Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Description of Atmospheric Conditions at the Pierre Auger Observatory
  Using Meteorological Measurements and Models   Atmospheric conditions at the site of a cosmic ray observatory must be known
well for reconstructing observed extensive air showers, especially when
measured using the fluorescence technique. For the Pierre Auger Observatory, a
sophisticated network of atmospheric monitoring devices has been conceived.
Part of this monitoring was a weather balloon program to measure atmospheric
state variables above the Observatory. To use the data in reconstructions of
air showers, monthly models have been constructed. Scheduled balloon launches
were abandoned and replaced with launches triggered by high-energetic air
showers as part of a rapid monitoring system. Currently, the balloon launch
program is halted and atmospheric data from numerical weather prediction models
are used. A description of the balloon measurements, the monthly models as well
as the data from the numerical weather prediction are presented.

31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
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The categories of this paper are: bayes-an
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The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
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The categories of this paper are: eess
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: econ
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The categories of this paper are: alg-geom