The Effect of Clouds as an Additional Opacity Source on the Inferred Metallicity of Giant Exoplanets

Anna Julia Poser; Nadine Nettelmann; Ronald Redmer

doi:10.3390/atmos10110664

journal article Open Access Oct 30, 2019

The Effect of Clouds as an Additional Opacity Source on the Inferred Metallicity of Giant Exoplanets

Anna Julia Poser Nadine Nettelmann Ronald Redmer

Atmosphere Vol. 10 No. 11 pp. 664 · MDPI AG

View at Publisher Save 10.3390/atmos10110664

Abstract

Atmospheres regulate the planetary heat loss and therefore influence planetary thermal evolution. Uncertainty in a giant planet’s thermal state contributes to the uncertainty in the inferred abundance of heavy elements it contains. Within an analytic atmosphere model, we here investigate the influence that different cloud opacities and cloud depths can have on the metallicity of irradiated extrasolar gas giants, which is inferred from interior models. In this work, the link between inferred metallicity and assumed cloud properties is the thermal profile of atmosphere and interior. Therefore, we perform coupled atmosphere, interior, and evolution calculations. The atmosphere model includes clouds in a much simplified manner; it includes long-wave absorption but neglects shortwave scattering. Within that model, we show that optically thick, high clouds have negligible influence, whereas deep-seated, optically very thick clouds can lead to warmer deep tropospheres and therefore higher bulk heavy element mass estimates. For the young hot Jupiter WASP-10b, we find a possible enhancement in inferred metallicity of up to 10% due to possible silicate clouds at ∼0.3 bar. For WASP-39b, whose observationally derived metallicity is higher than predicted by cloudless models, we find an enhancement by at most 50%. However, further work on cloud properties and their self-consistent coupling to the atmospheric structure is needed in order to reduce uncertainties in the choice of model parameter values, in particular of cloud opacities.

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References

55

[1]

Venturini "Planet formation with envelope enrichment: New insights on planetary diversity" A&A (2016) 10.1051/0004-6361/201628828

[2]

Wakeford "The complete transmission spectrum of WASP-39b with a precise water constraint" Astron. J. (2018) 10.3847/1538-3881/aa9e4e

[3]

Thorngren "Connecting giant planet atmosphere and interior modeling: constraints on atmospheric metal enrichment" Astrophys. J. Lett. (2019) 10.3847/2041-8213/ab43d0

[4]

Maciejewski "Analysis of new high-precision transit light curves of WASP-10 b: starspot occultations, small planetary radius, and high metallicity" A&A (2011) 10.1051/0004-6361/201117127

[5]

Thorngren "The mass-metallicity relation for giant planets" Astrophys. J. (2016) 10.3847/0004-637x/831/1/64

[6]

Morley "Quantitatively assessing the role of clouds in the transmission spectrum of GJ 1214b" Astrophys. J. (2013) 10.1088/0004-637x/775/1/33

[7]

Lines "Simulating the cloudy atmospheres of HD 209458 b and HD 189733 b with the 3D Met Office Unified Model" A&A (2018) 10.1051/0004-6361/201732278

[8]

Seager "The Atmospheric Signatures of Super-Earths: How to Distinguish Between Hydrogen-Rich and Hydrogen-Poor Atmospheres" Astrophys. J. (2009) 10.1088/0004-637x/690/2/1056

[9]

Thorngren "The intrinsic temperature and radiative-convective boundary depth in the atmospheres of hot Jupiters" Astrophys. J. Lett. (2019) 10.3847/2041-8213/ab43d0

[10]

Podolak "Effect of non-adiabatic thermal profiles on the inferred composition of Uranus and Neptune" Mon. Not. R. Astron. Soc. (2019) 10.1093/mnras/stz1467

[11]

Heng "On the effects of clouds and hazes in the atmospheres of hot Jupiters: Semi-analytical temperature-pressure profiles" Mon. Not. R. Astron. Soc. (2012) 10.1111/j.1365-2966.2011.19943.x

[12]

Linder "Evolutionary models of cold and low-mass planets: Cooling curves, magnitudes, and detectability" A&A (2019) 10.1051/0004-6361/201833873

[13]

Kurosaki "Acceleration of Cooling of Ice Giants by Condensation in Early Atmospheres" Astron. J. (2017) 10.3847/1538-3881/aa6faf

[14]

Barman "Irradiated Planets" Astrophys. J. (2001) 10.1086/321610

[15]

Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458

I. Baraffe, G. Chabrier, T. S. Barman et al.

Astronomy & Astrophysics 2003 10.1051/0004-6361:20030252

[16]

Kataria "The atmospheric circulation of a nine-hot-Jupiter sample: Probing circulation and chemistry over a wide phase space" Astrophys. J. (2016) 10.3847/0004-637x/821/1/9

[17]

Bouwman "Observing transiting planets with JWST. Prime targets and their synthetic spectral observations" A&A (2017) 10.1051/0004-6361/201629800

[18]

Johnson "A smaller radius for the transiting exoplanet WASP-10b" Astrophys. J. Lett. (2009) 10.1088/0004-637x/692/2/l100

[19]

Christian "WASP-10b: A 3MJ, gas-giant planet transiting a late-type K star" Mon. Not. R. Astron. Soc. (2009) 10.1111/j.1365-2966.2008.14164.x

[20]

Maciejewski "Transit timing variation and activity in the WASP-10 planetary system" Mon. Not. R. Astron. Soc. (2010) 10.1111/j.1365-2966.2010.17753.x

[21]

Faedi "WASP-39b: A highly inflated Saturn-mass planet orbiting a late G-type star" A&A (2011) 10.1051/0004-6361/201116671

[22]

Mordasini "The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters" Astrophys. J. (2016) 10.3847/0004-637x/832/1/41

[23]

Lodders "Solar system abundances and condensation temperatures of the elements" Astrophys. J. (2003) 10.1086/375492

[24]

Saumon "An equation of state for low-mass stars and giant planets" Astrophys. J. Suppl. (1995) 10.1086/192204

[25]

Hubbard "Optimized Jupiter, Saturn, and Uranus interior models" Icarus (1989) 10.1016/0019-1035(89)90072-9

[26]

Nettelmann "Thermal evolution and structure models of the transiting super-Earth GJ 1214b" Astrophys. J. (2011) 10.1088/0004-637x/733/1/2

[27]

The Interior Structure, Composition, and Evolution of Giant Planets

Jonathan J. Fortney, Nadine Nettelmann

Space Science Reviews 2010 10.1007/s11214-009-9582-x

[28]

Guillot "On the radiative equilibrium of irradiated planetary atmospheres" A&A (2010) 10.1051/0004-6361/200913396

[29]

Marley "Reflected spectra and albedos of extrasolar giant planets. I. Clear and cloudy atmospheres" Astrophys. J. (1999) 10.1086/306881

[30]

Gelino "Model Bond Albedos of Extrasolar Giant Planets" Phys. Chem. Earth (1999)

[31]

Sudarsky "Albedo and reflection spectra of extrasolar giant planets" Am. Astron. Soc. (2000)

[32]

Madhusudhan, N., Knutson, H., Fortney, J.J., and Barman, T. (2014). Exoplanetary atmospheres. Protostars and Planets VI, University of Arizona Press. 10.2458/azu_uapress_9780816531240-ch032

[33]

Li "Less absorbed solar energy and more internal heat for Jupiter" Nat. Commun. (2018) 10.1038/s41467-018-06107-2

[34]

Heng "Analytical models of exoplanetary atmospheres. II. Radiative transfer via the two-stream approximation" Astrophys. J. Suppl. (2014) 10.1088/0067-0049/215/1/4

[35]

Fortney "Planetary radii across five orders of magnitude in mass and stellar insolation: Application to transits" Astrophys. J. (2007) 10.1086/512120

[36]

Fortney "Atmosphere, Interior, and Evolution of the Metal-rich Transiting Planet HD 149036b" Astrophys. J. (2006) 10.1086/500920

[37]

Dullemond "Model atmospheres of irradiated exoplanets: The influence of stellar parameters, metallicity, and the C/O ratio" Astrophys. J. (2015) 10.1088/0004-637x/813/1/47

[38]

Wakeford "High-temperature condensate clouds in super-hot Jupiter atmospheres" Mon. Not. R. Astron. Soc. (2017) 10.1093/mnras/stw2639

[39]

Valencia "Bulk composition of GJ 1214b and other sub-neptune exoplanets" Astrophys. J. (2013) 10.1088/0004-637x/775/1/10

[40]

Freedman "Line and mean opacities for ultracool dwarfs and extrasolar planets" Astrophys. J. Suppl. (2008) 10.1086/521793

[41]

Marley, M.S. (2000). The Role of Condensates in L- and T-dwarf Atmospheres. From Giant Planets to Cool Stars, ASP.

[42]

Lodders, K., and Fegley, B. (2006). Chemistry of low mass substellar objects. Astrophysics Update 2, Springer. 10.1007/3-540-30313-8_1

[43]

Morley "Thermal emission and reflected light spectra of super earths with flat transmission spectra" Astrophys. J. (2015) 10.1088/0004-637x/815/2/110

[44]

Alexander "Giant planet migration, disk evolution, and the origin of transitional disks" Astrophys. J. (2009) 10.1088/0004-637x/704/2/989

[45]

Bayesian Analysis of Hot-Jupiter Radius Anomalies: Evidence for Ohmic Dissipation?

Daniel P. Thorngren, Jonathan J. Fortney

The Astronomical Journal 2018 10.3847/1538-3881/aaba13

[46]

Leconte "Condensation-inhibited convection in hydrogen-rich atmospheres" A&A (2017) 10.1051/0004-6361/201629140

[47]

A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion

David K. Sing, Jonathan J. Fortney, Nikolay Nikolov et al.

Nature 2016 10.1038/nature16068

[48]

Nikolov "VLT FORS2 comparative transmission spectroscopy: Detection of Na in the atmosphere of WASP-39b from the ground" Astrophys. J. (2016) 10.3847/0004-637x/832/2/191

[49]

Becker "Ab initio equation of state for hydrogen (H-REOS.3) and helium (He-REOS.3) and their implications for the interior of brown dwarfs" Astrophys. J. Suppl. (2014) 10.1088/0067-0049/215/2/21

[50]

Chabrier "Heat transport in giant (exo)planets: A new perspective" Astrophys. J. Lett. (2007) 10.1086/518473

Showing 50 of 55 references

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References

Details

Published: Oct 30, 2019
Vol/Issue: 10(11)
Pages: 664
License: View

Authors

A

Anna Julia Poser

Institut für Physik, Universität Rostock, D-18051 Rostock, Germany

N

Nadine Nettelmann

Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt (DLR) Berlin, D-12489 Berlin, Germany

R

Ronald Redmer

Institut für Physik, Universität Rostock, D-18051 Rostock, Germany

Funding

Deutsche Forschungsgemeinschaft Award: Priority Programme “Exploring the Diversity of Extrasolar Planets” (SPP 1992)

Cite This Article

Anna Julia Poser, Nadine Nettelmann, Ronald Redmer (2019). The Effect of Clouds as an Additional Opacity Source on the Inferred Metallicity of Giant Exoplanets. Atmosphere, 10(11), 664. https://doi.org/10.3390/atmos10110664

The Effect of Clouds as an Additional Opacity Source on the Inferred Metallicity of Giant Exoplanets

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