General Information

The Institute of Geosciences and Environment (IGE), Grenoble, France, is advertising a 2-year postdoctoral position.

The postdoc will be hired by CNRS and supervised by Nicolas Jourdain at IGE. The position will ideally start in October 2020.

We are looking for a highly motivated candidate with previous experience in physical oceanography, fluid dynamics, or similar. The objective of this postdoctoral work is to improve and develop parameterisations of ocean basal melting underneath Antarctic ice shelves.

Applicants should contact before June 15th.

Postdoctoral project and scientific context

The Antarctic ice sheet has been losing mass over the last few decades and has thus significantly contributed to global sea level rise. Warming of the oceanic sub-surface has caused an increase in melting under floating ice shelves, particularly in the Amundsen Sea (Jenkins et al. 2018). This has led to a retreat of the glaciers fronts and grounding lines (Mouginot et al. 2014; Rignot et al. 2014), and to the acceleration of their flow, which possibly indicates the premises of marine ice-sheet instabilities (Favier et al. 2014; Joughin et al. 2014). However, it remains very difficult to accurately represent the feedbacks between the climate system and the ice-sheet dynamics.

Although coupled ocean/ice-sheet models now start to be used, resolving ice-shelf cavities remains problematic because it requires a high-spatial resolution, which precludes the use of such coupled models for large ensemble simulations and long (centennial to millennial) climate runs. Using ocean melting parameterisations avoids this problem (e.g. Reese et al. 2018; Lazeroms et al. (2019)), but these have not been comprehensively evaluated against observations or realistic ocean simulations, and are so far among the largest sources of uncertainty on the future Antarctic contribution to sea level rise (Seroussi et al. 2020; Jourdain et al. 2020).

In this postdoctoral project, high-resolution regional ocean and ocean/ice-sheet simulations based on the NEMO ocean model (Mathiot et al. 2017) or the coupled ocean/ice-sheet NEMO/ElmerIce model (Favier et al., 2019) will be performed, with realistic ice-shelf cavities under various climatic forcings, including those expected under future climate conditions. The results will be used to evaluate, improve and develop parameterisations of ocean basal melting and the representation of ocean circulation and energy conservation in stand-alone models. These parameterisations will be tested in standalone ice-sheet models.

Local and international collaborations

IGE, previously known as LGGE, gathers renowned experts in Antarctic Sciences, on topics including paleo-climate from ice cores, glaciers and ice-sheet dynamics, physical oceanography and climate, as well as atmosphere and snow physics (among other fields). The modelling work will be carried out in close collaboration with NEMO experts at IGE (Pierre Mathiot, Julien Le Sommer, Jean-Marc Molines) and in France (NEMO team at LOCEAN-IPSL in Paris) and with Elmer/Ice experts at IGE (Fabien Gillet-Chaulet, Olivier Gagliardini, Gaël Durand).

This postdoctoral position is funded by the European Commission through the PROTECT H2020 project (Sep. 2020 - Aug. 2024). PROTECT gathers 26 international partners and aims to project the glaciers and ice sheets contribution to sea-level rise, and to assess local implications. This project will be a great opportunity for the postdoc to develop an international network in the topics of ocean, cryosphere and sea-level.