Atmospheric Heat Engines on Earth and Mars

Abstract

The character of the Earth's atmospheric heat engine depends, inter alia, on the relatively tight linkage between surface fluxes of energy and of H20. On Mars, on the other hand, H2O-based latent heat fluxes are only a trivial fraction of total surface energy fluxes and the dominant component of the working fluid is CO2. These considerations are made quantitative through evaluation of ?, the equivalent temperature excess at the surface for a particular component of the working fluid. The very different values (and latitudinal distribution) of ? on the two planets signalize vividly their different meteorology. Preliminary study of the climatology of ? on Earth brings out, in particular, the tightness of the H20-energy linkage in the tropics.