Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Saturn's Polar Atmosphere   This book chapter, Saturn's Polar Atmosphere, is to be published by Cambridge
University Press as part of a multi-volume work edited by Kevin Baines, Michael
Flasar, Norbert Krupp, and Thomas Stallard, entitled "Saturn in the 21st
Century." This chapter reviews the state of our knowledge about Saturn's polar
atmosphere that has been revealed through Earth- and space-based observation as
well as theoretical and numerical modeling. In particular, the Cassini mission
to Saturn, which has been in orbit around the ringed planet since 2004, has
revolutionized our understanding of the planet. The current review updates a
previous review by Del Genio et al (2009; Saturn Atmospheric Structure and
Dynamics, Chapter 7 of "Saturn from Cassini-Huygens"), written after Cassini's
primary mission phase that ended in 2008, by focusing on the north polar region
of Saturn and comparing it to the southern high latitudes. Two prominent
features in the northern high latitudes are the northern hexagon and the north
polar vortex; we extensively review observational and theoretical
investigations to date of both features. We also review the seasonal evolution
of the polar regions using the observational data accumulated during the
Cassini mission since 2004 (shortly after the northern winter solstice in
2002), through the equinox in 2009, and approaching the next solstice in 2017.
We conclude the current review by listing unanswered questions and describing
the observations of the polar regions planned for the Grand Finale phase of the
Cassini mission between 2016 and 2017.

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The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
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The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph