Composition and distribution of clouds in hot Jupiters atmospheres

Wed, September 09, 2015

Over a large range of equilibrium temperatures clouds seem to dominate the transmission spectrum of hot Jupiters atmospheres but no trend allowing the classification of these objects have yet emerged. Recently observations of the light reflected by these planets provided insight on the cloud distribution on the dayside of these planets : for a handful of planets clouds seem more abundant on the western than on the eastern side of the dayside hemisphere and, more importantly, this asymmetry depends on the equilibrium temperature of the planet. 

Using state-of-the-art three dimensional models of hot Jupiters atmospheres I will show that longitudinal and latitudinal assyemtry in the cloud coverage is expected for these hot planets. Such an asymetry should directly affect the abundances retrieved from transmission and secondary eclipse spectra. The cloud asymetry on the dayside being a strong function of the condensation temperature of the cloud species, these models allow us to determine the main composition of the cloud material. In particular I will show that a transition from silicate to sulfide clouds is needed to explain the Kepler data.