SDO/AIA and Hinode/EIS Observations of Interaction Between an EUV Wave and Active Region Loops

TL;DR

This study analyzes an EUV wave's interaction with active region loops and coronal structures, revealing wave-induced perturbations, reflections, and dynamics consistent with a fast-mode magnetosonic wave driven by an expanding CME.

Contribution

It provides detailed observational evidence of EUV wave interactions with active region loops and coronal features, supporting the fast-mode magnetosonic wave model.

Findings

EUV wave propagated at 430-910 km/s.

Wave caused measurable Doppler shifts in AR loops.

Reflected waves and secondary wave generation observed.

Abstract

We present detailed analysis of an extreme ultraviolet (EUV) wave and its interaction with active region (AR) loops observed by the Solar Dynamics Observatory/Atmospheric Imaging Assembly and the Hinode EUV Imaging Spectrometer (EIS). This wave was initiated from AR 11261 on 2011 August 4 and propagated at velocities of 430--910 km\s. It was observed to traverse another AR and cross over a filament channel on its path. The EUV wave perturbed neighboring AR loops and excited a disturbance that propagated toward the footpoints of these loops. EIS observations of AR loops revealed that at the time of the wave transit, the original redshift increased by about 3 km\s, while the original blueshift decreased slightly. After the wave transit, these changes were reversed. When the EUV wave arrived at the boundary of a polar coronal hole, two reflected waves were successively produced and part of them propagated above the solar limb. The first reflected wave above the solar limb encountered a large-scale loop system on its path, and a secondary wave rapidly emerged 144 Mm ahead of it at a higher speed. These findings can be explained in the framework of a fast-mode magnetosonic wave interpretation for EUV waves, in which observed EUV waves are generated by expanding coronal mass ejections.