Transport of magnetic flux from the canopy to the internetwork

TL;DR

This paper investigates how magnetic flux from the canopy can be transported downward into the internetwork regions of the Sun using radiative MHD simulations, providing a potential explanation for observed magnetic features embedded in downflows.

Contribution

It introduces a novel flux transport mechanism from the magnetic canopy to the internetwork, supported by radiative MHD simulations, challenging traditional flux emergence models.

Findings

Canopy magnetic fields facilitate flux transport into the internetwork.

Downward plumes associated with convective overshoot carry magnetic flux downward.

This mechanism can explain internetwork linear polarization patches embedded in downflows.

Abstract

Recent observations have revealed that 8% of linear polarization patches in the internetwork quiet Sun are fully embedded in downflows. These are not easily explained with the typical scenarios for the source of internetwork fields which rely on flux emergence from below. We explore using radiative MHD simulations a scenario where magnetic flux is transported from the magnetic canopy overlying the internetwork 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 internetwork with magnetic field. We propose that this mechanism is relevant for the Sun as well, and it could naturally explain the observed internetwork linear polarization patches entirely embedded in downflows.