Formation of small-scale magnetic elements: surface mechanism

TL;DR

This study uses 2D MHD simulations to explore how surface mechanisms during granule fragmentation can form and intensify small-scale magnetic elements on the Sun, revealing a process for magnetic flux concentration.

Contribution

First simulation demonstrating a surface mechanism for forming small-scale magnetic elements during solar granule fragmentation.

Findings

Surface mechanism forms thin magnetic elements during granule fragmentation.

Magnetogranulation can concentrate magnetic flux at convective cell boundaries.

Formation of nearly vertical magnetic flux tubes from weak horizontal fields.

Abstract

We present the first results of a two-dimensional MHD simulation of the solar magnetogranulation. The medium was assumed to be compressible, gravitationally stratified, radiatively coupled, partially ionized, and turbulent. The simulated magnetogranulation evolved over the course of two hours of hydrodynamic (solar) time. A surface (magnetic plume-like) mechanism which forms thin magnetic elements was found to operate during the process of granule fragmentation. The activity of such a mechanism suggests that the magnetogranulation can concentrate and intensify the global magnetic flux at the boundaries of convective cells and can also form nearly vertical compact magnetic flux tubes by involving the weak horizontal photospheric field, which may be, in general, of local (turbulent) nature.