The atmospheric circulation of the super Earth GJ 1214b: Dependence on composition and metallicity

Abstract

We present three-dimensional atmospheric circulation models of GJ 1214b, a 2.7 Earth-radius, 6.5 Earth-mass super Earth detected by the MEarth survey. Here we explore the planet's circulation as a function of atmospheric metallicity and atmospheric composition, modeling atmospheres with a low mean-molecular weight (i.e., H2-dominated) and a high mean-molecular weight (i.e. water- and CO2-dominated). We find that atmospheres with a low mean-molecular weight have strong day-night temperature variations at pressures above the infrared photosphere that lead to equatorial superrotation. For these atmospheres, the enhancement of atmospheric opacities with increasing metallicity lead to shallower atmospheric heating, larger day-night temperature variations and hence stronger superrotation. In comparison, atmospheres with a high mean-molecular weight have larger day-night and equator-to-pole temperature variations than low mean-molecular weight atmospheres, but differences in opacity structure and energy budget lead to differences in jet structure. The circulation of a water-dominated atmosphere is dominated by equatorial superrotation, while the circulation of a CO2-dominated atmosphere is instead dominated by high-latitude jets. By comparing emergent flux spectra and lightcurves for 50x solar and water-dominated compositions, we show that observations in emission can break the degeneracy in determining the atmospheric composition of GJ 1214b. The variation in opacity with wavelength for the water-dominated atmosphere leads to large phase variations within water bands and small phase variations outside of water bands. The 50x solar atmosphere, however, yields small variations within water bands and large phase variations at other characteristic wavelengths. These observations would be much less sensitive to clouds, condensates, and hazes than transit observations.

12 pages, 11 figures, 2 tables, accepted to ApJ

References in corpus (6)

• Sodium Absorption From the Exoplanetary Atmosphere of HD189733b Detected in the Optical Transmission Spectrum
• The Atmospheric Signatures of Super-Earths: How to Distinguish Between Hydrogen-Rich and Hydrogen-Poor Atmospheres
• Dynamics and Disequilibrium Carbon Chemistry in Hot Jupiter Atmospheres, With Application to HD 209458b
• Atmospheric Dynamics of Short-period Extra Solar Gas Giant Planets I: Dependence of Night-Side Temperature on Opacity
• Atmospheric Circulation of Eccentric Hot Neptune GJ436b
• Spitzer Transits of the Super-Earth GJ1214b and Implications for Its Atmosphere

Cited by in corpus (39)

• HAT-P-26b: A Neptune-Mass Exoplanet with a Well Constrained Heavy Element Abundance
• The Complete transmission spectrum of WASP-39b with a precise water constraint
• The Atmospheric Circulation of the Hot Jupiter WASP-43b: Comparing Three-Dimensional Models to Spectrophotometric Data
• A reflective, metal-rich atmosphere for GJ 1214b from its JWST phase curve
• High temperature condensate clouds in super-hot Jupiter atmospheres
• FastChem 2: An improved computer program to determine the gas-phase chemical equilibrium composition for arbitrary element distributions
• The UK Met Office GCM with a sophisticated radiation scheme applied to the hot Jupiter HD 209458b
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• Effects of Bulk Composition on The Atmospheric Dynamics on Close-in Exoplanets
• A Semi-Analytical Model of Visible-Wavelength Phase Curves of Exoplanets and Applications to Kepler-7 b and Kepler-10 b
• Deciphering thermal phase curves of dry, tidally locked terrestrial planets
• Linking the Climate and Thermal Phase Curve of 55 Cancri e
• The Hazy and Metal-Rich Atmosphere of GJ 1214 b Constrained by Near and Mid-Infrared Transmission Spectroscopy
• 3D simulations of photochemical hazes in the atmosphere of hot Jupiter HD 189733b
• Signatures of Strong Magnetization and Metal-Poor Atmosphere for a Neptune-Size Exoplanet
• Diurnal variations in the stratosphere of the ultrahot giant exoplanet WASP-121b
• Connecting the dots: A versatile model for the atmospheres of tidally locked Super-Earths
• Simulating gas giant exoplanet atmospheres with Exo-FMS: Comparing semi-grey, picket fence and correlated-k radiative-transfer schemes
• Photochemical hazes in sub-Neptunian atmospheres with focus on GJ 1214 b
• A Hubble PanCET Study of HAT-P-11b: A Cloudy Neptune with a Low Atmospheric Metallicity
• Extremely long convergence times in a 3D GCM simulation of the sub-Neptune Gliese 1214b
• The carbon-to-oxygen ratio: implications for the spectra of hydrogen-dominated exoplanet atmospheres
• Atmospheres on Nonsynchronized Eccentric-tilted Exoplanets I: Dynamical Regimes
• The Impact of Phase Equilibrium Cloud Models on GCM Simulations of GJ~1214b
• Ohmic Dissipation in Mini-Neptunes
• The Equatorial Jet Speed on Tidally Locked Planets: I -- Terrestrial Planets
• Towards a comprehensive model of Earth's disk-integrated Stokes vector
• Atmospheres on Nonsynchronized Eccentric-tilted Exoplanets II: Thermal Light Curves
• The Dark World: A Tale of WASP-43b in Reflected Light with HST WFC3/UVIS
• Atmospheric dynamics of temperate sub-Neptunes. Part I: dry dynamics
• Thermal Phase Curves of XO-3b: an Eccentric Hot Jupiter at the Deuterium Burning Limit
• Clouds and Hazes in GJ 1214b's Metal-Rich Atmosphere
• Atmospheric Characterization via Broadband Color Filters on the PLAnetary Transits and Oscillations of stars (PLATO) Mission
• Is the hot, dense sub-Neptune TOI-824b an exposed Neptune mantle? Spitzer detection of the hot day side and reanalysis of the interior composition
• ARES VI: Viability of one-dimensional retrieval models for transmission spectroscopy characterization of exo-atmospheres in the era of JWST and Ariel
• Examining NHD vs QHD in the GCM THOR with non-grey radiative transfer for the hot Jupiter regime
• Reflected-light Phase Curves with PICASO: A Kepler-7b Case Study
• Cloudy solutions for the clear skies of WASP-80b: 3D cloud feedback on the atmosphere and spectra of a warm Jupiter
• Cloudy and Cloud-free Thermal Phase Curves with PICASO: Applications to WASP-43b