Convective shutdown in the atmospheres of lava worlds

2024/12/16 by Harrison Nicholls, Raymond T. Pierrehumbert, Tim Lichtenberg +2 · 3 voices · 4 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astro and Planetary Science #High-pressure geophysics and materials #Stellar, planetary, and galactic studies #astro-ph.EP

paper · pdf · doi:10.1093/mnras/stae2772

openalex publication_date 2024/12/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

ABSTRACT Atmospheric energy transport is central to the cooling of primordial magma oceans. Theoretical studies of atmospheres on lava planets have assumed that convection is the only process involved in setting the atmospheric temperature structure. This significantly influences the ability for a magma ocean to cool. It has been suggested that convective stability in these atmospheres could preclude permanent magma oceans. We develop a new 1D radiative-convective model in order to investigate when the atmospheres overlying magma oceans are convectively stable. Using a coupled interior-atmosphere framework, we simulate the early evolution of two terrestrial-mass exoplanets: TRAPPIST-1 c and HD 63433 d. Our simulations suggest that the atmosphere of HD 63433 d exhibits deep isothermal layers which are convectively stable. However, it is able to maintain a permanent magma ocean and an atmosphere depleted in \mathrmH₂O. It is possible to maintain permanent magma oceans underneath atmospheres without convection. Absorption features of \mathrmCO₂ and \mathrmSO₂ within synthetic emission spectra are associated with mantle redox state, meaning that future observations of HD 63433 d may provide constraints on the geochemical properties of a magma ocean analogous with the early Earth. Simulations of TRAPPIST-1 c indicate that it is expected to have solidified within 100 M\rm yr, outgassing a thick atmosphere in the process. Cool isothermal stratospheres generated by low-molecular-weight atmospheres can mimic the emission of an atmosphere-less body. Future work should consider how atmospheric escape and chemistry modulates the lifetime of magma oceans, and the role of tidal heating in sustaining atmospheric convection.

Citations

• The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use
• Julia: A Fresh Approach to Numerical Computing
• The HITRAN2020 molecular spectroscopic database
• Atmospheric Retrievals Suggest the Presence of a Secondary Atmosphere and Possible Sulfur Species on L98-59 d from JWST Nirspec G395H Transmission Spectroscopy
• Magma Ocean Evolution at Arbitrary Redox State

Cited by

• Coupled atmospHere Interior modeL Intercomparison (CHILI) Protocol Version 1.0: A CUISINES Intercomparison Project of Magma Ocean Models
• Onset of habitable conditions on the Hadean Earth set by feedback between tides and greenhouse forcing
• Magma ocean interactions can explain JWST observations of the sub-Neptune TOI-270 d
• Mantle convection and nightside volcanism on lava world K2-141 b

Discussions

• Super interesting new study on convection in lava world atmospheres by @nichollsh.bsky.social today on arxiv.org/abs/2412.11987! Two main findings: [bsky, 10 points, 1 comments]
• Our new paper on atmospheric convection on lava worlds is now on arXiv (accepted in MNRAS). We model the early time-evolution of two terrestrial-mass planets, and find that their atmospheres are not [bsky, 8 points, 1 comments]
• Our new paper on evolution of a primordial magma ocean coupled to a radiative-convective atmosphere including atmospheric chemistry, this time allowing for convective shutdown,. Led by Harrison Nichol [bsky, 4 points, 1 comments]

Related

• Absence of a Runaway Greenhouse Limit on Lava Planets
• Magma Ocean Evolution at Arbitrary Redox State
• Atmospheric evolution through outgassing and escape on young molten rocky exoplanets
• Mantle convection and nightside volcanism on lava world K2-141 b
• Rock vapour is opaque: implications for dynamics and observations of lava planets