Solar Magnetic Carpet III: Coronal Modelling of Synthetic Magnetograms

TL;DR

This study uses 3D time-dependent simulations of synthetic magnetograms to analyze magnetic energy buildup and dissipation in the solar magnetic carpet, providing insights into small-scale solar phenomena and coronal heating.

Contribution

It presents the first detailed coronal modeling of synthetic magnetograms with varying overlying magnetic fields, advancing understanding of energy storage and release in the solar magnetic carpet.

Findings

Free magnetic energy is sufficient for nanoflares and bright points.

Most energy is stored low in the corona, between 0.5-0.8 Mm.

Energy dissipation is currently too small for full coronal heating.

Abstract

This paper is the third in a series of papers working towards the construction of a realistic, evolving, non-linear force-free coronal field model for the solar magnetic carpet. Here, we present preliminary results of 3D time-dependent simulations of the small-scale coronal field of the magnetic carpet. Four simulations are considered, each with the same evolving photospheric boundary condition: a 48 hr time series of synthetic magnetograms produced from the model of Meyer, Mackay, van Ballegooijen and Parnell, 2011, Solar Phys., 272, 29. Three simulations include a uniform, overlying coronal magnetic field of differing strength, the fourth simulation includes no overlying field. The build-up, storage and dissipation of magnetic energy within the simulations is studied. In particular, we study their dependence upon the evolution of the photospheric magnetic field and the strength of the overlying coronal field. We also consider where energy is stored and dissipated within the coronal field. The free magnetic energy built up is found to be more than sufficient to power small-scale, transient phenomena such as nanoflares and X-ray bright points, with the bulk of the free energy found to be stored low down, between 0.5-0.8 Mm. The energy dissipated is presently found to be too small to account for the heating of the entire quiet Sun corona. However, the form and location of energy dissipation regions are in qualitative agreement with what is observed on small scales on the Sun. Future MHD modelling using the same synthetic magnetograms may lead to a higher energy release.