Thursday, December 17, 2020

A study by UNCW researchers Mark England and Till Wagner, funded by the National Science Foundation, lays the groundwork for incorporating the impact of Antarctic icebergs into global climate models. Their findings were published Dec. 16 in the cover article of the journal Science Advances.
 
The project was led by England, a postdoctoral research fellow at UNCW and the Scripps Institution of Oceanography at the University of California San Diego. Ian Eisenman, an associate professor with Scripps Oceanography, was also part of the research team.
 
Building on a model previously developed by Wagner, UNCW assistant professor of physics and physical oceanography, England and the team created a model to predict how often the icebergs would break up and where they would drift. These icebergs have not typically been included in global climate models because they were difficult to simulate.
 
“We know that large tabular icebergs deliver about half of the freshwater from the Antarctic ice sheets to the Southern Ocean, and their importance in the climate system will likely increase over the coming century,” said England. “We think this an important step forward toward including these giant icebergs in global climate models and being able to incorporate their effects into climate change projections.”
 
Antarctic icebergs are generally tabular, or flat on top, with steep sides. As they break up and melt, the fresh water they add to the ocean affects salinity and the currents that are important in regulating global climate.
 
These icebergs can be massive. “The largest one we replicated is almost the size of New York City,” said Wagner. “An iceberg that large has the potential to put 300 billion tons of fresh water into the Southern Ocean – that’s enough to supply the entire U.S. consumption for about 10 days.”
 
The researchers stress that these larger icebergs, which can be expected to dramatically increase in number in the future, need to be taken into consideration when developing climate models to avoid inaccurate results.
 
“Our results show that giant icebergs spread Antarctic freshwater much further from the coast than previous studies have assumed,” Wagner said. “This may have important consequences for the dynamics of the Southern Ocean.”
 
Research and collaboration are among the key components of UNCW’s Strategic Plan.
 
“The work by Dr. Wagner and colleagues represents a significant advance in our understanding of the Earth system,” said Stuart Borrett, associate provost for research and innovation at UNCW. “Their work substantially improves the models of ice flow and freshwater dynamics in the Southern Ocean. This understanding is essential to improving our understanding of climate science and our ability to predict the impact of our changing climate. It’s exciting to see this truly global impact of UNCW research and innovation.”
 
-- Tricia Vance

Antarctic tabular icebergs float in the Southern Ocean. The icebergs can be the size of cities or even small U.S. states. (Photo by Chris Packham)

A series of Antarctic icebergs, photographed at a distance. (Photo by Chris Packham)

 
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