On the Formation of Active Regions

TL;DR

This study demonstrates that magneto-convection alone can generate active regions on the Sun without the need for pre-existing coherent flux tubes, through detailed simulation of magnetic field evolution.

Contribution

The paper presents a novel simulation showing active region formation from uniform magnetic fields via magneto-convection, without initial flux tubes.

Findings

Magnetic loops of various scales form naturally through convection.

Large loops emerging produce small active regions with characteristic spot configurations.

Active regions can develop solely from convective processes without initial flux tubes.

Abstract

Magneto-convection can produce an active region without an initial coherent flux tube. A simulation was performed where uniform, untwisted, horizontal magnetic field of 1 kG strenght was advected into the bottom of a computational domain 48 Mm wide by 20 Mm deep. The up and down convective motions produce a hierarchy of magnetic loops with a wide range of scales, with smaller loops riding "piggy back" in a serpentine fashion on larger loops. When a large loop approaches the surface it produces an small active region with a compact leading spot and more diffuse following spots.