The Anthropocene transition in two coastal ice cores from Dronning Maud Land (East Antarctica): paleoclimatic trends, cycles, and drivers

• Main Author: Wauthy, Sarah
• Other Authors: Pattyn, Frank, Tison, Jean-Louis, Fripiat, François, Mattielli, Nadine, Stenni, Barbara, Matsuoka, Kenichi, Goosse, Hugues
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universite Libre de Bruxelles 2024
• Subjects: Glaciologie; ice cores; surface mass balance (SMB); paleo-proxies; Antarctica; Antarc*; Antarctic; Dronning Maud Land; East Antarctica; ice core; Ice Sheet
• Online Access: http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/375719; https://dipot.ulb.ac.be/dspace/bitstream/2013/375719/6/WauthySarah_PhD_Thesis.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/375719/5/WauthySarah_PhD_Open.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/375719/4/WauthySarah_PhD_Restreint.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/375719/3/WauthySarah_PhD_Thesis_Content.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/375719/7/ContratdiWauthy.pdf

The Antarctic Ice Sheet (AIS) is recognized as the largest potential contributor to future sea level rise, although its contribution remains the most uncertain. One of the main factors influencing future AIS mass changes is the surface mass balance (SMB). Due to its large spatial and temporal variability, as well as the multitude of processes driving it, the SMB is characterized by significant uncertainties. To mitigate these uncertainties, ice core analysis has proven to be an essential tool, offering insights into past conditions and improved simulations of Antarctica's future impact on sea level. This thesis aims to contribute novel field observations and advance understanding of SMB and environmental paleo-proxies, including their spatial and temporal variability and the processes driving them, during the Anthropocene transition.New insights into the evolution of SMB and environmental paleo-proxy are provided since the late 18th century, through the analysis of the FK17 and TIR18 ice cores drilled in coastal Dronning Maud Land. The analyses reveal pronounced spatial and temporal variability in both SMB and environmental proxies, with contrasting trends and long-term variability. This underscores the necessity to elucidate the processes at play and emphasizes the complexity of Antarctic climate dynamics.The temporal and spatial variability of SMB and paleo-proxy records is investigated, as well as the processes influencing them, for both our cores and IC12 which is situated in close proximity. The evaluation of the spatial and temporal representativeness of the ice core-derived SMB indicates that ice cores accurately estimate SMB on multiannual to decadal time scales. Regional snowfall-driven processes and local wind-driven erosion mechanisms are also shown to impact the SMB across ice rises, with ice core-derived SMB consistently lower than the average value calculated over the entire ice rise. The study of the spatial variability at the kilometer scale using five shallow cores suggests that differences in ...