Preprints
https://doi.org/10.5194/cp-2024-51
https://doi.org/10.5194/cp-2024-51
07 Aug 2024
 | 07 Aug 2024
Status: a revised version of this preprint is currently under review for the journal CP.

Northern Hemisphere ice sheets and ocean interactions during the last glacial period in a coupled ice sheet-climate model

Louise Abot, Aurélien Quiquet, and Claire Waelbroeck

Abstract. This study examines the interactions between the Northern Hemisphere ice sheets and the ocean during the last glacial period. We explore the consequences of an ocean subsurface warming on ice sheet dynamics and the associated feedbacks, using the climate model of intermediate complexity iLOVECLIM coupled with the ice sheet model GRISLI. Our study shows that amplified oceanic basal melt rates lead to significant freshwater release from both increased calving and basal melt fluxes. Inland, dynamic thinning occurs over the Eurasian and Iceland ice sheets, leading to destabilization, while the coasts of Greenland and the eastern part of the Laurentide ice sheet are thickening. There, the increased oceanic basal melt rates lead to a reduction in the thickness of the ice shelves and the ice flow at the grounding line, resulting in upstream accumulation. Nevertheless, the influx of fresh water temporarily increases sea-ice extent, reduces convection in the Labrador Sea, weakens the Atlantic meridional overturning circulation, lowers surface temperatures in the Northern Hemisphere and increases the subsurface temperatures in the Nordic Seas. The release of cold and fresh water leads to a decrease in ice sheet discharge (negative feedback) for the Greenland and Eurasian ice sheets. The Laurentide ice sheet is rather stable due to low background temperatures and salinity at shelf drafts in the Baffin Bay and Labrador Sea in the model. Still, we show that we are able to trigger a grounding line retreat by imposing ad-hoc oceanic melt rates (10 m/yr). However, continental ice loss stops as soon as we halt the perturbation. This study emphasizes the complex feedback mechanisms at the ocean-ice sheet interface, stressing the necessity for more accurately constrained model results to enhance our understanding of past changes and the predictions of future ice sheet behaviour and sea level rise.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Louise Abot, Aurélien Quiquet, and Claire Waelbroeck

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on cp-2024-51', Anonymous Referee #1, 14 Oct 2024
    • AC1: 'Reply on RC1', louise abot, 29 Nov 2024
  • RC2: 'Comment on cp-2024-51', Anonymous Referee #2, 01 Nov 2024
    • AC2: 'Reply on RC2', louise abot, 29 Nov 2024
Louise Abot, Aurélien Quiquet, and Claire Waelbroeck

Data sets

Source data of 'Northern Hemisphere ice sheets and ocean interactions during the last glacial period in a coupled ice sheet-climate model' Louise Abot, Aurélien Quiquet, and Claire Waelbroeck https://doi.org/10.5281/zenodo.12793237

Louise Abot, Aurélien Quiquet, and Claire Waelbroeck

Viewed

Total article views: 440 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
317 105 18 440 27 9 10
  • HTML: 317
  • PDF: 105
  • XML: 18
  • Total: 440
  • Supplement: 27
  • BibTeX: 9
  • EndNote: 10
Views and downloads (calculated since 07 Aug 2024)
Cumulative views and downloads (calculated since 07 Aug 2024)

Viewed (geographical distribution)

Total article views: 449 (including HTML, PDF, and XML) Thereof 449 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 11 Dec 2024
Download
Short summary
This modeling study examines how Northern Hemisphere ice sheets interacted with oceans during the last glacial period. Warmer ocean subsurface temperatures increase freshwater release, cooling the Northern Hemisphere and slowing the ocean circulation. Cold freshwater release slows ice discharges, revealing complex feedback at this interface. The study emphasizes the importance of additional modeling studies and observational comparisons to enhance understanding of past climate variability.