Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Statistical properties of coronal hole rotation rates: Are they linked
  to the solar interior?   The present paper discusses results of a statistical study of the
characteristics of coronal hole (CH) rotation in order to find connections to
the internal rotation of the Sun. The goal is to measure CH rotation rates and
study their distribution over latitude and their area sizes. In addition, the
CH rotation rates are compared with the solar photospheric and inner layer
rotational profiles. We study coronal holes observed within $\pm 60$ latitude
and longitude degrees from the solar disc centre during the time span from the
1 January 2013 to 20 April 2015, which includes the extended peak of solar
cycle 24.We used data created by the Spatial Possibilistic Clustering Algorithm
(SPoCA), which provides the exact location and characterisation of solar
coronal holes using SDO=AIA 193 {\AA} channel images. The CH rotation rates are
measured with four-hour cadence data to track variable positions of the CH
geometric centre. North-south asymmetry was found in the distribution of
coronal holes: about 60 percent were observed in the northern hemisphere and 40
percent were observed in the southern hemisphere. The smallest and largest CHs
were present only at high latitudes. The average sidereal rotation rate for 540
examined CHs is $13:86 (\pm 0:05)$ degrees/d. Conclusions. The latitudinal
characteristics of CH rotation do not match any known photospheric rotation
profile. The CH angular velocities exceed the photospheric angular velocities
at latitudes higher than 35-40 degrees. According to our results, the CH
rotation profile perfectly coincides with tachocline and the lower layers of
convection zone at around 0.71 $R_{\odot}$; this indicates that CHs may be
linked to the solar global magnetic field, which originates in the tachocline
region.

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The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph