Description du projet
La glace de mer dans le nord-ouest de l’Atlantique et son rôle dans l’effondrement des calottes glaciaires
Quel est le rôle de la glace de mer dans le système climatique? La perte actuelle de glace de mer affecte-t-elle les calottes glaciaires du Groenland? La réponse à ces questions réside dans la compréhension de la réaction des calottes glaciaires passées au changement climatique. Le projet IceLab, financé par l’UE, vise à étudier les associations entre la glace de mer, la circulation océanique, le réchauffement du sous-sol et l’effondrement des calottes glaciaires dans la mer du Labrador. L’objectif consiste à comprendre l’importance de la glace de mer dans la stabilité des calottes glaciaires. La méthodologie sera basée sur une approche intégrée de géochimie organique et inorganique combinée avec des techniques de datation et de corrélation de pointe. À terme, le projet contribuera à améliorer les prévisions de perte de masse des calottes glaciaires du Groenland.
Objectif
Northern hemisphere ice sheets are particularly vulnerable to climate change as the Arctic is warming twice as fast as the rest of the planet. Scenarios of future ice sheet stability, however, are associated with significant uncertainty, due to a lack of understanding of the relevant internal climate feedbacks. These processes involve ocean-ice sheet interactions and the effects of sea ice on the terrestrial cryosphere. With increased societal concerns over rising sea levels, it is more than ever important to understand the implications of climate change for ice sheet stability. The key lies in understanding the response of past ice sheets to climate change.
Prominent episodes of past ice-sheet collapse are so-called Heinrich events during the last glacial period, originating in Hudson Strait. While modelling studies have long hinted at the importance of sea ice in the Labrador Sea for subsurface warming and ocean induced melting during Heinrich events, this has not been shown using proxy methods. My project will investigate the links and feedbacks of sea ice, ocean circulation, subsurface warming, and ice-sheet collapse in the Labrador Sea to determine the role of the coupled cryosphere-ocean system for ice sheet stability across. Additionally, the effect of enhanced freshwater discharge on the system will be documented and a spatial-temporal map of North Atlantic sea ice dynamics across Heinrich events will be constructed. I will apply an integrated approach of organic and inorganic geochemistry, using sea-ice biomarkers, foraminiferal isotopes, and foraminiferal trace metals (i.e. Mg/Ca) in combination with state-of-the-art dating and correlation techniques. The new records will provide important clues with respect to a potential oceanic trigger of Hudson Strait iceberg surges during Heinrich events as well as advancing our understanding of the coupled cryosphere-ocean system, vital to accurately predict mass loss from the Greenland ice sheet in the future.
Champ scientifique
- natural sciencesearth and related environmental sciencesgeochemistry
- natural sciencesphysical sciencesastronomyplanetary sciencesplanets
- natural sciencesearth and related environmental sciencesatmospheric sciencesclimatologyclimatic changes
- natural sciencesearth and related environmental sciencesphysical geographyglaciology
Mots‑clés
Programme(s)
Régime de financement
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinateur
8000 Aarhus C
Danemark