| Presentation Title: | Decoding Three-Dimensional Reconnection Dynamics in Flare Ribbons |
| Author(s): | J. T. Dahlin, J. Qiu, S. K. Antiochos, C. R. DeVore, P. F. Wyper |
Abstract:
Solar flares are spectacular manifestations of explosive energy release powered by magnetic reconnection. While the standard CSHKP model has proven highly successful in explaining key features of flare observations in terms of magnetic reconnection, many aspects of the energy release are not yet understood. In particular, the complex three-dimensional structure of the flare current sheet is thought to play important roles in particle acceleration and bursty energy release. While direct diagnosis of the magnetic field dynamics in the corona is highly challenging, rich information may nevertheless be gleaned from flare ribbons, which represent the chromospheric imprints of reconnection in the corona. In particular, high-resolution observations by IRIS and BBSO/GST have revealed that ribbons frequently exhibit plentiful fine structure that hints at corresponding structures in the reconnection region - e.g., plasmoids or turbulence.
We present high-resolution MHD modeling of an eruptive flare and discuss our efforts to interpret flare ribbon features in terms of associated reconnection dynamics. We focus on field-line length maps which we employ to identify analogues of chromospheric transient brightenings associated with reconnection. Our model analogues of ribbon brightenings exhibit numerous fine-scale ‘spirals’. We show in detail how the evolution of the flare-ribbon spirals reveal the birth, propagation, and annihilation of coronal plasmoids formed in the flare current sheet. We show in detail how the evolution of fine-scale flare ribbon spirals reveal the birth, propagation, and annihilation of plasmoids. We discuss implications for interpretation of flare ribbon observations.