Dynamics of on-disk plumes as observed with Interface Region Imaging Spectrograph, Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager

TL;DR

This study investigates how small-scale transient events at the footpoints of solar coronal plumes influence their formation, evolution, and associated wave phenomena, using multi-instrument observations to analyze plasma flows and magnetic activity.

Contribution

It provides new insights into the role of small-scale reconnections and jet-like outflows in sustaining coronal plumes and generating propagating waves, based on high-resolution IRIS and SDO data.

Findings

Quasi-periodic brightenings linked to magnetic flux changes.

Detection of flows and jet-like features at plume footpoints.

Propagation of slow magnetoacoustic waves within plumes.

Abstract

We examine the role of small-scale transients in the formation and evolution of solar coronal plumes. We study the dynamics of plume footpoints seen in the vicinity of a coronal hole using the Atmospheric Imaging Assembly (AIA) images, the Helioseismic and Magnetic Imager (HMI) magnetogram on board the Solar Dynamics Observatory (SDO) and spectroscopic data from the Interface Region Imaging Spectrograph (IRIS). Quasi-periodic brightenings are observed in the base of the plumes and are associated with magnetic flux changes. With the high spectral and spatial resolution of IRIS, we identify the sources of these oscillations and try to understand what role the transients at the foot points can play in sustaining the coronal plumes. IRIS sit and stare observation provide a unique opportunity to study the evolution of foot points of the plumes. We notice enhanced line width, intensity and large deviation from the average Doppler shift in the line profiles at specific instances which indicate the presence of flows at the foot points of plumes. We propose that outflows (jet-like features) as a result of small scale reconnections affect the line profiles. These jet-like features may be also responsible for the generation of propagating disturbances within the plumes which are observed to be propagating to larger distances as recorded from multiple AIA channels. These propagating disturbances can be explained in terms of slow magnetoacoustic waves.