C39

Presentation Title: How significant is the role of turbulent motions in causing flares?
Author(s): A. Sainz Dalda

Abstract:

Turbulent motions have long been associated with flares, but were generally thought to be a result of the energy released by the flare. In a recent study, we analyzed the velocity of turbulent motions in the chromosphere and transition region recovered from the spectral lines observed by IRIS before the X-class flare SOL2014-03-29-17:48 onset. Our findings clearly indicate that the non-thermal velocity (or micro-turbulence) in the flare's ribbon increased about 2 hours before the flare's maximum. This suggests that turbulent motions in the lower atmosphere may play a role in triggering some flares. We discuss possible scenarios that may be consistent with these results.