The long-term future of the Antarctic ice sheet: Uncertainties in ice sheet-Earth system interactions

• Main Author: Coulon, Violaine
• Other Authors: Pattyn, Frank, Fripiat, François, Tison, Jean-Louis, Debaille, Vinciane, Fettweis, Xavier, Reese, Ronja
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universite Libre de Bruxelles 2022
• Subjects: Glaciologie; Géographie physique; Climatologie; Antarctica; Sea level; Ice-sheet model; Ice sheet; Antarctic; The Antarctic; West Antarctic Ice Sheet; East Antarctic Ice Sheet; Antarc*; Ice Sheet
• Online Access: http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/350956; https://dipot.ulb.ac.be/dspace/bitstream/2013/350956/3/Content.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/350956/7/Thesis_ViolaineCOULON_Chapter4.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/350956/9/ContratDiCoulon.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/350956/6/Thesis_ViolaineCOULON_Chapter3.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/350956/8/Thesis_ViolaineCOULON_Chapter5_and_appendices.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/350956/4/Thesis_ViolaineCOULON_Chapter1.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/350956/5/Thesis_ViolaineCOULON_Chapter2.pdf

The Antarctic ice sheet (AIS) is the largest and yet the most uncertain potential contributor to future sea-level rise. While recent satellite observations have highlighted that the AIS is currently losing mass at an accelerating rate, projections of the future evolution of the ice sheet in a warming climate remain highly uncertain. As future sea-level rise is probably one of the biggest threats imposed on us by climate change, predicting it with the lowest possible uncertainty is of capital societal importance. Uncertainties in the future evolution of the AIS can be explained, notably, by the fact that the ice sheet is capable of abrupt and self-sustained changes associated with several positive feedback mechanisms, especially in its marine areas, i.e. where the ice lies on bedrock below sea level. This is the case for most of the West Antarctic ice sheet (WAIS) as well as for some basins of the East Antarctic ice sheet (EAIS). The interactions between the ice sheet and its surrounding environment (namely the ocean, the atmosphere, and the solid Earth) have been shown to strongly influence its stability, more particularly by triggering or dampening the instabilities threatening the ice sheet. Despite the uncertainties, recent studies suggest that the WAIS will lose mass in the future and eventually (partially) collapse. The uncertainties pertain to when, and to whether the weak Earth structure beneath that area of the ice sheet may be a stabilising factor, as a rapid bedrock uplift in response to ice mass loss has been shown to delay or even limit mass loss. The fate of the EAIS is less clear. A pending question is: will the EAIS lose or gain mass in the future? More specifically, will the grounding line retreat in its marine basins, and if so, can the associated mass loss be compensated by sufficient mass gain due to increased snow accumulation in the interior of the ice sheet?In this thesis, we contribute to clarifying and providing new insights to these questions, and therefore on the long-term future of the ...