  Penumbrae are the manifestation of magnetoconvection in highly inclined (to
the vertical direction) magnetic field. The penumbra of a sunspot tends to
form, initially, along the arc of the umbra antipodal to the main region of
flux emergence. The question of how highly inclined magnetic field can
concentrate along the antipodal curves of umbrae, at least initially, remains
to be answered. Previous observational studies have suggested the existence of
some form of overlying magnetic canopy which acts as the progenitor for
penumbrae. We propose that such overlying magnetic canopies are a consequence
of how the magnetic field emerges into the atmosphere and are, therefore, part
of the emerging region. We show, through simulations of twisted flux tube
emergence, that canopies of highly inclined magnetic field form preferentially
at the required locations above the photosphere.
