Wednesday 17 Mar 2021: The atmospheric circulation and evolution of warm, hot, and ultra-hot Jupiters
Thaddeus Komacek -
Remote seminar 14:00-15:00
The atmospheres of hot gas giants that orbit close-in to their host star have been well characterized in the past decade through space-based observations with the Hubble and Spitzer space telescopes. Light curves of transiting hot Jupiters taken over a full orbital phase provide an avenue to constrain their climate and test models developed to understand their atmospheric dynamics. In this talk, I will discuss possible solutions to two puzzles about the atmospheric circulation and evolution of these hot gas giant planets. First, recent light curve observations of ultra-hot Jupiters with equilibrium temperatures in excess of 2200 K have found evidence for new physical processes at work in their atmospheres due to the dissociation of molecular hydrogen. I will discuss the observational differences between ultra-hot Jupiters and cooler gas giants, and describe theory for the mechanisms that impact the circulation of ultra-hot Jupiters. I will also present results from 3D general circulation modeling experiments that include the effects of hydrogen dissociation and recombination and compare these simulations to observations of KELT-9b, the hottest ultra-hot Jupiter discovered. Second, many hot and ultra-hot Jupiters are inflated, with anomalously large radii that can be up to twice as large as expected from standard evolutionary models. Understanding the anomalous radii of these transiting hot gas giant planets is a fundamental unsolved problem in planetary science. I will describe how recent observations of re-inflated warm Jupiters orbiting post-main-sequence stars and hot Jupiters orbiting main-sequence stars provide an avenue to determine the cause of radius inflation of hot and ultra-hot Jupiters. To do so, I will present evolution models studying the re-inflation of gas giants in order to determine how varying the depth and intensity of deposited heating affects the re-inflation of both warm and hot Jupiters. Lastly, I will show how TESS and PLATO observations of a large sample of re-inflated warm Jupiters can constrain the mechanism(s) causing the anomalous radii of gas giant planets.