Less Arctic sea ice both snows and melts Greenland
Losing Arctic sea ice in a +2 °C world adds winter snow to Greenland but more than offsets it with extra summer melt.
Source
Influence of Arctic sea-ice loss on the Greenland ice sheet climate
Study at a glance
- Design
- Computational / modelling — Two 100-member CESM2 ensembles prescribing preindustrial vs +2 °C Arctic sea ice/SST
- N
- N=100 · 100 one-year ensemble members per ice state (April 2000–May 2001)
- Population
- Greenland Ice Sheet surface mass balance under prescribed Arctic sea-ice loss
- Outcome
- Winter snowfall gains vs larger summer melt response to Arctic sea-ice loss
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Two 100-member CESM2 ensembles (April 2000–May 2001) prescribed pre-industrial versus +2 °C Arctic sea-ice concentration and in-Arctic SSTs from CMIP5, then computed Greenland SMB from snowfall, melt, refreeze, and sublimation.
What they found
Arctic sea ice fell 19.0% in winter and 48.4% in summer (3.6 and 6.4 million km2). Winter SMB rose 23 ± 33 Gt year−1 from extra precipitation; summer SMB fell 33 ± 64 Gt year−1 as melt rose 36 ± 76 Gt year−1. Summer melt extent increased 3.5% and blocking days over Greenland rose about 25%.
The limits
What it doesn't show
One-year simulations cannot capture ice-dynamic discharge. Prescribed ice/SST omit full ocean coupling. Melt-response uncertainty (±64 Gt) is large. CESM2 overproduces liquid-containing Arctic clouds versus observations.
Key terms
- Surface mass balance (SMB)
- Snowfall plus refreeze minus melt and sublimation at the ice-sheet surface.
- Arctic amplification
- Faster Arctic warming than the global mean, here forced by sea-ice loss and warmer Arctic SSTs.
- Elevation classes
- Sub-grid height bins CESM2 uses to downscale temperature and radiation over Greenland’s steep margins.
Flashcards
Research intelligence for this paper
See its role on concept claims, tensions it is part of, placement history, and related discoveries.
Quiz yourself
Winter Arctic sea-ice area in the perturbation falls by about:
Common questions
Does sea-ice loss only melt Greenland?
No. Winter accumulation rises, but summer ablation rises more in the mean response.
How was the +2 °C ice state built?
CMIP5 models’ SIC/SST at 2 °C global warming were regressed to HadISST observations and prescribed in CESM2.
Why more melt in the south?
The margin already sits at 0 °C, so extra heat goes into melt and turbulent fluxes rather than warming the ice further.
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