West Antarctic coastal snow accumulation rose 30 percent during 20th century
- November 4, 2015
- American Geophysical Union
- Annual snow accumulation on West Antarctica’s coastal ice sheet increased dramatically during the 20th century, according to a new study. The research gives scientists new insight into Antarctica’s blanket of ice. Understanding how the ice sheet grows and shrinks over time enhances scientists’ understanding of the processes that impact global sea levels.
Annual snow accumulation on West Antarctica’s coastal ice sheet increased dramatically during the 20th century, according to a new study published in the American Geophysical Union journal Geophysical Research Letters.
The research gives scientists new insight into Antarctica’s blanket of ice. Understanding how the ice sheet grows and shrinks over time enhances scientists’ understanding of the processes that impact global sea levels, according to the study’s authors.
The new study used ice cores to estimate annual snow accumulation from 1712 to 2010 along West Antarctica’s coast. Until 1899, annual snow accumulation remained steady, averaging 33 and 40 centimeters (13 and 16 inches) of water, or melted snow, each year at two locations.
Annual snow accumulation increased in the early 20th century, rising 30 percent between 1900 and 2010, according to the new study. The study’s authors found that in the last 30 years of the study, the ice sheet gained nearly 5 meters (16 feet) more water than it did during the first 30 years of the studied time period.
“Since the record is 300 years long, we can see that the amount of snow that has been accumulating in this region since the 1990s is the highest we have seen in the last 300 years. The 20th century increases look unusual,” said Elizabeth Thomas, a paleoclimatologist with the British Antarctic Survey in Cambridge, United Kingdom, and lead author of the new study.
Thomas attributes the higher annual snow accumulation over the last 30 years in part to an intensification of a regional low pressure system and more storms in the region. The study’s authors said these storms could increase with climate change, possibly leading to further increases in snow accumulation.
Snow accumulation builds up the ice sheet, but the extra flakes have not acted as a life raft for West Antarctica’s ice sheet, which previous research has found is rapidly thinning as the climate warms, Thomas said.
The size of the ice sheet depends on how much new snow accumulates and how much of the existing ice melts, she said. Knowledge about how much new snow is laid down in West Antarctica each year could help scientists more accurately predict how the region’s coastal ice sheet could be affected by climate change and its contribution to sea level rise, Thomas said.