Description du sujet de thèse

The Greenland and Antarctic ice sheets are currently losing mass at an accelerating pace, making a significant contribution to global sea-level rise. This ice loss is today one of the main uncertainties in future sea-level projections. The Antarctic case, and particularly West Antarctica, is crucial because this region is potentially subject to internal dynamic instability (marine ice sheet instability). If such a process were to be triggered, it could contribute more than one meter to sea-level rise by the end of the century, making it a major concern for human societies and coastal ecosystems.
Projections of ice sheet evolution rely in particular on model intercomparison exercises organized within the framework of the ISMIP (Ice Sheet Model Intercomparison Project) initiative, in connection with international climate model assessment cycles (CMIP). The ISMIP6 project provided essential information that fed into the projections compiled by the IPCC in its 6th Assessment Report (AR6). The design of the new exercise, ISMIP7, has just begun and will be a decisive source of information for the next IPCC Assessment Report (AR7). The proposed PhD is part of this context and will directly support the French contribution, using the Elmer/Ice model, to ISMIP7.
The doctoral project will focus on three main research axes:
1. Evaluate and improve ice sheet models: propose original analyses to test model robustness, for example by studying the spread of results from different ice sheet models on comparable topographic configurations, in order to identify sources of uncertainty and possible improvements.
2. Contribute to ISMIP7 Antarctica experiments: carry out simulations with the Elmer/Ice model, actively participate in the analysis of multi-model results, and strengthen the visibility of the French contribution within the international effort.
3. Explore extreme Antarctic contribution scenarios: design and implement specific experiments aimed at evaluating the 'high-end' of projections, i.e. the highest possible contributions to sea-level rise. This will notably involve developing in Elmer/Ice a realistic moving calving-front module, beyond tests already conducted on idealized geometries (e.g., CalvingMIP), for large-scale applications.
This PhD will therefore contribute to improving our understanding of the uncertainties associated with ice sheet dynamics and to providing more robust and useful projections for future international climate and sea-level assessments.

Contexte de travail

The Institute of Environmental Geosciences (IGE) is a public research laboratory under the supervision of CNRS, IRD, INRAE, Université Grenoble Alpes (UGA) and Grenoble-INP. It conducts research on climate change and human impacts on our planet in polar, mountain, and intertropical regions, which are particularly sensitive and of major societal importance.
The laboratory has around 350 members, including 180 permanent staff (researchers, professors, engineers, technicians, and administrative personnel) and around 180 non-permanent staff (PhD students, postdocs, and fixed-term contracts). Each year, the laboratory hosts around 120 interns and visiting scientists. IGE is located across four buildings on the Grenoble University campus (Glaciology building, OSUG-B, Maison Climat Planète, and INRAE-Grenoble Saint Martin d'Hères).
The PhD student will conduct their research within the CryoDyn team at IGE and will be supervised by Gaël Durand and Cyrille Mosbeux.
This recruitment takes place within the TRACCS research program (Transforming Climate Modeling for Climate Services, https://climeri-france.fr/pepr-traccs/), which brings together the French climate modeling community. Its activities cover fundamental understanding of climate change and its impacts, extending to the development of prototype climate services co-designed by stakeholders and climate modeling experts. The goal is to accelerate the development of climate models to meet societal expectations for climate action, particularly in the area of adaptation to future climate change.
The program is structured into 10 targeted projects and one governance project, and will be complemented by projects responding to calls for proposals. It has a budget of €51 million over 10 years. It is co-led by CNRS and Météo-France, with 7 other academic partners. Governance and targeted project activities will mainly be conducted in the Paris region (laboratories of the Institut Pierre-Simon Laplace (IPSL)), in Toulouse (CNRM and other Météo-France entities, CERFACS), and in Grenoble (IGE).
The PhD candidate will be associated with the targeted ISClim project (Polar Ice Sheets in the Climate System – addressing high-end sea-level scenarios) of TRACCS (https://pepr-traccs.fr/projet/pc9-isclim/). ISCLIM aims to study the evolution of ice sheets and their interactions with the climate system, with a particular focus on better constraining projections of their contribution to sea-level rise and the impacts on other components of the climate system. The candidate will also work in close collaboration with the international community of ice sheet modelers within the ISMIP7 initiative (https://www.ismip.org).
Further details on ADUM: https://adum.fr/as/ed/voirproposition.pl?langue=&site=edtue&matricule_prop=57520

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.