Baroclinic instability on Earth and Mars

In this thesis we study midlatitude atmospheric dynamics on Earth and Mars. The climate history of these planets is also discussed in this context. We extend theories of baroclinic eddies on Earth to Mars. For Earth, we focus on theories of baroclinic adjustment under the influence of different types of radiative forcing. We extend the theory to Mars' present atmosphere by exploring the connection between suspended dust, radiative forcing and baroclinic eddies. We also study the effects of condensation of CO2 for a hypothetical dense atmosphere on early Mars. We also present some preliminary results on the effects of water vapor condensation on Earth.; We examine implications for the dynamical behavior of the atmosphere of Mars under circumstances that may have occured early in the planet's history. We develop dynamical models under such conditions and explore the behavior of midlatitude storms. We discuss the implications of the modelled midlatitude dynamics for the overall climate of early Mars. We develop a parameterization for the effects of condensation of CO2. This parameterization is utilized in a quasi-geostrophic model as well as in a GCM. Results suggest that eddy properties may have been very different on early Mars, depending on whether it was relatively warm or cold.; We also develop models applicable to the present Martian atmosphere and to the Earth. The focus of these models is the effect of radiative forcing. We examine some major differences in the dynamics of the model resulting from the choice of radiation scheme. The model shows evidence of baroclinic adjustment, under circumstances representing Earth but not for Mars. Major differences in observed eddy behavior on Earth and Mars are attributed to the depth of radiative forcing. The interpretation of the model results is that baroclinic adjustment can occur in atmosphere that are convectively driven; where the static stability is small. For atmospheres in which the stability is radiatively dominated, there is no scope for baroclinic adjustment. We suggest that atmospheric stability on present Mars should be strongly effected by the vertical distribution of dust while on Earth it is controlled by the vertical distribution of water vapor.