Investigation of the effect of dissolved salts, soil layers, and wind on the evaporation rate of water on Mars

Laboratory simulation experiments have been performed to study the stability of water under martian conditions. The first chapter of this thesis is a background introduction into the history of Mars and a description of the evidence for past and present water on Mars. The second chapter describes experiments that were performed on low concentration brine solutions, but were never published. The rest of the thesis is submitted in thesis by publication format. Chapters three and four were published in Geophysical Research Letters and chapter five has been submitted to Mars Polar Science Special Edition of Icarus.; The experiments described in this thesis were performed in the planetary simulation chamber in the W.M. Keck Laboratory for Space Simulations at the Arkansas Center for Space and Planetary Sciences. By simulating the conditions on Mars, with the exception of the gravitational constant, we are able to accurately measure the evaporation and sublimation of water and water ice.; We measured the evaporation rates of low concentrations of a sodium chloride brine solution, the effect of temperature on eutectic solutions of sodium chloride and calcium chloride brines, the effect of a soil layer on the sublimation rate of ice, and the effect of wind on the sublimation of ice. The results for the evaporation of brine solutions and the results for the sublimation of ice under a soil layer agree very well with theoretical calculations using Fick's Law of Diffusion, as put forth by A.P. Ingersoll and C.B. Farmer, respectively. In contrast, the sublimation rate of ice under varied wind velocities did not agree with previous theory. Therefore, a new theoretical model was developed in order to accurately describe the effect of increasing wind velocity on sublimation rates. The new theoretical model agreed extremely well with experimental data.; In performing these experiments, we are better able to understand the behavior of water under martian condition and can be used to determine under what conditions liquid water could exist and how long it would survive under the current environment on Mars. The implications relate to the formation of geologic features such as gullies and the possibility of life on Mars.