3D MHD modeling of twisted coronal loops

Abstract

We perform MHD modeling of a single bright coronal loop to include the interaction with a non-uniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated into heating by growing currents through anomalous magnetic diffusivity that switches on in the corona above a current density threshold. We model an entire single magnetic flux tube, in the solar atmosphere extending from the high-beta chromosphere to the low-beta corona through the steep transition region. The magnetic field expands from the chromosphere to the corona. The maximum resolution is ~30 km. We obtain an overall evolution typical of loop models and realistic loop emission in the EUV and X-ray bands. The plasma confined in the flux tube is heated to active region temperatures (~3 MK) after ~2/3 hr. Upflows from the chromosphere up to ~100 km/s fill the core of the flux tube to densities above 10^9 cm^-3. More heating is released in the low corona than the high corona and is finely structured both in space and time.

29 pages, 14 figures, accepted for publication, movies available upon request to the first author

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• Modeling Coronal Response in Decaying Active Regions with Magnetic Flux Transport and Steady Heating
• A comparison study of extrapolation models and empirical relations in forecasting solar wind
• Helical Twisting Number and Braiding Linkage Number of Solar Coronal Loops
• Laboratory evidence for asymmetric accretion structure upon slanted matter impact in young stars
• Observational signatures of a kink-unstable coronal flux rope using Hinode/EIS
• Can Multi-Threaded Flux Tubes in Coronal Arcades Support a Magnetohydrodynamic Avalanche?
• A fast multi-dimensional magnetohydrodynamic formulation of the transition region adaptive conduction (TRAC) method