Extreme Ultraviolet Microflashes at Plume Bases: A Candidate for Powering the Corona and Solar Wind?

This is the authors' abstract. We don't add key points for this paper.

Solar plumes—outflows of bright coronal plasma—are a major component of the open-magnetic-field corona and solar wind, but their driving mechanism remains uncertain. Here, we report on network microflashes, fine-scale bright bursts captured by Solar Orbiter’s Extreme Ultraviolet Imager in 174 Å images encompassing magnetic network at the base of plumes. Because they sit in evidently unipolar magnetic flux, they are evidently a new, previously unidentified, kind of network event. Approximately 20 microflashes are ongoing within a plume base, with a new microflash starting every second. The energy for an average microflash is ∼10 24 erg, in the range of nanoflares. A 3D data-driven global magnetohydrodynamic model yields an open magnetic field with fast solar wind for the investigated plumes. From our findings, we suggest that network microflashes result from fine-scale bursts of reconnection of crossed legs of unipolar magnetic field, that the bursts are often triggered by 5 minute p -mode oscillations, and that the bursts are candidates for powering the open-field corona and solar wind. That is, unipolar microflashes such as ours are plausibly from unipolar-network-field reconnection bursts that sustain the heliosphere.