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| Titel |
ÉmerGéantes: a new Global Climate Model to study the dynamics of Saturn's stratosphere - and beyond |
| VerfasserIn |
Aymeric Spiga, Sandrine Guerlet, Melody Sylvestre, Thierry Fouchet |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250084024
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| Zusammenfassung |
| Recent observational programs, both spatial and ground-based, have revealed the complexity
of the middle atmospheres of giant planets. In particular, maps of the temperature and of the
distribution of trace species in the Saturn stratosphere have been obtained by the Cassini
spacecraft with unprecedented details. These maps exhibit puzzling anomalies, which cannot
be explained by current photochemical and radiative models (none of them includes
dynamics), and which have been interpreted as the signature of large-scale or seasonal
dynamical motions. Yet Saturn’s global circulation remains weakly characterized.
Furthermore, on Saturn and Jupiter, equatorial oscillations in the zonal wind and
temperature field have recently been discovered and are reminiscent of the Earth’s
Quasi-Biennial Oscillation, a fundamental dynamical phenomenon. These oscillations
thus appear to be a common dynamical phenomenon in very different planetary
atmospheres.
We will present the development of “ÉmerGéantes”, a new global climate model for giant
planets. This new model is based on the LMDz dynamical core, which has been successfully
adapted to terrestrial planets and moons: the Earth, Mars, Venus, Titan, Triton/Pluton. Details
on the numerical challenges, the adaptations needed to simulate gas giants, and the
optimization of the radiative transfer computations will be presented, along with preliminary
results.
The aim of this project is study in detail the atmospheric circulation of giant planets by
resolving atmospheric circulations in their stratosphere (and, possibly, in the future, the
coupling between their troposphere and stratosphere). It will serve as a new tool to address
fundamental questions in geophysical fluid dynamics, explore the giant planets circulation
patterns, and better interpret current and future observations. This new GCM will first be
focused on reproducing Saturn’s climate, following the harvest of observations obtained by
the Cassini mission. We plan to also study Jupiter in the future, both in the frame of future
missions (Juno, JUICE) and a comparative planetology approach with Saturn. Another area
of fruitful application of our model is extrasolar planets, such as “ hot Jupiters ”, that act as
natural laboratories to broaden our knowledge of atmospheric dynamics in extreme
environments. |
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