Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Atmospheric dynamics of temperate sub-Neptunes. Part I: dry dynamics   Sub-Neptunes (planets with radii between 2 and 4 R$_{\oplus}$) are abundant
around M-dwarf stars, yet the atmospheric dynamics of these planets is
relatively unexplored. In this paper, we aim to provide a basic underpinning of
the dry dynamics of general low mean molecular weight, temperate sub-Neptune
atmospheres. We use the ExoFMS GCM with an idealised grey gas radiation scheme
to simulate planetary atmospheres with different levels of instellation and
rotation rates, using the atmosphere of K2-18b as our control. We find that the
atmospheres of tidally-locked, temperate sub-Neptunes have weak horizontal
temperature gradients owing to their slow rotation rates and hydrogen-dominated
composition. The zonal wind structure is dominated by high-latitude
cyclostrophic jets driven by the conservation of angular momentum. At low
pressures we observe superrotating equatorial jets, which we propose are driven
by a Rossby-Kelvin instability similar to the type seen in simulations of
idealised atmospheres with axisymmetric forcing. By viewing the flow in
tidally-locked coordinates, we find the predominant overturning circulation to
be between the dayside and nightside, and we derive scaling relations linking
the tidally-locked streamfunction and vertical velocities to instellation.
Comparing our results to the only other GCM study of K2-18b, we find
significant qualitative differences in dynamics, highlighting the need for
further collaboration and investigation into effects of different dynamical
cores and physical parameterizations. This paper provides a baseline for
studying the dry dynamics of temperate sub-Neptunes, which will be built on in
part II with the introduction of moist effects.

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The categories of this paper are: nlin
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The categories of this paper are: econ
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The categories of this paper are: mtrl-th
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The categories of this paper are: nucl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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The categories of this paper are: eess
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The categories of this paper are: chem-ph
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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: atom-ph
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys
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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg