Letter to the Editor

The relation between plasmoids and supra-arcade downflows in solar flares

¹ Institute of Space Physics, Luoyang Normal University, Luoyang 471934, PR China
² Yunnan Key Laboratory of the Solar physics and Space Science, Kunming 650216, PR China
³ Yunnan Observatories, Chinese Academy of Sciences, Kunming 650216, PR China
⁴ College of Physics & Electronic Information, Luoyang Normal University, Luoyang 471934, PR China

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 21 May 2026
Accepted: 9 July 2026

Abstract

Context. Plasmoids and supra-arcade downflows (SADs) are two important structures that facilitate the energy transformation and particle acceleration in regions above solar flare loop tops. The connection between them is unclear, however.

Aims. To determine the counterpart of plasmoids in a face-on perspective and the bridge between plasmoids and SADs, we investigated the thermal-dynamical behaviors of bubble-like SADs (BSADs) in a solar flare.

Methods. We used time-series images and the differential emission measure method to study the performance of BSADs observed on September 1, 2024. To explain these BSADs, we used synthetic face-on images created from the 3D magnetohydrodynamical simulations of solar eruptions.

Results. The sunward movement of BSADs caused the local plasma emission and density along the path to first decrease and then to recover partially. Collisions between BSADs and the upper side of the supra-arcade fan generated distinctive Y-shape plasma morphologies that are spatiotemporally correlated with the initiation of tadpole-like SADs. In simulations, the evolution of regions encircled by twisted tube-like plasmoids was similar to the evolution observed BSADs.

Conclusions. As an intermediary, BSADs not only reflect the dynamical behavior of plasmoids from the face-on perspective, but also perturb the region above flare loop tops to facilitate the formation of tadpole-like SADs. We propose decomposing the emission-depleted structures observed above flare loop tops into the high-altitude BSADs associated with 3D magnetic flux tubes and low-altitude tadpole-like SADs. These findings provide novel insights into energy dissipation processes and the correlations between magnetic structures in solar flares.