Thesis Results at LPSC 2012


Alejandro Soto


March 30, 2012

View from the back of the room at an LPSC session. Image: Alejandro Soto

One of my thesis chapters discusses the climate dynamics of atmospheric collapse on Mars. Although I am still working on submiting a version of this chapter to a peer-review journal, I thought that the Lunar and Planetary Science Conference (LPSC) would be a good place to present the results. Since the work would be difficult to squeeze into the LPSC standard 12-minute talk, I chose to present the work as a poster.

What is atmospheric collapse? If the temperature at any point in an atmosphere becomes colder than the condensational temperature of the primary constituent of the atmosphere, then that primary consituent condenses or deposits (basically, the bulk atmosphere ‘snows out’). “Atmospheric collapse” is the term used by many in the planetary atmosphere community to describe this phenomena. For Mars, the primary constituent of the atmosphere is carbon dioxide. For the current global mean surface pressure of Mars, which is around 6 millibars, the condensation temperature of carbon dioxide gas is ~148 K. Therefore, if the atmospheric temperature ever dipped below ~148 K, at that location the carbon dioxide would condense as ice. Thus, there would be atmospheric collapse.

Previously, scientists had hypothesized that the Martian atmosphere may have collapsed at some time in its past. Due to the large variations in the Martian orbital elements, it is possible that Mars experienced the right conditions to initiate the collapse of the atmosphere. The previous work used one dimensional and two dimensional climate models to investigate the stability of the Martian atmosphere. I have continued this line of research by using a general circulation model to investigate atmosphere collapse.

The presentation of the poster went well. Some of my colleagues were very interested in the work, and some great discussions were had.

Update: The paper on this topic was published in Icarus.