Ubiquitous rotating network magnetic fields and EUV cyclones in the quiet Sun

TL;DR

This study reports the widespread presence of rotating magnetic fields and associated EUV cyclones in the quiet Sun, suggesting a potential mechanism for coronal heating through small-scale magnetic activities.

Contribution

It provides the first comprehensive observational evidence of ubiquitous rotating network magnetic fields and their link to EUV cyclones in the quiet Sun.

Findings

388 RNFs identified in a quiet Sun area of 800x980 arcseconds

RNFs have a magnetic flux of about 4.0×10^{21} Mx, constituting 78% of the total network flux

EUV cyclones last several to over ten hours and are associated with microflares and EUV waves

Abstract

We present the {\it Solar Dynamics Observatory} (SDO) Atmospheric Imaging Assembly (AIA) observations of EUV cyclones in the quiet Sun. These cyclones are rooted in the Rotating Network magnetic Fields (RNFs). Such cyclones can last several to more than ten hours, and, at the later phase, they are found to be associated with EUV brightenings (microflares) and even EUV waves. SDO Helioseismic and Magnetic Imager (HMI) observations show an ubiquitous presence of the RNFs. Using HMI line-of-sight magnetograms on 2010 July 8, we find 388 RNFs in an area of 800$\times$980 square arcseconds near the disk center where no active region is present. The sense of rotation shows a weak hemisphere preference. The unsigned magnetic flux of the RNFs is about 4.0$\times10^{21}$ Mx, or 78% of the total network flux. These observational phenomena at small scale reported in this letter are consistent with those at large scale in active regions. The ubiquitous RNFs and EUV cyclones over the quiet Sun may suggest an effective way to heat the corona.