A Comprehensive Radiative Magnetohydrodynamics Simulation of Active Region Scale Flux Emergence from the Convection Zone to the Corona

Abstract

We present a comprehensive radiative magnetohydrodynamic simulation of the quiet Sun and large solar active regions. The 197 Mm wide simulation domain spans from the uppermost convection zone to over 100 Mm in the solar corona. Sophisticated treatments of radiative transfer and conduction transport provide the necessary realism for synthesizing observables to compare with remote sensing observations of the Sun. This model self-consistently reproduces observed features of the quiet Sun, emerging and developed active regions, and solar flares up to M class. Here, we report an overview on the first results. The surface magnetoconvection yields an upward Poynting flux that is dissipated in the corona and heats the plasma to over one million K. The quiescent corona also presents ubiquitous propagating waves, jets, and bright points with sizes down to 2 Mm. Magnetic flux bundles generated in a solar convective dynamo emerge into the photosphere and gives rise to strong and complex active regions with Over 10 23 Mx magnetic flux. The coronal free magnetic energy, which is about 18% of the total magnetic energy, accumulates to about 10 33 erg. The coronal magnetic field is not forcefree, as the Lorentz force needs to balance the pressure force and viscous stress as well as to drive magnetic field evolution. Emission measure from log 10 T = 4.5 to log 10 T > 7 provides a comprehensive view on structures and dynamics in the active region corona, such as coronal loops in various lengths and temperatures, mass circulation by evaporation and condensation, and eruptions from jets to large-scale mass ejections.

Radiative Magnetohydrodynamic Simulation of the Confined Eruption of a Magnetic Flux Rope: Magnetic Structure and Plasma Thermodynamics

“…Complex active regions are formed in the photosphere and give rise to diverse solar activities including more than 50 flares of C class or above. Comprehensive descriptions on the simulation setup and general results are presented in Chen et al (2021).…”

“…In this Letter, we investigate a flux-rope eruption in an RMHD simulation of an active-region-scale flux emergence from the convection zone to the corona (Chen et al 2021). The simulation provides a comprehensive history of the fully selfconsistent evolution of the magnetic field starting from the interior.…”

Three-dimensional Magnetic and Thermodynamic Structures of Solar Microflares

“…The domain is resolved by 1024 × 1024 × 2048 grid points, corresponding to spatial resolutions of 192 and 64 km in the horizontal and vertical directions, respectively. This simulation is the "QS run" in a comprehensive simulation of magnetic flux emergence from the convection zone to the corona (Chen et al 2021a). More details on the simulation setup and general properties of the coronal plasma and magnetic field are presented in the reference.…”

A Babcock–Leighton-type Solar Dynamo Operating in the Bulk of the Convection Zone

“…Recent MHD simulations of global solar/stellar convection provide a new scenario for the generation of the toroidal flux. Nelson et al (2013Nelson et al ( , 2014 and Chen et al (2021) show that convective simulations without the tachocline spontaneously generate rope-like structures of magnetic flux that rise to the top of the simulation domain in a solar-like manner. Fan & Fang (2014), Guerrero et al (2016), and Käpylä et al (2017) demonstrate that solar-like large-scale magnetic fields can be produced entirely within a convection zone without extending the simulation down to the tachocline.…”