Transport of magnetic flux from the canopy to the internetwork

Abstract

Recent observations have revealed that 8% of linear polarization patches in the internetwork (INW) quiet Sun are fully embedded in downflows. These are not easily explained with the typical scenarios for the source of INW fields which rely on flux emergence from below. Using radiative MHD simulations, we explore a scenario where magnetic flux is transported from the magnetic canopy overlying the INW into the photosphere by means of downward plumes associated with convective overshoot. We find that if a canopy-like magnetic field is present in the simulation, the transport of flux from the canopy is an important process for seeding the photospheric layers of the INW with magnetic field. We propose that this mechanism is relevant for the Sun as well, and it could naturally explain the observed INW linear polarization patches entirely embedded in downflows. © 2011. The American Astronomical Society. All rights reserved.