Exploring feedbacks between heat conduction, vapor diffusion and settlement from a newly developed snowpack model

4 à 6 mois entre janvier et juin 2023

Faithful, dynamical modeling of the physical properties of snow is a prerequisite for a wide range of applications impacting human activities, such as avalanche hazard forecasting, water resources management or projections of future climate evolution. To address these needs, several one-dimensional snowpack models with various levels of complexity have been developed over the years. Yet, even in the most detailed models, some important processes with commonly accepted mathematical representation, such as water vapor diffusion, remain inadequately, if at all, implemented. This limitation is due to the numerical difficulties arising as the resulting mathematical model turns into a system of highly non-linear and highly-coupled partial differential equations. To tackle this challenge, we have developed a highly-modular finite-element program in which every step of the numerical formulation and resolution is coded internally, while taking particular care to ensure that mass and energy are conserved. This work is part of the European Research Council (ERC) project IVORI, which gathers a team of six enthousiastic snow scientists at CEN and involves major collaborations both on a national and international level (https://ivori.osug.fr/).
Our new model is now mature to address the problem of coupled heat and vapor diffusion together with settlement. The goal of this internship is to run the model on specific numerical experiments in order to get a better understanding of the feedbacks between these different processes. To this end, several numerical experiments will have to be designed. In a first time, the new model will be compared to those already available from numerical benchmarks based on published literature. Then, the model will be evaluated against observations obtained from laboratory experiments performed in cold room. Finally, if the two first steps are successfull, some ‘real-world’ application could be envisionned, whereby model outputs would be compared to in-situ observations performed on the experimental alpine site of Col De Porte.
The applicant is expected to have a general interest and some experience in programming and in the numerical simulation of physical systems. The selected candidate will join the collaborative working environnement of the IVORI team. She/he will also have the opportunity to take part to a few fieldwork days to collect data at Col De Porte.