Thanks go out to commenter Lanevn for bringing this to our attention.
Some of the data concerning last summer's impact on the Greenland ice sheet has been released in a first paper by M. Tedesco, X. Fettweis, T Mote, J. Wahr, P. Alexander, J. Box, and B. Wouters: Evidence and analysis of 2012 Greenland records from spaceborne observations, a regional climate model and reanalysis (PDF).
As it says on the Greenland Melting blog:
Overall, in 2012 ALL of the considered parameters (albedo, bare ice, surface mass balance, melting, total mass change, etc.) set a new record!
Records all around, not just for the Arctic sea ice. These two graphs say it all:
And this adapted version of a figure in the paper by Al Rodger (here's his website full of climate graphs):
Al writes: "I scaled the data off the graph & produced a graph of rate of mass loss which shows the year October 2011-September 2012 has smashed through the 500 Gt/year barrier with a value of 570 Gt/year."
Here's the paper's abstract:
A combined analysis of remote sensing observations, regional climate model (RCM) outputs and reanalysis data over the Greenland ice sheet provides evidence that multiple records were set during summer 2012. Melt extent was the largest in the satellite era (extending up to ~ 97% of the ice sheet) and melting lasted up to ~ two months longer than the 1979–2011 mean. Model results indicate that near surface temperature was ~ 3 standard deviations (σ) above the 1958–2011 mean, while surface mass balance was ~ 3σ below the mean and runoff was 3.9σ above the mean over the same period. Albedo, exposure of bare ice and surface mass balance also set new records, as did the total mass balance with summer and annual mass changes of, respectively, −627 Gt and −574 Gt, 2σ below the 2003–2012 mean.
We identify persistent anticyclonic conditions over Greenland [Chris Reynolds has written about this on the Dosbat blog, N.] associated with anomalies in the North Atlantic Oscillation (NAO), changes in surface conditions (e.g. albedo) and pre-conditioning of surface properties from recent extreme melting as major driving mechanisms for the 2012 records. Because of self-amplifying positive feedbacks, less positive if not increasingly negative SMB will likely occur should large-scale atmospheric circulation and induced surface characteristics observed over the past decade persist. Since the general circulation models of the Coupled Model Intercomparison Project Phase 5 (CMIP5) do not simulate the abnormal anticyclonic circulation resulting from extremely negative NAO conditions as observed over recent years, contribution to sea level rise projected under different warming scenarios will be underestimated should the trend in NAO summer values continue.
Again, the whole paper can be read here. Hopefully this doesn't get worse in years to come.