Energy Cascades in Large-Scale Solar Flare Reconnection
Very fast energy release is sometimes observed in large-scale current layers formed in astrophysical plasmas. Solar flares represent a clear example. The dissipation and changes of the magnetic field topology in the almost collision-less plasmas are inherently related to plasma-kinetic processes in very thin current sheets (CSs). Question arises, how the originally thick current layer is efficiently fragmented into these small-scale dissipative CSs. We investigated this question by means of high-resolution MHD simulations. In addition to the earlier considered chain plasmoid instability we identified other elementary process for energy transport from large to small scales – fragmenting coalescence of plasmoids. This result changes so far basically 1D picture of energy cascade in a large scale magnetic reconnection and reveals multi-dimensional nature of the fragmentation process. At the same moment it shows that plasmoid coalescence contributes – quite surprisingly – to the direct energy cascade.
KeywordsSolar Flare Magnetic Reconnection Current Layer Astrophysical Plasma Anomalous Resistivity
This research was supported by the grants P209/12/0103 (GA CR), P209/10/1680 (GA CR), 5322215000801 (IGA UJEP) and the research project AV0Z10030501 of the Astronomical Institute of the Academy of Sciences.
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