Articles | Volume 7, issue 2
The Cryosphere, 7, 615–630, 2013
The Cryosphere, 7, 615–630, 2013

Research article 04 Apr 2013

Research article | 04 Apr 2013

Evidence and analysis of 2012 Greenland records from spaceborne observations, a regional climate model and reanalysis data

M. Tedesco1, X. Fettweis2, T. Mote3, J. Wahr4, P. Alexander1,5, J. E. Box6, and B. Wouters4,7 M. Tedesco et al.
  • 1The City College of New York, The City University of New York, New York, NY 10031, USA
  • 2University of Liege, Liege, Belgium
  • 3University of Georgia, Athens, GA 30602, USA
  • 4Department of Physics and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
  • 5The Graduate Center of the City University of New York, New York, NY, USA
  • 6The Ohio State University, Columbus, OH, USA
  • 7School of Geographical Sciences, University of Bristol, Bristol, UK

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 ∼2 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 (SMB) 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 associated with anomalies in the North Atlantic Oscillation (NAO), changes in surface conditions (e.g., albedo, surface temperature) and preconditioning of surface properties from recent extreme melting as major driving mechanisms for the 2012 records. Less positive if not increasingly negative SMB will likely occur should these characteristics persist.