Layered double diffusive convection: From Earth oceans to giant planet interiors.
Abstract
Many unknowns remain concerning the internal structure and composition of giant gaseous planets. The existence and the properties of an hypothetical central core, in particular, are still debated. Contrary to conventional interior models for giant (exo)planets, we consider an inhomogeneous mixing of heavy elements in the gaseous H/He envelope of these objects. As in the oceans, such compositional gradients can give rise to layered convection which impedes large scale convection, yielding a hotter, super adiabatic interior. As a result, the metal enrichment predicted by this model is up to 30 to 60% larger than previously thought for Jupiter and Saturn. However, metals are preferentially redistributed in the gaseous envelope and coreless models can be found for Jupiter. This inefficient, layered convection, yielding a slower cooling, can help to explain anomalously inflated Hot Jupiters, but also opens a new window on our understanding of giant planet formation and history inside our Solar System.
- Publication:
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SF2A-2012: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics
- Pub Date:
- December 2012
- Bibcode:
- 2012sf2a.conf..237L
- Keywords:
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- Planets and satellites: interiors;
- Convection