A new vision of giant planet interiors: Impact of double diffusive convection

By J. Leconte, G. Chabrier. 2012

231 citations recorded by the source corpus.

While conventional interior models for Jupiter and Saturn are based on the simplistic assumption of a solid core surrounded by a homogeneous gaseous envelope, we have derived new models with an inhomogeneous distribution of heavy elements within these planets. Such a compositional gradient hampers large-scale convection that turns into double-diffusive convection, yielding an inner thermal profile that departs from the traditionally assumed adiabatic interior and affecting these planets heat content and cooling history. To address this problem, we have developed an analytical approach to describe layered double-diffusive convection and apply this formalism to solar system gaseous giant planet interiors. These models satisfy all observational constraints and yield values for the metal enrichment of our gaseous giants that are up to 30% to 60% higher than previously thought. The models also constrain the size of the convective layers within the planets. Because the heavy elements tend to be redistributed within the gaseous envelope, the models predict smaller than usual central cores inside Saturn and Jupiter, with possibly no core for the latter. These models open a new window and raise new challenges to our understanding of the internal structure of giant (solar and extrasolar) planets, in particular on how to determine their heavy material content, a key diagnostic for planet formation theories.

Subfields: Astronomy and Astrophysics, Geophysics

View Paper: https://www.semanticscholar.org/paper/ecef4d4b42987b0c6579c229834709ff1d22253b

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Jon Fortney
2. C. Mordasini
3. N. Madhusudhan
4. Th. Henning
5. N. Nettelmann
6. M. Marley
7. Y. Alibert
8. H. Klahr

In Geophysics

1. N. Nettelmann
2. Jon Fortney
3. Ronald Redmer
4. Andreas Becker
5. M. French
6. B. Holst
7. G. Chabrier
8. M. Marley

Citations in the corpus

• A FRAMEWORK FOR CHARACTERIZING THE ATMOSPHERES OF LOW-MASS LOW-DENSITY TRANSITING PLANETS (2013, background): “One should further note that compositional gradients can potentially have important implications also for the evolution of planets by inhibiting efficient, large-scale convection (Stevenson 1985; Leconte & Chabrier 2012).”
• THE IMPRINT OF EXOPLANET FORMATION HISTORY ON OBSERVABLE PRESENT-DAY SPECTRA OF HOT JUPITERS (2016, background): “Following the usual paradigm of fully convective interiors in giant planets, semi-convection that could occur due to compositional gradients is neglected (Stevenson 1985; Leconte & Chabrier 2012).”
• MAKE SUPER-EARTHS, NOT JUPITERS: ACCRETING NEBULAR GAS ONTO SOLID CORES AT 0.1 AU AND BEYOND (2014, background): “(In models of Saturn and Jupiter, ∇µ can be positive because of imperfect mixing of solids, immiscibility of helium, and core erosion; see Leconte & Chabrier 2012, 2013.”
• JUPITER MODELS WITH IMPROVED AB INITIO HYDROGEN EQUATION OF STATE (H-REOS.2) (2011, background): “Therefore, Leconte & Chabrier (2012) investigated the possibility of layered convection in Jupiter, where heat is transported inefficiently by diffusion across thin stable layers, separated vertically by convective cells.”
• On the Cool Side: Modeling the Atmospheres of Brown Dwarfs and Giant Planets (2014, background): “These 4 Marley & Robinson assumptions can break down if there are composition gradients that impede convection or deep windows in molecular opacity (e.g., Guillot et al. 1994; Leconte & Chabrier 2012), which are eventualities that we ignore here.”
• Comparing Jupiter interior structure models to Juno gravity measurements and the role of a dilute core (2017, methodology): “Constraining this requires an evolutionary model to constrain the density and temperature gradients through the dilute core [Leconte and Chabrier, 2012, 2013] and has not WAHL ET AL.”
• New Models of Jupiter in the Context of Juno and Galileo (2019, methodology): “Although, as examined in §6.2, the present models fulfill the constraints required for the onset and persistence of layered convection (Leconte and Chabrier (2012), Leconte and Chabrier (2013)), whether such structures can persist during Jupiter’s, or in fact any gaseous planet cooling history…”
• THE MASS–METALLICITY RELATION FOR GIANT PLANETS (2015, unknown): “Layered semi-convective models are also consistent with structure models (e.g., Leconte & Chabrier 2012), though more work is needed to understand the origin and maintenance of such layers.”
• New indication for a dichotomy in the interior structure of Uranus and Neptune from the application of modified shape and rotation data (2012, background): “If some part of the interior, for Uranus possibly 0.45– 0.5MU (§ 3.3), is stable to convection so that heat cannot escape efficiently from the region below, then the superadiabaticity of the temperature gradient there can be nonnegligible (Leconte and Chabrier, 2012).”
• AB INITIO SIMULATIONS FOR MATERIAL PROPERTIES ALONG THE JUPITER ADIABAT (2012, background): “Lastly, while standard giant planet models assume an adiabatic, convective interior, the high thermal diffusivity together with a possible presence of a compositional gradient might suppress large-scale convection (Chabrier & Baraffe 2007; Leconte & Chabrier 2012).”
• Characterization of exoplanets from their formation - II. The planetary mass-radius relationship (2012, background): “2.2.2, and the assumption of an effective convective energy transport may break down due to composition gradients (e.g. Stevenson 1985; Leconte & Chabrier 2012).”
• Resonance locking as the source of rapid tidal migration in the Jupiter and Saturn moon systems (2016, background): “Stable stratification (or semiconvective layers) has also been advocated to exist based c© 0000 RAS, MNRAS 000, 000–000 on Saturn’s thermal evolution (Leconte & Chabrier 2012, 2013).”
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e (2020, background): “We neglect the, potentially very important, effect of compositional gradients in the planet, that may lead to atmospheric abundances being different from the bulk of the planet (e.g., Leconte & Chabrier 2012; Vazan et al. 2018).”
• Characterization of exoplanets from their formation - I. Models of combined planet formation and evolution (2012, background): “While these assumptions are mainly made for simplicity of the models, they are not necessarily correct (Stevenson 1985; Leconte & Chabrier 2012).”