NASA model refines projections for Antarctica’s Thwaites Glacier

NASA reported new modelling of Antarctica’s Thwaites Glacier on 20 October. Researchers at NASA’s Jet Propulsion Laboratory, the University of California, Irvine and Dartmouth College focused on the area where ice leaves the seabed and begins to float. The underlying study appeared in Nature Communications on 12 October.

Rather than treating the transition as a single line, the model represents a grounding zone where seawater can move beneath ice and tides lift it. This can bring warmer water to grounded ice and affect its retreat. NASA says the model reproduced satellite-observed retreat since the 1990s four times more closely than models that omit the mechanism.

In some simulations, Thwaites’ contribution to sea-level rise by century’s end was as much as twice previous projections. That does not mean global sea level is certain to double: the statement concerns one glacier’s contribution under particular model assumptions.

Primary source: science.nasa.gov
Cover: Photo: NASA, image of the glacier from 2014.