Solar Flux Emergence Simulations

TL;DR

This paper simulates the emergence of magnetic flux from the solar interior, revealing how different field strengths influence convective flows and surface magnetic structures, including pore-like formations.

Contribution

It provides new insights into how magnetic flux of varying strengths rises and interacts with solar convection, producing observable surface features.

Findings

10 kG fields minimally affect convection and rise in 32 hours.

20 and 40 kG fields modify convection and rise faster due to magnetic buoyancy.

Emergence of large-scale magnetic loops leads to pore-like structures.

Abstract

We simulate the rise through the upper convection zone and emergence through the solar surface of initially uniform, untwisted, horizontal magnetic flux with the same entropy as the non-magnetic plasma that is advected into a domain 48 Mm wide from from 20 Mm deep. The magnetic field is advected upward by the diverging upflows and pulled down in the downdrafts, which produces a hierarchy of loop like structures of increasingly smaller scale as the surface is approached. There are significant differences between the behavior of fields of 10 kG and 20 or 40 kG strength at 20 Mm depth. The 10 kG fields have little effect on the convective flows and show little magnetic buoyancy effects, reaching the surface in the typical fluid rise time from 20 Mm depth of 32 hours. 20 and 40 kG fields significantly modify the convective flows, leading to long thin cells of ascending fluid aligned with the magnetic field and their magnetic buoyancy makes them rise to the surface faster than the fluid rise time. The 20 kG field produces a large scale magnetic loop that as it emerges through the surface leads to the formation of a bipolar pore-like structure.