Description
The short timescale of the solar flare reconnection process has long proved to be a puzzle. Studies suggest the importance of the formation of plasmoids in the reconnecting current sheet, with quantifying the aspect ratio of the width to length of the current sheet in terms of a negative power $\alpha$ of the Lundquist number, that is, S$^{-\alpha}$, being key to understanding the onset of plasmoids formation. In this talk, we present our application (the first of its kind) of theoretical scalings for this aspect ratio to observed flares. By doing this we are able to evaluate how plasmoid formation may connect with observations. For three different flares that show plasmoids we find a range of values of $\alpha$=0.26 to 0.31. This is close to the theoretically predicted value, but due to the presence of α in the exponent of the power-law, these differences are somewhat difficult to reconcile. The values in this small range implies that plasmoids may be forming before the theoretically predicted critical aspect ratio ($\alpha=1/3$) has been reached, potentially presenting a challenge for the theoretical models. We will discuss the implications for understanding flare reconnection and how to potentially reconcile these differences.
