Institute for Advanced Study Informal Astrophysics Seminar

Hot Jupiter atmospheres are thought to harbor relatively deep, statically stable radiative layers due to the intense irradiation they receive from their host stars. This reduces the planet's ability to cool and inhibits vertical transport of heat and momentum. We consider the effect of forced turbulent mixing in the radiative layer, which could be driven by atmospheric circulation or some other mechanism. Forced turbulence in the stable layer drives a downward flux of heat; depending on the strength of the mixing, the planet either slows its cooling or accumulates additional heat into the convective interior. In the latter case, the planet inflates until a balance is achieved between radiative cooling and heat burial by mixing. This process may contribute to the observed low densities of some "inflated" hot Jupiters. Additionally, we find the level of vertical mixing required to prevent separation of TiO from the atmospheric column is inconsistent with the assumption of a small internal entropy. This poses a significant challenge to the hypothesis that TiO is responsible for the inferred thermal inversions on some hot Jupiters.