Solar surface emerging flux regions: a comparative study of radiative MHD modeling and Hinode SOT observations

TL;DR

This study compares 3D radiative MHD simulations of solar flux emergence with Hinode SOT observations, revealing detailed dynamics of magnetic flux tubes and their surface manifestations.

Contribution

It provides a comprehensive comparison between numerical models and observations, enhancing understanding of flux emergence processes on the solar surface.

Findings

Magnetic flux tubes expand laterally into sheets during rise

Serpentine field lines emerge due to convective interactions

Observed flux cancellation and high-speed downflows are explained

Abstract

We present results from numerical modeling of emerging flux regions on the solar surface. The modeling was carried out by means of 3D radiative MHD simulations of the rise of buoyant magnetic flux tubes through the convection zone and into the photosphere. Due to the strong stratification of the convection zone, the rise results in a lateral expansion of the tube into a magnetic sheet, which acts as a reservoir for small-scale flux emergence events at the scale of granulation. The interaction of the convective downflows and the rising magnetic flux undulates it to form serpentine field lines emerging into the photosphere. Observational characteristics including the pattern of emerging flux regions, the cancellation of surface flux and associated high speed downflows, the convective collapse of photospheric flux tubes, the appearance of anomalous darkenings, the formation of bright points and the possible existence of transient kilogauss horizontal fields are discussed in the context of new observations from the Hinode Solar Optical Telescope. Implications for the local helioseismology of emerging flux regions are also discussed.