Institute for Advanced Study/Princeton University Joint Astrophysics Colloquium

On the present Earth, the primary condensible substance — water vapor — represents only a few percent of the mass of the atmosphere. While the effects of the latent heat of phase change are dynamically significant, the direct effects of mass loss are minimal, and in particular do not have to be taken into account in the energy or momentum budget of the atmosphere. In a wide variety of important planetary contexts, however, the condensible substance can make up a major fraction of atmospheric mass. This occurs for water vapor in the near-runaway states at the inner edge of the conventional habitable zone, and for carbon dioxide near the outer edge, but the situation arises in a wide variety of other planetary circumstances. In this talk I will present results from my ongoing project to develop an understanding of the fluid dynamics and climate physics of such objects.