Propagating Disturbances in The Solar Corona and Spicular Connection

TL;DR

This study uses coordinated IRIS and AIA observations to show that spicules and propagating disturbances in the solar corona likely originate from common reconnection processes, revealing their quasi-periodic relationship and shared origin.

Contribution

It demonstrates that spicules and coronal propagating disturbances are linked through a common reconnection-driven process, supported by simultaneous multi-instrument observations.

Findings

Spicules and PDs start nearly simultaneously.

Brightenings occur during spicule fallback.

Spicules and PDs share a common origin.

Abstract

Spicules are small hairy like structures seen at the solar limb mainly at chromospheric and transition region lines. They generally live for 3-10 minutes. We observe these spicules in a south polar region of the Sun with a coordinated observations using the Interface Region Imaging Spectrograph (IRIS) and the Atmospheric Imaging Assembly (AIA) instruments on board the Solar Dynamics Observatory. Propagating disturbances (PDs) are observed everywhere in the polar off-limb regions of the Sun at coronal heights. From this simultaneous observations we show that the spicules and the PDs may be originated by a common process. From space-time maps we find that the start of the trajectory of PDs is almost co-temporal with the time of the rise of the spicular envelope as seen by IRIS slit-jaw images at 2796 {\deg}A and 1400 A{\deg} . During the return of spicular material, brightenings are seen in AIA 171 {\deg}A and 193 {\deg}A images. The quasi-periodic nature of the spicular activity as revealed by the IRIS spectral image sequences and its relation to coronal PDs as recorded by the coronal AIA channels suggest that they have a common origin. We propose that reconnection like processes generate the spicules and waves simultaneously. The waves escape while the cool spicular material falls back