Publication
Names
  • F. Grisolle
Title
Hydratation minérale à la surface de mars : Caractérisation spectroscopique, thermodynamique et application a la télédétection
Abstract
The current climate of Mars causes the formation of seasonal condensates on the surface of high-latitude regions during the polar night. This layer sublimates when exposed to sun in spring. Spatial instruments have enabled to study the spatial and temporal evolution and thermodynamic properties of ther CO2-mainly deposits. The aim of this thesis is to supplement this research by laboratory experimentation in order to improve the knowledge of the condensates properties and microphysical process. An experimental set-up, CarboNIR, has been conceived to manipulate analogous ices in controlled environment. The experiments on CO2, at equilibrium or nonequilibrium, create various grainsize (from about ten microns to several millimeters) and porosity (from 0 to 50% approximately) condensates. The corresponding near-infrared reflectance spectra show specific differences. Compact CO2 slab ices, transluscent or with highly transparency, can be formed by thermal metamorphism of porous snow or by direct condensation of gas. Thermal fluxes balance in the system highlights heat fluxes supplied by the set-up to the sample and the sublimation-condensation process ocurring in it, with matter and energy transfers through the porosity. Thermal and pressure constraints on the ice samples enable to determine the evolution according to of specific parameters, and therefore to comprehend the seasonal condensates microphysic evolution associated with local thermal conditions on Mars polar regions. Accuracy of radiative transfer models and GCM, as well as interpretation of Martian monitoring data will be improved by the confrontation with the experimental results.
Keywords
spectroscopy, thermodynamics, sample cell, spectro-gonio radiometer, bidirectional reflection, radiative transfer simulation, bidirectional reflectance spectra, visible, near-IR, thermal process, fluid process, condensation, sublimation, kinetic, grain size, molecular solid, ice, snow, CO2, Mars, surface
Content
instrument-technique, sample, material-matter, spectral data, thermodynamic data, planetary sciences
Document type
phd thesis
Year
2013
Pages
1 - 216
Pages number
216
Editor
IPAG
Publisher
Université Joseph Fourier
Publisher city
Grenoble, France
Publication state
published
Comments
20 December 2013