EGU2020-7454
https://doi.org/10.5194/egusphere-egu2020-7454
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Potential Tipping Points of Antarctic Ice Sheet Basins

Sainan Sun1, Frank Pattyn1, Gael Durand2, Lars Zipf1, Kevin Bulthuis1,3, Heiko Goelzer1,4, and Konstanze Haubner1
Sainan Sun et al.
  • 1Universite Libre de Bruxelles, Brussels, Belgium (sainsun@ulb.ac.be)
  • 2Institut des Géosciences de l’Environnement, Université Grenoble-Alpes/CNRS, France
  • 3Computational and Stochastic Modeling, Aerospace and Mechanical Engineering, Université de Liège
  • 4Institute for Marine and Atmospheric Research, Utrecht University, The Netherlands

Antarctica is loosing mass in an accelerating way and these losses are considered as the major source of sea-level rise in the coming centuries. Ice-sheet mass loss is mainly triggered by the decreased buttressing from ice shelves mainly due to ice-ocean interaction. This loss could be self-sustained in potentially unstable regions where the grounded ice lies on a bedrock below sea level sloping down towards the interior of the ice sheet, leading to the so-called marine ice sheet instability (MISI).
Recent observations on accelerated grounding-line retreat and insights in modelling the West Antarctica ice sheet give evidence that MISI is already on its way. Moreover, similar topographic configurations are also observed in East Antarctica, particularly in Wilkes Land. We present an ensemble of simulations of the Antarctic ice sheet using the f.ETISh ice-sheet model to evaluate tipping points that trigger MISI by forcing the model with sub-shelf melt pulses of varying amplitude and duration. As uncertainties in ice-sheet models limit the ability to provide precise sea-level rise projections, we implement probabilistic methods to investigate the influence of several sources of uncertainty, such as basal conditions. From the uncertainty analysis, we identify confidence regions for grounded ice interpreted as regions of the Antarctic ice sheet that remain ice-covered for a given level of probability. Finally, we discuss for each Antarctic basin the total melt energy needed to reach tipping points leading to sustained MISI. 

How to cite: Sun, S., Pattyn, F., Durand, G., Zipf, L., Bulthuis, K., Goelzer, H., and Haubner, K.: Potential Tipping Points of Antarctic Ice Sheet Basins, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7454, https://doi.org/10.5194/egusphere-egu2020-7454, 2020

How to cite: Sun, S., Pattyn, F., Durand, G., Zipf, L., Bulthuis, K., Goelzer, H., and Haubner, K.: Potential Tipping Points of Antarctic Ice Sheet Basins, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7454, https://doi.org/10.5194/egusphere-egu2020-7454, 2020

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