Increased Heat Transport in Ultra-hot Jupiter Atmospheres through H 2 Dissociation and Recombination

@article{Bell2018IncreasedHT,
  title={Increased Heat Transport in Ultra-hot Jupiter Atmospheres through H 2 Dissociation and Recombination},
  author={Taylor J. Bell and Nicolas B. Cowan},
  journal={The Astrophysical Journal},
  year={2018},
  volume={857}
}
A new class of exoplanets is beginning to emerge: planets with dayside atmospheres that resemble stellar atmospheres as most of their molecular constituents dissociate. The effects of the dissociation of these species will be varied and must be carefully accounted for. Here we take the first steps toward understanding the consequences of dissociation and recombination of molecular hydrogen (H2) on atmospheric heat recirculation. Using a simple energy balance model with eastward winds, we… Expand

Figures from this paper

Evidence for H2 Dissociation and Recombination Heat Transport in the Atmosphere of KELT-9b
Phase curve observations provide an opportunity to study the full energy budgets of exoplanets by quantifying the amount of heat redistributed from their daysides to their nightsides. TheoriesExpand
Pseudo-2D modelling of heat redistribution through H2 thermal dissociation/recombination: consequences for ultra-hot Jupiters
Thermal dissociation and recombination of molecular hydrogen, H2, in the atmospheres of ultra-hot Jupiters (UHJs) has been shown to play an important role in global heat redistribution. This, inExpand
The Atmospheric Circulation of Ultra-hot Jupiters
Recent observations of ultra-hot Jupiters with dayside temperatures in excess of $2500~\mathrm{K}$ have found evidence for new physical processes at play in their atmospheres. In this work, weExpand
From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context
A new class of exoplanets has emerged: the ultra hot Jupiters, the hottest close-in gas giants. Most of them have weaker than expected spectral features in the $1.1-1.7\mu m$ bandpass probed byExpand
Effects of dissociation/recombination on the day-night temperature contrasts of ultra-hot Jupiters
Secondary eclipse observations of ultra-hot Jupiters have found evidence that hydrogen is dissociated on their daysides. Additionally, full-phase light curve observations of ultra-hot Jupiters show aExpand
Extremely Irradiated Hot Jupiters: Non-Oxide Inversions, H- Opacity, and Thermal Dissociation of Molecules
Extremely irradiated hot Jupiters, exoplanets reaching dayside temperatures ${>}$2000 K, stretch our understanding of planetary atmospheres and the models we use to interpret observations. WhileExpand
Atmospheric characterization of the ultra-hot Jupiter MASCARA-2b/KELT-20b.
Ultra hot Jupiters orbit very close to their host star and consequently receive strong irradiation that makes their atmospheric chemistry different from the common gas giants. Here, we study theExpand
Sparkling nights and very hot days on WASP-18b: the formation of clouds and the emergence of an ionosphere
WASP-18b is an utra-hot Jupiter with a temperature difference of upto 2500K between day and night. Such giant planets begin to emerge as planetary laboratory for understanding cloud formation and gasExpand
Uniformly hot nightside temperatures on short-period gas giants.
Short-period gas giants (hot Jupiters) on circular orbits are expected to be tidally locked into synchronous rotation, with permanent daysides that face their host stars, and permanent nightsidesExpand
Coupled day–night models of exoplanetary atmospheres
We provide a new framework to model the day side and night side atmospheres of irradiated exoplanets using 1-D radiative transfer by incorporating a self-consistent heat flux carried by circulationExpand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 39 REFERENCES
Atmospheric heat redistribution on hot jupiters
Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy absorbed on their daysides—andExpand
Atmospheric Circulation of Hot Jupiters: Dayside-Nightside Temperature Differences
The full-phase infrared light curves of low-eccentricity hot Jupiters show a trend of increasing dayside-to-nightside brightness temperature difference with increasing equilibrium temperature. HereExpand
Magnetic Scaling Laws for the Atmospheres of Hot Giant Exoplanets
We present scaling laws for advection, radiation, magnetic drag, and ohmic dissipation in the atmospheres of hot giant exoplanets. In the limit of weak thermal ionization, ohmic dissipation increasesExpand
H- Opacity and Water Dissociation in the Dayside Atmosphere of the Very Hot Gas Giant WASP-18b
We present one of the most precise emission spectra of an exoplanet observed so far. We combine five secondary eclipses of the hot Jupiter WASP-18b (T day ~ 2900 K) that we secured between 1.1 andExpand
The Statistics of Albedo and Heat Recirculation on Hot Exoplanets
If both the day-side and night-side effective temperatures of a planet can be measured, it is possible to estimate its Bond albedo, 0 0.8 ?m?to estimate day-side effective temperatures, T d, andExpand
Effects of Bulk Composition on the Atmospheric Dynamics on Close-in Exoplanets
Super Earths and mini Neptunes likely have a wide range of atmospheric compositions, ranging from low-molecular mass atmospheres of H2 to higher molecular atmospheres of water, CO2, N2, or otherExpand
Direct Measure of Radiative and Dynamical Properties of an Exoplanet Atmosphere
Two decades after the discovery of 51 Peg b, the formation processes and atmospheres of short-period gas giants remain poorly understood. Observations of eccentric systems provide key insights onExpand
An ultrahot gas-giant exoplanet with a stratosphere
TLDR
A near-infrared thermal spectrum for the ultrahot gas giant WASP-121b, which has an equilibrium temperature of approximately 2,500 kelvin, is reported, implying that a substantial fraction of incident stellar radiation is retained at high altitudes in the atmosphere, possibly by absorbing chemical species such as gaseous vanadium oxide and titanium oxide. Expand
Three-dimensional Modeling of Hot Jupiter Atmospheric Flows
We present a three-dimensional hot Jupiter model, extending from 200 bar to 1 mbar, using the Intermediate General Circulation Model from the University of Reading. Our horizontal spectral resolutionExpand
Transitions in the cloud composition of hot Jupiters
Over a large range of equilibrium temperatures, clouds shape the transmission spectrum of hot Jupiter atmospheres, yet their composition remains unknown. Recent observations show that the KeplerExpand
...
1
2
3
4
...