Dynamic Interaction of Convection with Magnetic Flux Sheets: First Results of a New MHD Code
Methods, tests, and first results of a new code for the simulation of solar magnetoconvection are presented. Special emphasis is laid on a reliable and economic treatment of small-scale structures like magnetic flux concentrations, current layers and shocks in 3-D, time-dependent simulations. The numerical grid is adjusted to the local resolution requirements using the method of Adaptive Mesh Refinement (AMR). We describe the implementation of the AMR technique in an MHD code and show a number of test cases. First results on the interaction of magnetic flux sheets with radiative, non-stationary convection in the solar atmosphere have been obtained with a 2-D version of the code. Besides recovering a number of basic features of previous models for such structures, we find a spectacular new phenomenon: strong bending of a flux sheet by asymmetric convective flow followed by rapid sweeping back due to buoyancy and magnetic tension. Such events may lead to the excitation of transversal MHD waves and therefore possibly contribute to heating the upper solar atmosphere.
Key wordssolar magnetic fields convection magnetoconvection magnetic flux tubes numerical methods MHD
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