A funded PhD opportunity is available to study heat and water vapor transport in the snow microstructure at the Snow Research Center, CEN/CNRM/Météo-France - CNRS, Grenoble, France (https://www.umr-cnrm.fr/spip.php?rubrique85) in collaboration with the Takuvik Joint International laboratory / Université Laval – CNRS, Québec, Canada (http://www.takuvik.ulaval.ca/index.php). The PhD starting fall 2019 is fully funded including 3 years of salary, mission costs and expenses for the experimental and numerical work.
Snow is at the interface between the atmosphere and the continental and oceanic surfaces of high latitudes and significantly affects their energy and water budgets. In particular, the snow thermally insulates the surfaces it covers. This insulating power is quantified by the snow thermal conductivity, a property which is difficult to measure reliably and continuously in remote areas such as the Arctic. Besides, the temperature gradient typically observed in arctic and sub-arctic snowpacks leads to a vertical flux of water vapor that transfers this compound from the soil and snowpack to the atmosphere. This essential process in the hydrological budget of cold regions is for the moment inadequately quantified. Recent developments in microstructural imaging and analysis of snow provide a detailed understanding of the phenomena of heat and matter transport in snow. This opens up important possibilities to evaluate measurement and modeling techniques related to these processes and finally to parameterize the physical models of snow and climate more precisely. This PhD project aims to improve the understanding and quantification of : (1) heat transport processes when measuring the thermal conductivity of snow by heated needle method. This method, which is the only one currently applicable in automatic mode, is suspected to present artifacts which need to be quantified and corrected by developing a suitable algorithm; (2) diffusion of water vapor in snow. This phenomenon involves sublimation-condensation processes of ice crystals which significantly contribute to the transfer but has not been quantified so far. Quantifying an apparent diffusion coefficient of water vapor is critical to simulate snow metamorphism, and thus all its physical properties, as well as the hydrological budget of snow-covered surfaces.
The project involves experimental work in a cold laboratory using X-ray tomography imaging of snow samples combined with measurements of thermal conductivity and mass transfer; and multi-physics numerical modeling with finite elements using 3D images of snow microstructure as input.
This opportunity is suited for a candidate with a quantitative background in (geo)physics, material sciences, applied mathematics, geoscience, or a related discipline. This project requires skills in numerical modeling and image processing. Field and cold-lab measurements are also part of the project and require specific motivations for cold and snow.
The Snow Research Center, CEN/CNRM/Météo-France – CNRS and its team “Snowpack” , where the PhD student will be based, is a world-class research team regarding the physical processes governing the time evolution of the snowpack and its interactions with the surrounding environment, in fields such as avalanche hazard forecasting or the role of snow in the climate system. The center has recently been equipped with new state of the art tomographic facilities. Overall, the snow community in Grenoble (gathered in OSUG) is very dynamic and provides an ideal breeding ground for innovative research. The Takuvik laboratory focuses on the impact of ongoing climatic and anthropogenic changes on Arctic marine and terrestrial ecosystems and geosystems. In particular, the lab has conducted major research concerning the thermal regime of permafrost and its interaction with snow cover properties. The PhD project will benefit from the expertise of these two labs with the supervision of F. Domine (UMI Takuvik), S. Morin (CEN) and P. Hagenmuller (CEN).
For more information and application, please contact us per e-mail ([hidden email]; [hidden email]; [hidden email]). Deadline for applications is May 15.
Pascal Hagenmuller, Florent Domine and Samuel Morin
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