In the framework of the Marie Sklodowska-Curie Innovative Training Network (ITN) DEEPICE, the
Laboratoire des Sciences du Climat et de l’Environnement, CEA / CNRS / Universities of Vesailles St Quentin and Paris Saclay looks for an
Early Stage Researcher (PhD student) in Climate Science to study the Evolution of snow and air circulating in snow beyond the surface of Antarctic ice sheet
In ice core, air bubbles are only trapped in the ice 60 to 120 m under the ice sheet surface at the bottom of the unconsolidated snow or firn. The composition of air and structure of snow is strongly modified during the processes of firn to ice densification and bubble closure entrapment with important consequences to understand ice core climatic and environmental records. In this phD project, we propose to explore two important effects:
-Thermal effect on the elemental and isotopic composition of the air
This effect will be studied using a firn air diffusion model constrained by new data (isotopic and elemental composition of inert gases and of oxygen) obtained through an Antarctica firn air pumping campaign.
-Modification of the snow structure down to the pore close-off due to snow metamorphism and snow densification
The understanding on how snow microstructure evolves with depth will be addressed using the detailed snowpack model Crocus. Using the snowpack model, we will first investigate the impact of insolation changes on surface snow microstructure. To support the modeling, observational constraints will be obtained from the Antarctica firn air campaigns with a focus here on the deeper part of the firn with analysis of air content and O2/N2 ratio, both in the closed and open porosity of the bubble close-off zone.
Etc.. see attachedESR11_positionannouncement-1.docx (22 Ko)