Related papers: Chemical variation with altitude and longitude on …
Planets with non-zero obliquity and/or orbital eccentricity experience seasonal variations of stellar irradiation at local latitudes. The extent of the atmospheric response can be crudely estimated by the ratio between the orbital timescale…
We present a parameterization for the eddy diffusion profile of gas giant exoplanets based on physical phenomena and we explore how the parameterized eddy profile impacts the chemical composition, the thermal structure, the haze…
To date, the ability for observers to reveal the composition or thermal structure of an exoplanet's atmosphere has rested on two techniques: high-contrast direct imaging and time-series observations of transiting exoplanets. The former is…
Ultraviolet (UV) absorption cross sections are an essential ingredient of photochemical atmosphere models. Exoplanet searches have unveiled a large population of short-period objects with hot atmospheres, very different from what we find in…
Context: Low-mass stars and extrasolar planets have ultra-cool atmospheres where a rich chemistry occurs and clouds form. The increasing amount of spectroscopic observations for extrasolar planets requires self-consistent model atmosphere…
Relatively long-period nonsynchronized planets---such as warm Jupiters---potentially retain the primordial rotation, eccentricity, and obliquity that might encapsulate information on planetary climate and formation processes. To date, there…
The characterization of exoplanetary atmospheres has come of age in the last decade, as astronomical techniques now allow for albedos, chemical abundances, temperature profiles and maps, rotation periods and even wind speeds to be measured.…
We have developed a 1D planetary atmosphere model that solves in a self-consistent manner the evolution of temperature and disequilibrium chemistry in the vertical direction. Thermochemical kinetics is based on a reaction network built from…
Inferring the properties of exoplanets from their atmospheres, while confronting low resolution and low signal-to-noise in the context of the quantities we want to derive, poses rigorous demands upon the data collected from observation.…
Atmospheric escape is an important process that controls the long-term evolution of close-in planets. We perform radiation hydrodynamics simulations of photo-evaporation of exoplanets' atmospheres to study the effect of photoelectric…
Neptune remains a mysterious world that deserves further exploration and is a high-priority objective for a future planetary mission in order to better understand the formation and evolution of ice giant planets. We have developed a coupled…
The transmission spectra of exoplanet atmospheres observed with the Hubble Space Telescope (HST) in the near-infrared range (1.1-1.65$\mu$m) frequently show evidence for some combination of clouds and hazes. Identification of systematic…
We have developed 1-D photochemical and thermochemical kinetics and diffusion models for the transiting exoplanets HD 189733b and HD 209458b to study the effects of disequilibrium chemistry on the atmospheric composition of "hot Jupiters."…
We present model atmospheres for an Earth-like planet orbiting the entire grid of main sequence FGK stars with effective temperatures ranging from Teff = 4250K to Teff = 7000K in 250K intervals. We model the remotely detectable spectra of…
Comparatively little is known about atmospheric chemistry on Uranus and Neptune, because remote spectral observations of these cold, distant ``Ice Giants'' are challenging, and each planet has only been visited by a single spacecraft during…
The composition of the outer 100 m of a neutron star sets the heat flux that flows outwards from the core. For an accreting neutron star in an X-ray transient, the thermal quiescent flux depends sensitively on the amount of hydrogen and…
Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of…
Sub-Neptunes and Neptunes are often modeled with distinct, fully convective layers. Yet, there are several arguments for compositions gradients that can inhibit convection. In these regions, energy transport depends on the thermal…
Neptunes and sub-Neptunes are typically modeled under the assumption that the interior is adiabatic and consists of distinct layers. However, formation models indicate that composition gradients can exist. Such composition gradients can…
We investigate the impact of photochemical hazes and disequilibrium gases on the thermal structure of hot-Jupiters, using a detailed 1-D radiative-convective model. We find that the inclusion of photochemical hazes results in major heating…