A Multi-Wavelength Statistical Study of Supra-Arcade Downflows

TL;DR

This study analyzes supra-arcade downflows (SADs) using multi-wavelength data from various solar observatories, providing detailed measurements of their properties to inform reconnection models.

Contribution

It introduces a semi-automatic detection method applied to a large flare sample, estimating SAD parameters and comparing them with shrinking loop observations.

Findings

SADs have characteristic speeds, sizes, and magnetic flux consistent with reconnection outflows.

Measurements suggest a relationship between SAD dynamics and magnetic reconnection processes.

Comparison with shrinking loops offers insights into the reconnection energy release.

Abstract

Sunward-flowing voids above post-coronal mass ejection flare arcades, also known as supra-arcade downflows (SADs), have characteristics consistent with post-reconnection magnetic flux tube cross-sections. Applying semi-automatic detection and analysis software to a large sample of flares using several instruments (e.g., Hinode/XRT, Yohkoh/SXT, TRACE, and SOHO/LASCO), we have estimated parameters such as speeds, sizes, heights, magnetic flux, and relaxation energy associated with SADs, which we interpret as reconnection outflows. We also present speed and height measurements of shrinking loops in comparison to the SAD observations. We briefly discuss these measurements and what impact they have on reconnection models.