Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Modeling the Longitudinal Asymmetry in Sunspot Emergence -- the Role of
  the Wilson Depression   The distributions of sunspot longitude at first appearance and at
disappearance display an east-west asymmetry that results from a reduction in
visibility as one moves from disk centre to the limb. To first order, this is
explicable in terms of simple geometrical foreshortening. However, the
centre-to-limb visibility variation is much larger than that predicted by
foreshortening. Sunspot visibility is also known to be affected by the Wilson
effect: the apparent dish shape of the sunspot photosphere caused by the
temperature-dependent variation of the geometrical position of the tau=1 layer.
In this article we investigate the role of the Wilson effect on the sunspot
appearance distributions, deducing a mean depth for the umbral tau=1 layer of
500 to 1500 km. This is based on the comparison of observations of sunspot
longitude distribution and Monte Carlo simulations of sunspot appearance using
different models for spot growth rate, growth time and depth of Wilson
depression.

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The categories of this paper are: adap-org
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The categories of this paper are: solv-int
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg
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The categories of this paper are: cs
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The categories of this paper are: hep-ex
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The categories of this paper are: alg-geom
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The categories of this paper are: nlin
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The categories of this paper are: chem-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: math
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph