The solid-state greenhouse effect: a model for dark Albedo features in the Martian polar regions
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
From a morphological and spectral study of dark albedo features in the Martian polar regions, a hypothesis is made that dark dune spots on Mars could indicate seepage flow of liquid water. In order to evaluate this hypothesis, the dark dune spots are studied both with regard for their seasonal time of appearance and composition. Using imagery from the HiRISE and CRISM instruments on the Mars Reconnaissance Orbiter, it is found that dark dune spots appear while CO2 ice still covers the surface. In order to account for this in the liquid water hypothesis, two theoretical models are constructed. One model is for the solid-state greenhouse effect in carbon dioxide ice and water-based snow packs. The other is for the solar radiation intensity on the Martian surface as a function of latitude and solar longitude. Additionally, an experiment is performed with the purpose of investigating the solid-state greenhouse effect in a Martian semi-analogous environment. From modeled results, it is found that sufficiently optically thin H2O snow/frost packs with low thermal conductance may allow salty liquid water even when the surface is encrusted with a layer of CO2 ice. Also, the appearance of particle sprays in the experiment may indicate the origin and nature of the bright halos and fans that sometimes appear in conjunction with dark dune spots and geysers. These would be deposited CO2 or H2O frost, that has been sprayed from the dark dune spots and geysers.
Place, publisher, year, edition, pages
Physics Chemistry Maths, Mars, dark albedo feature, dark dune spots, DDS, streak, solid-state greenhouse effect, CO2, polar cap, polar region, fans, pond, snow, frost, geyser, ice, astrobiology, exogeology, water, model, experiment.
Fysik, Kemi, Matematik
IdentifiersURN: urn:nbn:se:ltu:diva-57879ISRN: LTU-EX--10/057--SELocal ID: e7ea0d26-b8a3-44d0-873e-76707c8de503OAI: oai:DiVA.org:ltu-57879DiVA: diva2:1031267
Subject / course
Student thesis, at least 30 credits
Space Engineering, master's level
Validerat; 20101217 (root)2016-10-042016-10-04Bibliographically approved