Authors: Tamima Saba (Georgia State University), Viacheslav Sadykov (Georgia State University), Piet Martens (Georgia State University)

Understanding the nature of a flare in terms of its effects on space weather is crucial. A flare event can be eruptive or confined depending on whether it accompanies a Coronal Mass Ejection (CME). Flare ribbons, phenomena occurring at the footpoints of flares in the chromosphere and indicating regions of the chromospheric energy deposit, can reflect the three-dimensional magnetic field topology and, therefore, relate to eruptivity. Based on the Standard Flare Model, it has long been argued that a “two-ribbon flare” would have a higher probability of being eruptive. As a preliminary investigation to understand the relation between a two-ribbon flare and its eruptivity, we selected a sample of fifty M and X class flare events that occurred from May 2010 through April 2016 in solar cycle 24. Classified as “eruptive” or “confined,” adopted from Toriumi 2017, these flares have been mapped using data from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) of the 1600 Å channel. The opinions of three experts have been considered to determine whether the flare ribbon topology for each flare was as expected for a two-ribbon flare. We found that around 52-62% of the sample had a two-ribbon topology, and among these, 68-80% were eruptive. This range of probabilities is larger than the reference eruptivity probability calculated for the catalog (which is 64%). Thus, it can be concluded from this catalog that a two-ribbon flare in the selected sample is more likely to be eruptive. To draw a general conclusion on the relationship between two-ribbon flares and their eruptivity, we extend the study to a bigger sample of 722 C, M, and X class flares between June 2010 and September 2017, and discuss the related outcomes.