Monday 15 Feb 2016: Condensation and climate dynamics in exoplanet atmospheres (Joint Astrophysics & GAFD Seminar)
Prof. Raymond Pierrehumbert - University of Oxford
Condensible substances are ubiquitous in planetary atmospheres, ranging from cryogenic ices to vapors of substances like enstatite that would be normally considered “rocks” on Earth. All of these substances can form condensate inventories at a planet’s surface, which take the form of glaciers or oceans, but condensation is an important factor in climate dynamics even when there is no condensible reservoir at the planet’s surface, or if the planet has no distinct surface at all (as in the case of gas giants, or “gas midgets” like GJ1214b). In this talk, I will review the varied affects of condensible substances on the dynamics of planetary atmospheres, taking a broad view of what the condensible substance may be. Among other things, I will discuss the “fine tuning” needed to permit the existence of a liquid surface ocean. I will also discuss some of the novel features of nondilute atmospheres, in which the condensible substance makes up a substantial fraction of the mass of the atmosphere.