In a study published today in the journal the Cryosphere, a team of researchers from the UK and Germany describe using a high-resolution, large-scale computer model to predict how climate change will affect the melting of the West Antarctic Ice Sheet (WAIS), and the rise of sea levels in the coming centuries. The researchers aimed to find out how the WAIS would respond to both moderate and extreme warming cases.
The video below depicts the creeping effects of climate change on glaciers of the Amundsen Sea Embayment—an ice sheet that drains into the Amundsen sea—over three centuries. The colours show the speed of ice flows in meters per year, with red areas representing 5,000 meters of ice flow per year, orange areas showing roughly 500 meters, and yellow areas representing around 50 meters of ice flow per year. The expanding bright blue area on the simulation reveals the grounding line—the boundary between the grounded ice and the floating ice shelf. Rapid decline of the WAIS increases sea levels, leading to greater risks of floods and rockslides.
"We subjected an ice dynamics model to a range of ocean and atmospheric changes, ranging from no change at all, through the future changes projected by state-of-the-art ocean and atmosphere models, to extreme changes intended to study the upper reaches of future sea-level rise," said Stephen Cornford, study lead-author and a research associate at the University of Bristol, UK, in a press statement.
According to the researchers, no models have previously existed to quantify the melting of ice sheets and the subsequent effect on the rise of sea levels with such precision.
"Much like a higher-resolution digital camera transforms a blur into a flock of birds, higher resolution in a computer model often helps to capture details of the physics involved which may be crucial to the broad picture," said study co-author, Dan Martin from the Lawrence Berkeley National Laboratory in California, US, in a press release.
West Antarctica has been rapidly losing its ice sheet over recent years, with the Pine Island Glacier depositing an iceberg the size of Manhattan into the sea in 2013. In their study, the researchers state the the snowfall currently received by the West Antarctic Ice Sheet (WAIS) is not enough to make up for the mass that it loses into the oceans on a yearly basis.
"We expect future change in the West Antarctic Ice Sheet to be dominated by thinning in the Amundsen Sea Embayment, just as it is today, until at least the 22nd century," said Cornford. "But other regions of West Antarctica could thin to a similar extent if the ocean warms sufficiently."