Department of Astronomy 2024-2025 Colloquium Series presents:

"Understanding Solar Flare Magnetic Reconnection Dynamics and X-Ray Emission Variability through Flare Ribbons Observations"

In the standard solar flare model flare ribbons are the locations in which flare energy deposits in the footpoints of newly reconnected flare magnetic loops. This talk will address 2 recent projects that use flare ribbon observations to study the dynamics of magnetic reconnection during flares. In the first part of the talk, we will discuss the recent finding of studying 73 flares with co-temporal quasi-periodic pulsations (QPPs) in the reconnected flux rate, estimated from flare ribbon observations, and hard X-ray emission (HXR). The second part of the talk will focus on recent developments in quantitative tracking flare ribbon substructure, and the diagnostic potential of these substructures. Our result suggests the plasmoid instability as a suitable mechanism to explain the QPPs in the reconnection rate and HXR emission, and the formation of flare ribbon substructure due to current sheet fragmentation.