Master thesis defence by Bo Høegh Frederiksen – Niels Bohr Institute - University of Copenhagen

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Master thesis defence by Bo Høegh Frederiksen

A Radiative-Convective Model for the Atmosphere of Mars

The surface of Mars is covered by numerous valley networks thought to have been formed by flowing water around 3.9 billion years ago.
In this thesis it is studied whether Mars could have had an atmosphere dense enough to sustain liquid water on the surface.
This is done by developing a one dimensional radiative-convective (RC) model for the atmosphere on Mars in order to understand the conditions under which there could have been liquid water on the surface of early Mars.

An analysis of the absorption coefficient, κ, is presented. It is shown that by including an approximation of the absorption coefficient with a correlated κ- distribution the computation time of the model can be reduced significantly compared to line-by-line calculations.

Unfortunately, the attempt to make such a model was unsuccessful, so the project was abandoned in favour of a different approach. Focus was therefore changed to concentrate on what results others have achieved.

Several models, with increasing complexity, were studied. From a simple model based on pure RC balance to a more advanced RC model which includes clouds with IR scattering.
The results of these models indicate that early Mars with a surface pressure of 2 bar would have had a surface temperature around 245~K.
Radiative equilibrium alone would therefore not have been able to sustain an active water cycle.

Supervisor: Ass. professor Peter Ditlevsen, Centre for Ice and Climate