Research engineer in numerical modelling (M/F)

Job Description

Missions

Despite coordinated international efforts and steady progress in ice sheet modelling, projecting future sea level rise remains a major scientific challenge. Current estimates for the year 2300 range from 0.5 meters to over 15 meters (IPCC, 2023). This wide uncertainty stems in part from our limited understanding of key physical processes. The numerical representation of these processes – coupled with the diverse timescales involved – poses significant challenges to the robustness of both future projections and past reconstructions.

At the Laboratoire des Sciences du Climat et de l'Environnement (LSCE), we develop the versatile ice sheet model GRISLI (Quiquet et al., 2018). GRISLI is used to simulate the future evolution of the Greenland and Antarctic ice sheets on centennial timescales (e.g., Quiquet and Dumas, 2021) and to reconstruct paleo-ice sheets over longer periods (van Aalderen et al., 2024). The model has also been recently adapted to study extraterrestrial planets (Schmidt et al., 2024).

This open position focuses on addressing long-standing challenges in ice sheet modelling, including grounding line dynamics (ice–ocean interactions) and basal drag. While the role will involve numerical development, the specific missions and objectives will be tailored to the candidate's profile – whether as a research scientist or a research engineer.
A primary goal is to improve the model's representation of sub-grid scale processes, either through grid refinement (zooming) or machine learning techniques. Implementations will be evaluated using reference test cases. For candidates with a research-oriented profile, the focus will be on revisiting future projections and investigating documented past ice sheet collapses. For those with a more technical background, the emphasis will be on improving model performance and automating spin-up methodologies.

This position is part of the TRACCS-PC9-ISCLIM project, which aims to study the evolution of polar ice sheets, refine their contribution to sea level rise, and explore their interactions with other components of the climate system. The successful candidate will collaborate closely with a team of engineers and researchers involved in the ISCLIM project.

Activity

The recruited Research Engineer will contribute to the following activities:

Model Development and Numerical Stability
• Implement sub-grid physics and/or parameterizations.
• Ensure numerical stability through experiments on idealized test cases.

Simulation and Evaluation
• Conduct simulations on national supercomputers and produce diagnostics to evaluate the model and validate new developments.

Code Optimization and Modernization
• Parallelize the code using MPI and OpenMP.
• Modernize the code architecture (Fortran).
• Improve the current initialization method (spin-up) based on velocity inversion using iterative procedures.

Collaboration and Documentation
• Collaborate with the team of researchers and engineers within the ISCLIM project, participating in regular meetings to report progress.
• Produce technical documentation for developments and provide user support (RE).
• Possibility to publish methodological advancements in dedicated journals (e.g., Geoscientific Model Development).

Your Profil

Skills

Scientific and technical requirements

• Msc. in geoscience or computer science or Phd. in glaciology;
• Proficiency in Fortran programming language or other structured language;
• Expertise in scientific computing and parallelization techniques;
• Proficiency in the Linux environment, shell scripts, etc.;
• Knowledge of climate data post-processing tools (netcdf, nco, cdo, etc.);
• Experience working on supercomputers (e.g. TGCC, IDRIS) would be an advantage;
• Project management methodology;
• English language: B2 to C1 (Common European Framework of Reference for Languages);
• Active involvement in the coordination and the animation of weekly meetings of the TRACCS-ISClim development group (~9 people);
• A PhD in the field of climate modelling or polar ice caps will be considered an advantage;
• Communication skills (written and oral) in English. Knowledge of French is not essential.

Your Work Environment

The TRACCS research programme brings together the French climate modelling community. Its activities cover the fundamental understanding of climate change and its impacts, and extend to the development of prototype climate services co-constructed by stakeholders and climate modelling experts. The challenge is to accelerate the development of climate models to meet society's expectations in terms of climate action, particularly in the area of adaptation to future climate change.

The position will be based at the Laboratory for Climate and Environmental Sciences (LSCE). The LSCE is a joint research unit (UMR 8212) between the CEA, the CNRS and the University of Versailles Saint-Quentin en Yvelines (UVSQ), located at l'Orme des Merisiers (Gif-sur-Yvette). It is part of the Institut Pierre Simon Laplace (IPSL), a federation of nine climate and environmental research institutes in the Paris region. The LSCE has around 320 researchers, engineers and administrative staff, including 150 permanent staff and around fifty PhD students. The person recruited will join the climate modelling team (CLIM) and will work closely with the GRISLI model developers

Compensation and benefits

Compensation

Since to 3237,95€

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions