Dynamique climatique côtière en région Antarctique au cours des 50 000 dernières années

• Main Author: Buiron, Daphné
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Joseph-Fourier - Grenoble I, Mr Jérôme Chappellaz
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2010
• Subjects: Paléoclimat; Antarctique; carottes de glace; méthane; datation; dynamique climatique à échelle millénnaire; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarc*; Antarctic; Antarctique*; ice core; Ross Sea
• Online Access: https://theses.hal.science/tel-00551793; https://theses.hal.science/tel-00551793v2/document; https://theses.hal.science/tel-00551793v2/file/buiron-manuscritthese-final.pdf

The global warming observed since the beginning of the last century, and mostly attributed to the significant greenhouse gases release produced by anthropogenic activities, induces different responses of the Earth climatic system. Forecasting of the future climate evolution requires the use of models where the reliability partly depends on tests that should be performed under various boundary conditions. In order to constrain the poorly-known parameters of these models, a well-adapted method is to conduct investigations on past climates. The TALDICE ice drilling project takes place within this general context. Its main objective aims for the improvement of our knowledge of the past climate variability recorded on the Antarctic continent, more particularly focusing on regional discrepancies and on the behavior of sites located at the edge of the East-Antarctic plateau, notably during rapid climatic variations. The deep ice drilling TALDICE project was conducted in Talos Dome in the Victoria Lands, close to the Ross Sea. In the course of this PhD work, we concentrated on the building of an accurate age scale for the TALDICE ice core, first based on methane and air isotopes measurements performed on the air contained in bubbles trapped inside the ice, and then from the use of various dating models, including a new inverse method which maximizes the consistency between stratigraphic markers and glaciological constraints. The TALDICE-1 age scale then created has enabled us 1) to show that the ice core climate record was usable without hiatus down to an age of 250.000 years before present-day, 2) to discuss the phase relationships between rapid climatic events recorded during the last deglaciation and the end of the last glacial period (Marine isotopic stage n°3) between TALDICE and other ice cores originally from both hemispheres. A multi-proxy analysis, completed with the use of simulations performed with a global atmosphere-ocean coupled climate model (the IPSL-CM4 model), has enabled us to come to the conclusion ...