Mass balance and acceleration of the Greenland ice sheet, supplement to: Sasgen, Ingo; van den Broeke, Michiel R; Bamber, Jonathan L; Rignot, Eric; Sørensen, Louise Sandberg; Wouters, Bert; Martinec, Zdenek; Velicogna, Isabella; Simonsen, Sebastian B (2012): Timing and origin of recent regional ice-mass loss in Greenland. Earth and Planetary Science Letters, 333-334, 293-303

• Main Authors: Sasgen, Ingo, van den Broeke, Michiel R, Bamber, Jonathan L, Rignot, Eric, Sørensen, Louise Sandberg, Wouters, Bert, Martinec, Zdenek, Velicogna, Isabella, Simonsen, Sebastian B
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2012
• Subjects: International Polar Year 2007-2008 IPY; Greenland; Sandberg; Ice Sheet; International Polar Year; IPY; Sea ice
• Online Access: https://dx.doi.org/10.1594/pangaea.834956; https://doi.pangaea.de/10.1594/PANGAEA.834956

Within the last decade, the Greenland ice sheet (GrIS) and its surroundings have experienced record high surface temperatures (Mote, 2007, doi:10.1029/2007GL031976; Box et al., 2010), ice sheet melt extent (Fettweis et al., 2011, doi:10.5194/tc-5-359-2011) and record-low summer sea-ice extent (Nghiem et al., 2007, doi:10.1029/2007GL031138). Using three independent data sets, we derive, for the first time, consistent ice-mass trends and temporal variations within seven major drainage basins from gravity fields from the Gravity Recovery and Climate Experiment (GRACE; Tapley et al., 2004, doi:10.1029/2004GL019920), surface-ice velocities from Inteferometric Synthetic Aperture Radar (InSAR; Rignot and Kanagaratnam, 2006, doi:10.1126/science.1121381) together with output of the regional atmospheric climate modelling (RACMO2/ GR; Ettema et al., 2009, doi:10.1029/2009GL038110), and surface-elevation changes from the Ice, cloud and land elevation satellite (ICESat; Sorensen et al., 2011, doi:10.5194/tc-5-173-2011). We show that changing ice discharge (D), surface melting and subsequent run-off (M/R) and precipitation (P) all contribute, in a complex and regionally variable interplay, to the increasingly negative mass balance of the GrIS observed within the last decade. Interannual variability in P along the northwest and west coasts of the GrIS largely explains the apparent regional mass loss increase during 2002-2010, and obscures increasing M/R and D since the 1990s. In winter 2002/2003 and 2008/2009, accumulation anomalies in the east and southeast temporarily outweighed the losses by M/R and D that prevailed during 2003-2008, and after summer 2010. Overall, for all basins of the GrIS, the decadal variability of anomalies in P, M/R and D between 1958 and 2010 (w.r.t. 1961-1990) was significantly exceeded by the regional trends observed during the GRACE period (2002-2011). : Data extracted in the frame of a joint ICSTI/PANGAEA IPY effort, see http://doi.pangaea.de/10.1594/PANGAEA.150150