Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Meridional Motions and Reynolds Stress Determined by Using
  Kanzelh\"{o}he Drawings and White Light Solar Images from 1964 to 2016   Sunspot position data obtained from Kanzelh\"{o}he Observatory for Solar and
Environmental Research (KSO) sunspot drawings and white light images in the
period 1964 to 2016 were used to calculate the rotational and meridional
velocities of the solar plasma. Velocities were calculated from daily shifts of
sunspot groups and an iterative process of calculation of the differential
rotation profiles was used to discard outliers. We found a differential
rotation profile and meridional motions in agreement with previous studies
using sunspots as tracers and conclude that the quality of the KSO data is
appropriate for analysis of solar velocity patterns. By analysing the
correlation and covariance of meridional velocities and rotation rate residuals
we found that the angular momentum is transported towards the solar equator.
The magnitude and latitudinal dependence of the horizontal component of the
Reynolds stress tensor calculated is sufficient to maintain the observed solar
differential rotation profile. Therefore, our results confirm that the Reynolds
stress is the dominant mechanism responsible for transport of angular momentum
towards the solar equator.

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The categories of this paper are: dg-ga
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The categories of this paper are: cs
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
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The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
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The categories of this paper are: mtrl-th
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The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: math
3
The categories of this paper are: physics
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The categories of this paper are: supr-con