Towards robust prediction of the dynamics of the Antarctic ice sheet: Uncertainty quantification of sea-level rise projections and grounding-line retreat with essential ice-sheet models

• Main Author: Bulthuis, Kevin
• Other Authors: Arnst, Maarten, Pattyn, Frank, Dewals, Benjamin, Ritz, Catherine, Soize, Christian, Tison, Jean-Louis
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universite Libre de Bruxelles 2020
• Subjects: Sciences exactes et naturelles; Glaciologie; Probabilités; Statistique appliquée; Uncertainty quantification; Probabilistic projections; Confidence sets; Essential ice-sheet models; Antarctic ice sheet; Quantification des incertitudes; Projections probabilistes; Régions de confiance; Modèles glaciologiques essentiels; Calotte polaire de l'Antarctique; Antarctic; The Antarctic; Antarc*; Ice Sheet
• Online Access: http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/301049; https://dipot.ulb.ac.be/dspace/bitstream/2013/301049/3/Thesis_Bulthuis.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/301049/4/Table_of_contents_Thesis_Bulthuis.pdf; https://dipot.ulb.ac.be/dspace/bitstream/2013/301049/5/ContratDiBulthuis.pdf

Recent progress in the modelling of the dynamics of the Antarctic ice sheet has led to a paradigm shift in the perception of the Antarctic ice sheet in a changing climate. New understanding of the dynamics of the Antarctic ice sheet now suggests that the response of the Antarctic ice sheet to climate change will be driven by instability mechanisms in marine sectors. As concerns have grown about the response of the Antarctic ice sheet in a warming climate, interest has grown simultaneously in predicting with quantified uncertainty the evolution of the Antarctic ice sheet and in clarifying the role played by uncertainties in predicting the response of the Antarctic ice sheet to climate change. Essential ice-sheet models have recently emerged as computationally efficient ice-sheet models for large-scale and long-term simulations of the ice-sheet dynamics and integration into Earth system models. Essential ice-sheet models, such as the fast Elementary Thermomechanical Ice Sheet (f.ETISh) model developed at the Université Libre de Bruxelles, achieve computational tractability by representing essential mechanisms and feedbacks of ice-sheet thermodynamics through reduced-order models and appropriate parameterisations. Given their computational tractability, essential ice-sheet models combined with methods from the field of uncertainty quantification provide opportunities for more comprehensive analyses of the impact of uncertainty in ice-sheet models and for expanding the range of uncertainty quantification methods employed in ice-sheet modelling. The main contributions of this thesis are twofold. On the one hand, we contribute a new assessment and new understanding of the impact of uncertainties on the multicentennial response of the Antarctic ice sheet. On the other hand, we contribute new methods for uncertainty quantification of geometrical characteristics of the spatial response of physics-based computational models, with, as a motivation in glaciology, a focus on predicting with quantified uncertainty the retreat ...