Observationally quantified reconnection providing a viable mechanism for active region coronal heating

TL;DR

This study demonstrates that impulsive magnetic reconnection, driven by observed footpoint motions, can quantitatively explain the heating of the Sun's active region corona, matching EUV observations and emission measures.

Contribution

It provides a quantitative model linking magnetic reconnection driven by measured footpoint velocities to observed coronal heating and EUV emission.

Findings

Reconnection length scale ~160 km.

Model's differential emission measure matches observations.

Synthesized EUV images resemble actual solar images.

Abstract

The heating of the Sun's corona has been explained by several different mechanisms including wave dissipation and magnetic reconnection. While both have been shown capable of supplying the requisite power, neither has been used in a quantitative model of observations fed by measured inputs. Here we show that impulsive reconnection is capable of producing an active region corona agreeing both qualitatively and quantitatively with extreme-ultraviolet observations. We calculate the heating power proportional to the velocity difference between magnetic footpoints and the photospheric plasma, called the non-ideal velocity. The length scale of flux elements reconnected in the corona is found to be around 160 km. The differential emission measure of the model corona agrees with that derived using multi-wavelength images. Synthesized extreme-ultraviolet images resemble observations both in their loop-dominated appearance and their intensity histograms. This work provides compelling evidence that impulsive reconnection events are a viable mechanism for heating the corona.