Ocean as the main driver of Antarctic ice sheet retreat during the Holocene
SWINGEDOUW, Didier
Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
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Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
SWINGEDOUW, Didier
Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique [CERFACS]
MARTI, Olivier
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Glaces et Continents, Climats et Isotopes Stables [GLACCIOS]
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Glaces et Continents, Climats et Isotopes Stables [GLACCIOS]
MASSON-DELMOTTE, Valérie
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Glaces et Continents, Climats et Isotopes Stables [GLACCIOS]
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Glaces et Continents, Climats et Isotopes Stables [GLACCIOS]
BRACONNOT, Pascale
Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics [MERMAID]
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Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] [LSCE]
Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics [MERMAID]
Langue
EN
Article de revue
Ce document a été publié dans
Global and Planetary Change. 2018, vol. 166, p. 62-74
Résumé en anglais
Ocean-driven basal melting has been shown to be the main ablation process responsible for the recession of many Antarctic ice shelves and marine-terminating glaciers over the last decades. However, much less is known about ...Lire la suite >
Ocean-driven basal melting has been shown to be the main ablation process responsible for the recession of many Antarctic ice shelves and marine-terminating glaciers over the last decades. However, much less is known about the drivers of ice shelf melt prior to the short instrumental era. Based on diatom oxygen isotope (δ18Odiatom; a proxy for glacial ice discharge in solid or liquid form) records from western Antarctic Peninsula (West Antarctica) and Adélie Land (East Antarctica), higher ocean temperatures were suggested to have been the main driver of enhanced ice melt during the Early-to-Mid Holocene while atmosphere temperatures were proposed to have been the main driver during the Late Holocene. Here, we present a new Holocene δ18Odiatom record from Prydz Bay, East Antarctica, also suggesting an increase in glacial ice discharge since ~4500 years before present (~4.5 kyr BP) as previously observed in Antarctic Peninsula and Adélie Land. Similar results from three different regions around Antarctica thus suggest common driving mechanisms. Combining marine and ice core records along with new transient accelerated simulations from the IPSL-CM5A-LR climate model, we rule out changes in air temperatures during the last ~4.5 kyr as the main driver of enhanced glacial ice discharge. Conversely, our simulations evidence the potential for significant warmer subsurface waters in the Southern Ocean during the last 6 kyr in response to enhanced summer insolation south of 60°S and enhanced upwelling of Circumpolar Deep Water towards the Antarctic shelf. We conclude that ice front and basal melting may have played a dominant role in glacial discharge during the Late Holocene.< Réduire