Power-law Statistics of Driven Reconnection in the Magnetically Closed Corona

• Published in: The Astrophysical journal Vol. 853; no. 1; pp. 82 - 95
• Main Authors: Knizhnik, K. J., Uritsky, V. M., Klimchuk, J. A., DeVore, C. R.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 20-01-2018; IOP Publishing
• Subjects: Astrophysics; Braiding; Computer simulation; Corona; Extreme ultraviolet radiation; Fluxes; Hard X-rays; Magnetic reconnection; Mathematical models; Numerical simulations; Photosphere; Power law; Radio waves; Soft x rays; Solar corona; Solar phenomena; Sun: corona; Sun: general; Sun: magnetic fields; Temperature changes; Ultraviolet radiation; X-rays
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/aaa0d9

Numerous observations have revealed that power-law distributions are ubiquitous in energetic solar processes. Hard X-rays, soft X-rays, extreme ultraviolet radiation, and radio waves all display power-law frequency distributions. Since magnetic reconnection is the driving mechanism for many energetic solar phenomena, it is likely that reconnection events themselves display such power-law distributions. In this work, we perform numerical simulations of the solar corona driven by simple convective motions at the photospheric level. Using temperature changes, current distributions, and Poynting fluxes as proxies for heating, we demonstrate that energetic events occurring in our simulation display power-law frequency distributions, with slopes in good agreement with observations. We suggest that the braiding-associated reconnection in the corona can be understood in terms of a self-organized criticality model driven by convective rotational motions similar to those observed at the photosphere.