The removal of magnetic flux from the quiet-sun photosphere is important for
maintaining the statistical steady-state of the magnetic field there, for
determining the magnetic flux budget of the Sun, and for estimating the rate of
energy injected into the upper solar atmosphere. Magnetic feature death is a
measurable proxy for the removal of detectable flux. We used the SWAMIS feature
tracking code to understand how nearly 20000 detected magnetic features die in
an hour-long sequence of Hinode/SOT/NFI magnetograms of a region of quiet Sun.
Of the feature deaths that remove visible magnetic flux from the photosphere,
the vast majority do so by a process that merely disperses the
previously-detected flux so that it is too small and too weak to be detected.
The behavior of the ensemble average of these dispersals is not consistent with
a model of simple planar diffusion, suggesting that the dispersal is
constrained by the evolving photospheric velocity field. We introduce the
concept of the partial lifetime of magnetic features, and show that the partial
lifetime due to Cancellation of magnetic flux, 22 h, is 3 times slower than
previous measurements of the flux turnover time. This indicates that prior
feature-based estimates of the flux replacement time may be too short, in
contrast with the tendency for this quantity to decrease as resolution and
instrumentation have improved. This suggests that dispersal of flux to smaller
scales is more important for the replacement of magnetic fields in the quiet
Sun than observed bipolar cancellation. We conclude that processes on spatial
scales smaller than those visible to Hinode dominate the processes of flux
emergence and cancellation, and therefore also the quantity of magnetic flux
that threads the photosphere.