Skip to Main content Skip to Navigation
Journal articles

Formation of Silicate and Titanium Clouds on Hot Jupiters

Abstract : We present the first application of a bin-scheme microphysical and vertical transport model to determine the size distribution of titanium and silicate cloud particles in the atmospheres of hot Jupiters. We predict particle size distributions from first principles for a grid of planets at four representative equatorial longitudes, and investigate how observed cloud properties depend on the atmospheric thermal structure and vertical mixing. The predicted size distributions are frequently bimodal and irregular in shape. There is a negative correlation between the total cloud mass and equilibrium temperature as well as a positive correlation between the total cloud mass and atmospheric mixing. The cloud properties on the east and west limbs show distinct differences that increase with increasing equilibrium temperature. Cloud opacities are roughly constant across a broad wavelength range, with the exception of features in the mid-infrared. Forward-scattering is found to be important across the same wavelength range. Using the fully resolved size distribution of cloud particles as opposed to a mean particle size has a distinct impact on the resultant cloud opacities. The particle size that contributes the most to the cloud opacity depends strongly on the cloud particle size distribution. We predict that it is unlikely that silicate or titanium clouds are responsible for the optical Rayleigh scattering slope seen in many hot Jupiters. We suggest that cloud opacities in emission may serve as sensitive tracers of the thermal state of a planet’s deep interior through the existence or lack of a cold trap in the deep atmosphere.
Document type :
Journal articles
Complete list of metadata
Contributor : Nathalie POTHIER Connect in order to contact the contributor
Submitted on : Thursday, May 12, 2022 - 12:16:05 PM
Last modification on : Saturday, May 14, 2022 - 3:03:49 AM

Links full text




Diana Powell, Xi Zhang, Peter Gao, Vivien Parmentier. Formation of Silicate and Titanium Clouds on Hot Jupiters. The Astrophysical Journal, 2018, 860, ⟨10.3847/1538-4357/aac215⟩. ⟨insu-03666268⟩



Record views