EGU2020-21261
https://doi.org/10.5194/egusphere-egu2020-21261
EGU General Assembly 2020
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The ocean response to changes of the Greenland Ice sheet in a warming climate

Marianne S. Madsen1, Shuting Yang1, Christian Rodehacke1,2, Guðfinna Aðalgeirsdóttir3, Synne H. Svendsen1, and Ida Margrethe Ringgaard1
Marianne S. Madsen et al.
  • 1Danish Meteorological Institute, Denmark
  • 2Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Germany
  • 3University of Iceland, Iceland

During recent decades, increased and highly variable mass loss from the Greenland ice sheet has been observed, implying that the ice sheet can respond to changes in ocean and atmospheric conditions on annual to decadal time scales. Changes in ice sheet topography and increased mass loss into the ocean may impact large scale atmosphere and ocean circulation. Therefore, coupling of ice sheet and climate models, to explicitly include the processes and feedbacks of ice sheet changes, is needed to improve the understanding of ice sheet-climate interactions.

Here, we present results from the coupled ice sheet-climate model system, EC-Earth-PISM. The model consists of the atmosphere, ocean and sea-ice model system EC-Earth, two-way coupled to the Parallel Ice Sheet Model, PISM. The surface mass balance (SMB) is calculated within EC-Earth, from the precipitation, evaporation and surface melt of snow and ice, to ensure conservation of mass and energy. The ice sheet model, PISM, calculates ice dynamical changes in ice discharge and basal melt as well as changes in ice extent and thickness. Idealized climate change experiments have been performed starting from pre-industrial conditions for a) constant forcing (pre-industrial control); b) abruptly quadrupling the CO2 concentration; and c) gradually increasing the CO2 concentration by 1% per year until 4xCO2 is reached.  All three experiments are run for 350 years.

Our results show a significant impact of the interactive ice sheet component on heat and fresh water fluxes into the Arctic and North Atlantic Oceans. The interactive ice sheet causes freshening of the Arctic Ocean and affects deep water formation, resulting in a significant delay of the recovery of the Atlantic Meridional Overturning Circulation (AMOC) in the coupled 4xCO2 experiments, when compared with uncoupled experiments.

How to cite: Madsen, M. S., Yang, S., Rodehacke, C., Aðalgeirsdóttir, G., Svendsen, S. H., and Ringgaard, I. M.: The ocean response to changes of the Greenland Ice sheet in a warming climate, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21261, https://doi.org/10.5194/egusphere-egu2020-21261, 2020

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