Observation of High-speed Outflow on Plume-like Structures of the Quiet Sun and Coronal Holes with SDO/AIA

TL;DR

This study uses SDO/AIA observations to reveal widespread high-speed outflows in plume-like structures across the quiet Sun and coronal holes, suggesting a key role in solar wind mass supply and impacting spectroscopic measurements.

Contribution

It provides the first comprehensive observation of high-speed outflows in both plume and inter-plume regions of the quiet Sun and coronal holes, highlighting their potential role in solar wind dynamics.

Findings

High-speed outflows (~120 km/s) are ubiquitous in plume-like structures.

Outflows are present in quiet Sun, equatorial, and polar coronal holes.

Plume flows can significantly affect spectroscopic Doppler shift measurements.

Abstract

Observations from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) reveal ubiquitous episodic outflows (jets) with an average speed around 120 km s-1 at temperatures often exceeding a million degree in plume-like structures, rooted in magnetized regions of the quiet solar atmosphere. These outflows are not restricted to the well-known plumes visible in polar coronal holes, but are also present in plume-like structures originating from equatorial coronal holes and quiet-Sun regions. Outflows are also visible in the "interplume" regions throughout the atmosphere. Furthermore, the structures traced out by these flows in both plume and inter-plume regions continually exhibit transverse (Alfvenic) motion. Our finding suggests that high-speed outflows originate mainly from the magnetic network of the quiet Sun and coronal holes, and that the plume flows observed are highlighted by the denser plasma contained therein. These outflows might be an efficient means to provide heated mass into the corona and serve as an important source of mass supply to the solar wind. We demonstrate that the quiet-Sun plume flows can sometimes significantly contaminate the spectroscopic observations of the adjacent coronal holes - greatly affecting the Doppler shifts observed, thus potentially impacting significant investigations of such regions.