• DOI:10.1126/science.1228102
• Corpus ID: 32653236

A Reconciled Estimate of Ice-Sheet Mass Balance

@article{Shepherd2012ARE,
  title={A Reconciled Estimate of Ice-Sheet Mass Balance},
  author={Andrew Shepherd and Erik R. Ivins and Geruo A and Valentina R. Barletta and Michael J. Bentley and Srinivas V. Bettadpur and Kate H. Briggs and David H. Bromwich and Ren{\'e} Forsberg and Natalia Galin and Martin Horwath and Stanley S. Jacobs and Ian R. Joughin and Matt A. King and Jan T. M. Lenaerts and Jilu Li and Stefan R. M. Ligtenberg and Adrian John Luckman and Scott B. Luthcke and Malcolm McMillan and Rakia Meister and Glenn A. Milne and J{\'e}r{\'e}mie Mouginot and Alan S. Muir and Julien Nicolas and John D. Paden and Antony J. Payne and Hamish D. Pritchard and E. Rignot and Helmut Rott and Louise Sandberg S{\o}rensen and Theodore A. Scambos and Bernd Scheuchl and Ernst J. O. Schrama and Ben P Smith and Aud Venke Sundal and Jan H. Van Angelen and Willem Jan van de Berg and Michiel R. van den Broeke and David G. Vaughan and Isabella Velicogna and John M. Wahr and Pippa L. Whitehouse and Duncan J. Wingham and Donghui Yi and Duncan Alexander Young and H. Jay Zwally},
  journal={Science},
  year={2012},
  volume={338},
  pages={1183 - 1189}
}

• A. Shepherd, E. Ivins, +44 authors H. Zwally
• Published 30 November 2012
• Geology, Medicine
• Science

Warming and Melting Mass loss from the ice sheets of Greenland and Antarctica account for a large fraction of global sea-level rise. Part of this loss is because of the effects of warmer air temperatures, and another because of the rising ocean temperatures to which they are being exposed. Joughin et al. (p. 1172) review how ocean-ice interactions are impacting ice sheets and discuss the possible ways that exposure of floating ice shelves and grounded ice margins are subject to the influences of warming ocean currents. Estimates of the mass balance of the ice sheets of Greenland and Antarctica have differed greatly—in some cases, not even agreeing about whether there is a net loss or a net gain—making it more difficult to project accurately future sea-level change. Shepherd et al. (p. 1183) combined data sets produced by satellite altimetry, interferometry, and gravimetry to construct a more robust ice-sheet mass balance for the period between 1992 and 2011. All major regions of the two ice sheets appear to be losing mass, except for East Antarctica. All told, mass loss from the polar ice sheets is contributing about 0.6 millimeters per year (roughly 20% of the total) to the current rate of global sea-level rise. The mass balance of the polar ice sheets is estimated by combining the results of existing independent techniques. We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.