Decoding Three-Dimensional Reconnection Dynamics in Solar Flare Ribbons & Loops Speaker Name: Joel Dahlin, Goddard Space Flight Center
Solar flares are spectacular manifestations of explosive energy release powered by magnetic reconnection. The three-dimensional structure and dynamics of flares are thought to be critical to understanding the nature of this energy release. Of particular interest are coherent magnetic structures known as plasmoids, which are understood to play important roles in facilitating explosive energy release and driving nonthermal particles. Direct measurement of the magnetic fields in the corona where the reconnection occurs is, however, highly challenging. By contrast, `indirect' high-resolution observations of flare loops and ribbons are plentiful and contain critical information regarding the three-dimensional structure. Flare ribbons are chromospheric patches illuminated by particle beams, tracing the footpoints of newly reconnected field lines. Hot and dense plasma evaporated by these beams form `flare loops' that reveal the morphology of the reconnected magnetic field. We present high-resolution, three-dimensional MHD modeling of an eruptive flare and discuss our efforts to understand the reconnection dynamics revealed in these observations. We demonstrate in detail how the evolution of flare ribbon fine structure corresponds to plasmoid birth, propagation, and annihilation. We furthermore show that the geometry (e.g., the tilt) of the flare loops encodes key information about the spatiotemporal evolution of the reconnection guide field. We discuss the implications for understanding reconnection energy release and particle acceleration throughout the universe. |