not form a plume, and track plume luminosity in SDO AIA
171 A images along with the base flux in SDO HMI magnetograms, over each flux
concentrations lifetime. We find that plume heating is triggered when
convergence of the base flux surpasses a field strength of 200 to 600 G. The
luminosity of both QR and CH plumes respond similarly to the field in the plume
base, suggesting that the two have a common formation mechanism. Our examples
of non-plume-forming flux concentrations, reaching field strengths of 200 G for
a similar number of pixels as for a couple of our plumes, suggest that a
critical field might be necessary to form a plume but is not sufficient for it,
thus, advocating for other mechanisms, e.g. flux cancellation due to hidden
opposite-polarity field, at play.
