Monday

We present an overview of work being done to adapt the Unified Model, one of the most
sophisticated weather and climate models, into a flexible planet simulator for use
in the study of any exoplanet. We focus on two projects:

Clouds in hot Jupiters - recent HST observations have revealed a continuum in atmospheric composition from cloudy to clear skies. This transition does not correlate with
equilibrium temperature, suggesting a requirement for a more sophisticated cloud formation scheme than homogenous cloud growth. We conduct 3D simulations of cloud nucleation, growth, advection, evaporation and settling in the atmosphere of HD209458b using the cloud code DIHRT, coupled to the Unified Model. We explore cloud composition, structure and grain sizes, and highlight the importance of atmospheric dynamics seen in tidally locked hot Jupiters on the cloud evolution and distribution.

Climate of Proxima b - we present results of climate simulations of the newly discovered planet Proxima Centauri b, examining the responses of both an ‘Earth-like’ atmosphere
and simplified nitrogen and trace carbon dioxide atmosphere to the radiation likely
received. Overall, our results are in agreement with previous studies in suggesting
Proxima Centauri b may well have surface temperatures conducive to the presence of liquid water. Moreover, we have expanded the parameter regime over which the planet may support liquid water to higher values of eccentricity and lower incident fluxes, guided by
observational constraints. Finally, we present planetary emission and reflectance
spectra, highlighting signatures of gases vital to the evolution of life on Earth.