The ARCiS framework for Exoplanet Atmospheres: The Cloud Transport Model

Abstract

Understanding of clouds is instrumental in interpreting current and future spectroscopic observations of exoplanets. Modelling clouds consistently is complex, since it involves many facets of chemistry, nucleation theory, condensation physics, coagulation, and particle transport. We develop a simple physical model for cloud formation and transport, efficient and versatile enough that it can be used in modular fashion for parameter optimization searches of exoplanet atmosphere spectra. The transport equations are formulated in 1D, accounting for sedimentation and diffusion. The grain size is obtained through a moment method. For simplicity, only one cloud species is considered and the nucleation rate is parametrized. From the resulting physical profiles we simulate transmission spectra covering the visual to mid-IR wavelength range. We apply our models towards KCl clouds in the atmosphere of GJ1214 b and towards MgSiO3 clouds of a canonical hot-Jupiter. We find that larger cloud diffusivity $K_{zz}$ increases the thickness of the cloud, pushing the $\tau =1$ surface to a lower pressure layer higher in the atmosphere. A larger nucleation rate also increases the cloud thickness while it suppresses the grain size. Coagulation is most important at high nuclei injection rates (${\dot{\Sigma }}_n$) and low $K_{zz}$. We find that the investigated combinations of $K_{zz}$ and ${\dot{\Sigma }}_n$ greatly affect the transmission spectra in terms of the slope at near-IR wavelength (a proxy for grain size), the molecular features seen at ~1\micr (which disappear for thick clouds, high in the atmosphere), and the 10\micr silicate feature, which becomes prominent for small grains high in the atmosphere. The result of our hybrid approach -- aimed to provide a good balance between physical consistency and computational efficiency -- is ideal towards interpreting (future) spectroscopic observations of exoplanets.

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References in corpus (36)

• The effects of snowlines on C/O in planetary atmospheres
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• Precipitating Condensation Clouds in Substellar Atmospheres
• A super-Earth transiting a nearby low-mass star
• On the radiative equilibrium of irradiated planetary atmospheres
• Neglected Clouds in T and Y Dwarf Atmospheres
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• A Systematic Retrieval Analysis of Secondary Eclipse Spectra I: A Comparison of Atmospheric Retrieval Techniques
• A population study of gaseous exoplanets
• Modeling optical properties of cosmic dust grains using a distribution of hollow spheres
• Model atmospheres of irradiated exoplanets: The influence of stellar parameters, metallicity, and the C/O ratio
• Formation of Jupiter using opacities based on detailed grain physics
• Observing transiting planets with JWST -- Prime targets and their synthetic spectral observations
• A consistent retrieval analysis of 10 Hot Jupiters observed in transmission
• On the water delivery to terrestrial embryos by ice pebble accretion
• Atmospheric Signatures of Giant Exoplanet Formation by Pebble Accretion
• Dust in Brown Dwarfs and Extra-solar Planets I. Chemical composition and spectral appearance of quasi-static cloud layers
• A self-consistent cloud model for brown dwarfs and young giant exoplanets: comparison with photometric and spectroscopic observations
• Large Scale Molecular Dynamics Simulations of Homogeneous Nucleation
• An Atmospheric Structure Equation for Grain Growth
• Can grain growth explain transition disks?
• Formation of Silicate and Titanium Clouds on Hot Jupiters
• Theoretical transmission spectra of exoplanet atmospheres with hydrocarbon haze: Effect of creation, growth, and settling of haze particles. I. Model description and first results
• Disk evolution, element abundances and cloud properties of young gas giant planets
• Grain opacity and the bulk composition of extrasolar planets. II. An analytical model for the grain opacity in protoplanetary atmospheres
• Sedimentation Efficiency of Condensation Clouds in Substellar Atmospheres
• Microphysics of KCl and ZnS Clouds on GJ 1214b
• Electrostatic Barrier against Dust Growth in Protoplanetary Disks. I. Classifying the Evolution of Size Distribution
• A panoptic model for planetesimal formation and pebble delivery
• Modification of the classical nucleation theory based on molecular simulation data for surface tension, critical nucleus size, and nucleation rate
• Toward the analysis of JWST exoplanet spectra: Identifying troublesome model parameters
• C/O and O/H Ratios Suggest Some Hot Jupiters Originate Beyond the Snow Line
• Microphysical Modeling of Mineral Clouds in GJ1214 b and GJ436 b: Predicting Upper Limits on the Cloud-Top Height
• The contribution of the ARIEL space mission to the study of planetary formation
• A Condensation-Coalescence Cloud Model for Exoplanetary Atmospheres: Formulation and Test Applications to Terrestrial and Jovian Clouds
• Random sampling technique for ultra-fast computations of molecular opacities for exoplanet atmospheres

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