Observations of the highly-eccentric ( e \sim 0.9 ) hot-Jupiter HD 80606b with Spitzer have provided some of best probes of the physics at work in exoplanet atmospheres .
By observing HD 80606b during its periapse passage , atmospheric radiative , advective , and chemical timescales can be directly measured and used to constrain fundamental planetary properties such as rotation period , tidal dissipation rate , and atmospheric composition ( including aerosols ) .
Here we present three-dimensional general circulation models for HD 80606b that aim to further explore the atmospheric physics shaping HD 80606b ’ s observed Spitzer phase curves .
We find that our models that assume a planetary rotation period twice that of the pseudo-synchronous rotation period best reproduce the phase variations observed for HD 80606b near periapse passage with Spitzer .
Additionally , we find that the rapid formation/dissipation and vertical transport of clouds in HD 80606b ’ s atmosphere near periapse passage likely shapes its observed phase variations .
We predict that observations near periapse passage at visible wavelengths could constrain the composition and formation/advection timescales of the dominant cloud species in HD 80606b ’ s atmosphere .
The time-variable forcing experienced by exoplanets on eccentric orbits provides a unique and important window on radiative , dynamical , and chemical processes in planetary atmospheres and an important link between exoplanet observations and theory .