Plasma Physics Seminar (Phys 769)

Dr. Dana Longcope, Montana State University
Quantifying Magnetic Reconnection in the Solar Corona

Energy release by magnetic reconnection has been hypothesized to drive numerous energetic phenomena in the solar corona, including flares, coronal mass ejections, jets and bright points. Many studies have quantified the energy input into these phenomena and related it to energy conversion in theoretical models of magnetic reconnection. In this way it has proven easier to quantify the effects of magnetic reconnection than to quantify the topological changes which are the direct result of reconnection itself. Direct measurements of topological change have recently been made using the observation of coronal loops forming between an existing active region and a newly emerging one. In this one case, fast reconnection appears to begin only after a 24-hour period of latency. Topological models of realistic, three-dimensional, coronal magnetic fields show the form of the relationship which should exist between topological change and energy release. They do this without modeling the details of the reconnection process whereby parallel electric field is produced. Applying such a model to the old and emerging active regions confirm that reconnection between them could supply the energy for the observed brightening. The required energy would not, however, have been available had fast reconnection occurred without latency.

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