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arXiv · 1501.01699

Modeling sunspot and starspot decay by turbulent erosion

Yuri E. Litvinenko·M. S. Wheatland
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Abstract

Disintegration of sunspots (and starspots) by fluxtube erosion, originally proposed by Simon and Leighton, is considered. A moving boundary problem is formulated for a nonlinear diffusion equation that describes the sunspot magnetic field profile. Explicit expressions for the sunspot decay rate and lifetime by turbulent erosion are derived analytically and verified numerically. A parabolic decay law for the sunspot area is obtained. For moderate sunspot magnetic field strengths, the predicted decay rate agrees with the results obtained by Petrovay and Moreno-Insertis. The new analytical and numerical solutions significantly improve the quantitative description of sunspot and starspot decay by turbulent erosion.

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Yuri E. Litvinenko, M. S. Wheatland. 2015-01-08. Modeling sunspot and starspot decay by turbulent erosion. https://doi.org/10.1088/0004-637x%2F800%2F2%2F130

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