Numerical MHD simulations of solar flares and their associated small-scale structures

Abstract

Using numerical simulations, we study the formation and dynamics of post-flare loops in a local region of the solar atmosphere. The MHD equations rule the post-flare structures' dynamic evolution, including space-dependent magnetic resistivity and highly anisotropic thermal conduction on a 2.5 D slice. We use an initial magnetic configuration consisting of a vertical current sheet, which helps trigger the magnetic reconnection process. Specifically, we study two scenarios, one with only resistivity and the second with resistivity plus thermal conduction. Numerical simulations show differences in the global morphology of the post-flare substructures in both cases. In particular, localized resistivity produces more substructure on the loops related to a Ritchmyer-Meshkov Instability (RMI). On the other hand, in the scenario with resistivity plus thermal conduction, the post-flare loops are smooth, and no apparent substructures develop. Besides, in the $z-$component of the current density for the Res+TC scenario, we observe the development of multiple small magnetic islands along the current sheet.

arXiv comment16 pages, 14 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society

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