Radiative Hydrodynamics of Short Period Planets
Ian Dobbs-Dixon
Université McGill

Ubiquitous among observed extrasolar planetary systems, short-period gas-giant planets are intensely irradiated by their host star. The impinging stellar flux dominates the energy budget of their atmospheres, resulting in dramatic hydrodynamical flows. Ongoing transit observations of a number of these planets are beginning to constrain these flows through both spectral measurements and phase curves. Surprising features in both the inferred atmospheric structure and surface temperatures have challenged modeling efforts, requiring the introduction of new physics into fluid models. I will present results from global three-dimensional radiative hydrodynamical simulations of atmospheric circulation on close-in gas-giant planets. Three-dimensional simulations and the decoupling of the radiation and thermal energies have allowed us to address many of recent observations. The resulting flow patterns and energy redistribution efficiencies are sensitive functions of not only the irradiation but also of the interior structure, composition, planetary rotation rate, and atmospheric opacities. Coupling such models with the large diversity of observed planetary properties suggests that atmospheric dynamics may not only influence today's observables but may also play an important role in the overall evolution of the planet.

Date:	Jeudi, 6 novembre 2008
Time:	12:15
Where:	Université de Montréal
	Pavillon Roger-Gaudry, Local D-460
Contact:	Pierre Bastien