http://arxiv.org/abs/1510.03527
A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3-D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a ‘moist greenhouse’ explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing ‘inverse’ climate calculations to determine habitable zone boundaries using 1-D models.
J. Kasting, H. Chen and R. Kopparapu
Wed, 14 Oct 15
42/66
Comments: 4 Pages, 4 Figures, Accepted to the Astrophysical Journal Letters
You must be logged in to post a comment.