December 24, 2012
Rapid Warming At West Antarctic Ice Sheet Could Contribute To Sea Level Rise
redOrbit Staff & Wire Reports - Your Universe Online
A portion of the Antarctic ice sheet is warming nearly twice as quickly as experts had previously believed, which could increase the region's future contribution to rising sea levels, a team of researchers from the Ohio State University (OSU) has discovered.According to BBC News Environmental Correspondent Matt McGrath, the study authors analyzed temperature records from Byrd Station, a scientific outpost in the center of the West Antarctic Ice Sheet (WAIS), and discovered the area had increased 4.3 degrees Fahrenheit (2.4 degrees Celsius) in average annual temperature from 1958 to 2010.
This marks the first time scientists have managed to use the Byrd Station records to draw climate-related conclusions, as the data from the station was incomplete. McGrath explains the OSU researchers were able to fill in the blanks using a computer model of the Earth's atmosphere and numerical analysis methods.
"Our record suggests that continued summer warming in West Antarctica could upset the surface mass balance of the ice sheet, so that the region could make an even bigger contribution to sea level rise than it already does," David Bromwich, a geography professor at the university as well as a senior research scientist at the Byrd Polar Research Center, said in a statement.
"Even without generating significant mass loss directly, surface melting on the WAIS could contribute to sea level indirectly, by weakening the West Antarctic ice shelves that restrain the region's natural ice flow into the ocean," he added. "West Antarctica is one of the most rapidly changing regions on Earth, but it is also one of the least known. Our study underscores the need for a reliable network of meteorological observations throughout West Antarctica, so that we can know what is happening -- and why -- with more certainty."
Bromwich and his colleagues, whose findings have been published online in the journal Nature Geoscience, say the WAIS is particularly sensitive to the effects of global warming, since its base is below sea level. Due to that fact, it is susceptible to warmer ocean water, and it is currently responsible for adding 0.3mm to the rising sea levels each year, second only to Greenland.
Co-author Dr. Andre Monaghan, a scientist at the US National Center for Atmospheric Research (NCAR), told McGrath, "What we're seeing is one of the strongest warming signals on Earth. This is the first time we've been able to determine that there's warming going on during the summer season.
"We're seeing a more dynamic impact that's due to climate change that's occurring elsewhere on the globe translating down and increasing the heat transportation to the WAIS," he continued, adding he was not 100-percent certain human activities played a role in the higher warming levels. "The jury is still out on that. That piece of research has not been done. My opinion is that it probably is, but I can't say that definitively."