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.
Inspect source passages
Less Arctic sea ice both snows and melts Greenland
These passages occur verbatim in the stored paper text. They support the points listed below; they do not verify every statement in the explanation.
Each experiment has 100 one-year ensemble members.
To increase the robustness of our results, we analyze large ensembles (100 members per experiment).
Winter Arctic sea-ice area drops 19.0% and summer 48.4% in the perturbation.
The sea ice reductions in the Arctic (> 60 ∘ ) are 3.6 × 10 6 km 2 (19.0%) and 6.4 × 10 6 km 2 (48.4%) for winter and summer, respectively.
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
0 of 11 answers reviewed
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.
More on Ice sheets