Mass balance of the Greenland ice sheet from 1958 to 2007

We combine estimates of the surface mass balance, SMB, of the Greenland ice sheet for years 1958 to 2007 with measurements of the temporal variability in ice discharge, D, to deduce the total ice sheet mass balance. During that time period, we find a robust correlation (R2 = 0.83) between anomalies in SMB and in D, which we use to reconstruct a continuous series of total ice sheet mass balance. We find that the ice sheet was losing 110 +/- 70 Gt/yr in the 1960s, 30 +/- 50 Gt/yr or near balance in the 1970s-1980s, and 97 +/- 47 Gt/yr in 1996 increasing rapidly to 267 +/- 38 Gt/yr in 2007. Multi-year variations in ice discharge, themselves related to variations in SMB, cause 60 +/- 20\% more variation in total mass balance than SMB, and therefore dominate the ice sheet mass budget.