EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Antarctic ice sheet response to AMOC shutdowns during the penultimate deglaciation

Maxence Menthon1, Pepijn Bakker1, Aurélien Quiquet2, and Didier M. Roche1,2
Maxence Menthon et al.
  • 1Vrije Universiteit Amsterdam, Faculty of Science, Department of Earth Sciences, Amsterdam, The Netherlands
  • 2Laboratoire des Sciences du Climat et de l’Environnement (LSCE), UMR8212, CEA/CNRS-INSU/UVSQ, Gif-sur-Yvette Cedex, France

According to geological records, the sea level during the Last Interglacial (∼ 129–116 ka) peaked 6 to 9 m higher than during the pre-industrial with a major contribution from the Antarctic ice sheet (Dutton et al. 2015). According to Clark et al. 2020, a longer period of reduced Atlantic Meridional Overturning Circulation (AMOC) during the penultimate deglaciation compared to the last deglaciation could have led to greater subsurface warming and subsequent larger Antarctic Ice Sheet retreat.

Here we study the response of the Antarctic ice sheet to climate forcing with a forced AMOC shutdown at different timing and duration during the penultimate deglaciation (∼ 138–128 ka). The simulations are done with the Earth System Model of Intermediate Complexity iLOVECLIM (Roche et al. 2014) and the ice sheet model GRISLI (Quiquet et al. 2018), using the recently implemented sub-shelf melt module PICO (Reese et al. 2018). In the present simulations the GRISLI is forced with the iLOVECLIM simulations and is a step towards a fully coupled climate - ice sheet set up to take into account the climate - ice sheet interactions in a physical way.

We hypothesize that both the duration and timing of reduced AMOC can significantly affect the sensitivity of the Antarctic Ice Sheet. A longer period of AMOC reduction will lead to a larger subsurface warming in the Southern Ocean and subsequently a larger ice sheet retreat. On the other hand, an AMOC reduction earlier (later) in the deglaciation implies that the ice sheet that is affected by this subsurface warming is still fairly large (already small). We will discuss both the individual as well as combined effect of duration and timing on the ice sheet evolution.

How to cite: Menthon, M., Bakker, P., Quiquet, A., and Roche, D. M.: Antarctic ice sheet response to AMOC shutdowns during the penultimate deglaciation, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-11678,, 2023.

Supplementary materials

Supplementary material file

Comments on the supplementary material

to access the discussion