Different magnitudes of projected suburface ocean warming around Greenland and Antarctica

• Published in: Nature Geoscience
• Other Authors: Yin, Jianjun (author), Overpeck, Jonathan (author), Griffies, Stephen (author), Hu, Aixue (author), Russell, Joellen (author), Stouffer, Ronald (author)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2011
• Subjects: Greenland; Antarc*; Antarctica; Ice Sheet
• Online Access: http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-848; https://doi.org/10.1038/NGEO1189

The observed acceleration of outlet glaciers and ice flows in Greenland and Antarctica is closely linked to ocean warming, especially in the subsurface layer. Accurate projections of ice-sheet dynamics and global sea-level rise therefore require information of future ocean warming in the vicinity of the large ice sheets. Here we use a set of 19 state-of-the-art climate models to quantify this ocean warming in the next two centuries. We find that in response to a mid-range increase in atmospheric greenhouse-gas concentrations, the subsurface oceans surrounding the two polar ice sheets at depths of 200 - 500m warm substantially compared with the observed changes thus far. Model projections suggest that over the course of the twenty-first century, the maximum ocean warming around Greenland will be almost double the global mean, with a magnitude of 1.7 - 2.0°C. By contrast, ocean warming around Antarctica will be only about half as large as global mean warming, with a magnitude of 0.5 - 0.6°C. A more detailed evaluation indicates that ocean warming is controlled by different mechanisms around Greenland and Antarctica. We conclude that projected subsurface ocean warming could drive significant increases in ice-mass loss, and heighten the risk of future large sea-level rise.