Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A non-grey analytical model for irradiated atmospheres. I: Derivation   Context. Semi-grey atmospheric models (with one opacity for the visible and
one opacity for the infrared) are useful to understand the global structure of
irradiated atmospheres, their dynamics and the interior structure and evolution
of planets, brown dwarfs and stars. But when compared to direct numerical
radiative transfer calculations for irradiated exoplanets, these models
systematically overestimate the temperatures at low optical depth,
independently of the opacity parameters. We wish to understand why semi-grey
models fail at low optical depths, and provide a more accurate approximation to
the atmospheric structure by accounting for the variable opacity in the
infrared. Our analytical irradiated non-grey model is found to provide a range
of temperatures that is consistent with that obtained by numerical
calculations. We find that even for slightly non-grey thermal opacities the
temperature structure differs significantly from previous semi-grey models. For
small values of beta (expected when lines are dominant), we find that the
non-grey effects are confined to low-optical depths. However, for beta larger
than 0.5 (appropriate in the presence of bands with a wavelength-dependence
smaller or comparable with the width of the Planck function), we find that the
temperature structure is affected even down to infrared optical depths unity
and deeper as a result of the so-called blanketing effect. The expressions that
we derive may be used to provide a proper functional form for algorithms that
invert the atmospheric properties from spectral information. Because a full
atmospheric structure can be calculated directly, these expressions should be
useful for simulations of the dynamics of these atmospheres and of the thermal
evolution of the planets. Finally, they should be used to test full radiative
transfer models and improve their convergence.

36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
19
The categories of this paper are: eess