Abstract
In this talk I will discuss new insights into fundamental properties of both protoplanetary disks and clouds in extrasolar atmospheres from the microphysical perspective.
I will first report on our new set of models that reconcile theory with observations of protoplanetary disks and create a new set of initial conditions for planet formation models. The total mass available in protoplanetary disks is a critical initial condition for understanding planet formation, however, the surface densities of protoplanetary disks still remain largely unconstrained due to uncertainties in the dust-to-gas ratio and CO abundance. In our new modeling, we make use of recent resolved multiwavelength observations of disks in the millimeter to constrain the aerodynamic properties of dust grains, allowing us to infer total disk mass without an assumed dust opacity or tracer-to-H2 ratio.
Next, I will present the first application of a bin-scheme microphysical and vertical transport model to determine the size distribution of cloud particles in the atmospheres of hot jupiters and very low gravity brown dwarfs. Clouds on extrasolar worlds are seemingly abundant and interfere with observations; however, little is known about their properties. In our modeling, we predict particle size distributions from first principles and investigate how many of these objects’ interesting observational properties can be explained by clouds.
Finally, I will present new work that combines the microphysics of cloud formation in planetary atmospheres and our new models of protoplanetary disks to show that the observed depletion of CO in well-studied disks is consistent with freeze-out processes and that the variable CO depletion observed in disks can be explained by the processes of freeze-out and particle drift.