EGU21-15672, updated on 07 Aug 2023
https://doi.org/10.5194/egusphere-egu21-15672
EGU General Assembly 2021
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Timing, thresholds and processes for complete future Greenland deglaciation

Miren Vizcaino1, Michele Petrini1, Raymond Sellevold1, Sotiria Georgiou1, Laura Muntjewerf1, William Lipscomb2, and Gunter Leguy2
Miren Vizcaino et al.
  • 1Geoscience and Remote Sensing Department, Delft University of Technology, Delft, Netherlands (m.vizcaino@tudelft.nl)
  • 2Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, USA

The Greenland ice sheet is currently losing mass at a rate of 0.8 mm of global mean sea level rise (SLR) per year. Here, we simulate its future evolution under an idealized scenario of high greenhouse gas forcing (1% increase per year until four times pre-industrial CO2).  To this end, we use the newly, bi-directionally coupled Community Earth System Model version 2 and Community Ice Sheet Model version 2 (CESM2-CISM2, Muntjewerf et al, GRL, 2020), that includes an advanced calculation of the surface mass balance in the land component with elevation classes downscaling to CISM. Deglaciation rates increase from 2 mm SLR per year by simulation year 140 (or time of CO2 stabilization) to 7 mm SLR per year two centuries later as the ablation areas expand and net solar radiation and turbulent (latent, sensible) heat fluxes become the dominant energy sources for melt. The ice sheet retreats to an ice cap in the interior of the northern half of Greenland, that melts completely by simulation year 1,700. We compare the Greenland climate evolution with a CESM2 simulation with fixed topography, and evaluate the role of vegetation, clouds, precipitation, and surface energy fluxes on the relatively fast decay of the ice sheet. In addition, we use a set of CISM2 simulations forced with CESM2 SMB to estimate the global warming/forcing threshold for complete deglaciation.

How to cite: Vizcaino, M., Petrini, M., Sellevold, R., Georgiou, S., Muntjewerf, L., Lipscomb, W., and Leguy, G.: Timing, thresholds and processes for complete future Greenland deglaciation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15672, https://doi.org/10.5194/egusphere-egu21-15672, 2021.

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