Effects of Magnetic Perturbation on Reconnection and Heating in the Solar Corona

• Published in: The Astrophysical journal Vol. 903; no. 2; pp. 95 - 109
• Main Authors: Hammoud, Mostafa M., Antar, Ghassan Y., Dayeh, Maher A., Darwish, Marwan S., El Eid, Mounib F.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 01.11.2020; IOP Publishing
• Subjects: Astrophysics; Complex formation; Computational fluid dynamics; Corona; Coronal heating; Driving ability; Evolution; Heating; High temperature; Mach number; Magnetic reconnection; Magnetohydrodynamics; Perturbation; Photosphere; Plasmas (physics); Solar corona; Solar coronal heating; Solar magnetic reconnection; Solar physics
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/abb807

The solar corona exhibits unusually high temperatures (∼106 K) compared to the photosphere (∼5800 K). This coronal heating is one of the fundamental problems in solar physics that has yet to be resolved. Magnetic reconnection is thought to play a critical role in driving this enigmatic heating process. We address the interplay between reconnection in the solar corona and the photospheric footpoint motion. The effect of the latter is modeled to generate an external magnetic perturbation that is added to the main coronal field. Resistive magnetohydrodynamics is used where sources and sinks terms due to the perturbation are explicitly obtained in the equations. We set the perturbation to be sinusoidal in space while remaining time independent. The equations are solved using openFOAM. Our results show that magnetic reconnection with perturbation, even with a very small amplitude, leads to (1) more complex formation and evolution of X-points and plasmoids, (2) a transition from slow to fast reconnection rate, (3) a stronger increase of the temperature, and (4) a quicker formation of high-speed jets driving the hot plasma outside the simulation domain with a Mach number that is six times greater compared to the case without perturbation. Moreover, we also find that a magnetic perturbation with shorter wavelength promotes even a faster temporal evolution of the reconnection process than for the longer wavelength. Therefore, the heating and the dynamics of plasma particles in the solar corona are significantly enhanced when the reconnection process is externally disturbed by even a very small perturbation.