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| Titel |
Pymiedap: a versatile radiative transfer code with polarization for terrestrial (exo)planets. |
| VerfasserIn |
Loic Rossi, Daphne Stam, Michael Hogenboom |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125170
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| Publikation (Nr.) |
 EGU/EGU2016-4712.pdf |
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| Zusammenfassung |
| Polarimetry promises to be an important method to detect exoplanets: the light
of a star is usually unpolarized\cite{kemp1987} while scattering by gas and
clouds in an atmosphere can generate high levels of polarization. Furthermore,
the polarization of scattered light contains information about the properties
of the atmosphere and surface of a planet, allowing a possible characterization
\cite{stam2008}, a method already validated in the solar system with Venus
\cite{hansen1974,rossi2015}.
We present here Pymiedap (Python Mie Doubling-Adding Program): a set of Python
objects interfaced with Fortran radiative transfer codes that allows to define
a planetary atmosphere and compute the flux and polarization of the light that
is scattered. Several different properties of the planet can be set
interactively by the user through the Python interface such as gravity,
distance to the star, surface properties, atmospheric layers, gaseous and
aerosol composition. The radiative transfer calculations are then computed
following the doubling-adding method \cite{deHaan1987}.
We present some results of the code and show its possible use for different
planetary atmospheres for both resolved and disk-integrated measurements. We
investigate the effect of gas, clouds and aerosols composition and surface
properties for horizontally homogeneous and inhomogenous planets, in the case
of Earth-like planets. We also study the effect of gaseous absorption on the
flux and polarization as a marker for gaseous abundance and cloud top altitude.
\begin{thebibliography}{2}
\bibitem[1]{kemp1987} Kemp et al. The optical polarization of the sun
measured at a sensitivity of parts in ten million. Nature, 1987, 326,
270-273
\bibitem[2]{stam2008} Stam, D. M. Spectropolarimetric signatures of
Earth-like extrasolar planets. A&A, 2008, 482, 989-1007
\bibitem[3]{hansen1974} Hansen, J. E. & Hovenier, J. W. Interpretation of
the polarization of Venus. Journal of Atmospheric Sciences, 1974, 31,
1137-1160
\bibitem[4]{rossi2015} Rossi et al. Preliminary study of Venus cloud
layers with polarimetric data from SPICAV/VEx. Planetary and Space
Science , 2015, 113--114, 159 - 168
\bibitem[5]{deHaan1987} de Haan et al. The adding method for multiple
scattering calculations of polarized light. A&A, 1987, 183, 371-391
\end{thebibliography} |
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