Spatially intermittent fields in photospheric magnetoconvection |
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| Authors: | P J Bushby S M Houghton |
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| Institution: | Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA |
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| Abstract: | Motivated by recent high-resolution observations of the solar surface, we investigate the problem of non-linear magnetoconvection in a three-dimensional compressible layer. We present results from a set of numerical simulations which model the situation in which there is a weak imposed magnetic field. This weak-field regime is characterized by vigorous granular convection and spatially intermittent magnetic field structures. When the imposed field is very weak, magnetic flux tends to accumulate at the edges of the convective cells, where it forms compact, almost 'point-like' structures which are reminiscent of those observed in the quiet Sun. If the imposed field is slightly stronger, there is a tendency for magnetic flux to become concentrated into 'ribbon-like' structures which are comparable to those observed in solar plages. The dependence of these simulations upon the strength of the imposed magnetic field is analysed in detail, and the concept of the fractal dimension is used to make a further, more quantitative comparison between these simulations and photospheric observations. |
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| Keywords: | convection MHD Sun: granulation Sun: magnetic fields Sun: photosphere |
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