Description du projet
Observations isotopiques pour la simulation du climat de l’Antarctique
La modélisation du système couplé complexe qui accélère la fonte de la glace antarctique est susceptible d’améliorer les projections sur l’élévation du niveau des océans. Toutefois, le manque de contraintes observationnelles directes nécessaires pour évaluer et améliorer les modèles climatiques mondiaux empêche toute simulation de l’avenir de la calotte glaciaire antarctique. Les signaux des isotopes contenus dans les carottes de glace de l’Antarctique peuvent enregistrer les variations climatiques, mais leurs performances restent limitées en ce qui concerne les simulations de processus pour les régions polaires. Le projet POLARISO, financé par l’UE, combine les avancées dans la modélisation du climat de l’Antarctique et les avancées en matière de mesures successives des isotopes de l’eau dans la vapeur d’eau et les précipitations en Antarctique afin d’assurer des fonctions de transfert solides entre les modèles climatiques et l’altération des isotopes de l’eau, ce qui permet de réaliser de nouvelles simulations climatiques impliquant des carottes de glace profondes et peu profondes de l’Antarctique.
Objectif
The rate of Antarctic ice loss is accelerating and reached 20% of the global sea level rise in 2012–2017. This acceleration is attributed to the coupling between atmosphere, ocean, and ice sheet dynamics. Intensive efforts are in place for modelling this complex coupled system, which is the only valid approach to improve sea level rise projections. However, the greatest uncertainty in simulating the future of the Antarctic ice sheet is due to the lack of direct observational constraints required to evaluate and improve global climate models. The isotopic signals contained in Antarctic ice cores have high potential to record the climate variability of recent centuries as water stable isotopes are tracers of the whole water cycle pathway. However, linking the isotopic signal to climate patterns requires to use isotope-enabled climate models, which are currently limited by their poor skills in simulating polar-specific processes.
The POLARISO project aims to overcome this major limitation by implementing water stable isotopes in a polar-oriented regional climate model, which will be evaluated with new isotope observations in Antarctica. We will then use the validated simulations to identify large scale drivers of the isotope variability at the Antarctic surface. This project is based on a synergy between advances in Antarctic climate modelling (PI) and advances in continuous measurements of water isotopes in water vapor and precipitation in Antarctica (host). The POLARISO project will provide robust transfer functions between climate modes and water isotope variability, which will open doors for new climate reconstructions based on water isotope measurements in Antarctic deep and shallow ice cores. It will also enable the PI to reach an independent leading position by developing an internationally unique expertise on polar regional modelling equipped with water isotopes, dedicated to model-data studies.
Champ scientifique
Programme(s)
Régime de financement
MSCA-IF-EF-ST - Standard EFCoordinateur
75794 Paris
France