Western Antarctica experiences rapid warming
The western part of Antarctica is warming three times faster than the average global temperature increase.
Average summer temperature recordings from the Byrd Station on the Western Antarctic Ice Sheet (WAIS) have increased by 4.3 degrees Fahrenheit (2.4 degrees Celsius) since 1958. The finding raises concerns about Antarctic ice melt contributing to increasing sea levels.
"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," says David Bromwich, senior research scientist at the Byrd Polar Research Centre.
"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."
The study, published in Nature Geoscience, reveals for the first time warming trends in Antarctica over the summer months. The temperature increase is greater than previous studies have found and place Antarctica as one of the fastest warming regions on the planet.
"We've already seen enhanced surface melting contribute to the breakup of the Antarctic's Larsen B Ice Shelf, where glaciers at the edge discharged massive sections of ice into the ocean that contributed to sea level rise," says Andrew Monaghan, a research scientist at the National Centre for Atmospheric Research (NCAR).
"The stakes would be much higher if a similar event occurred to an ice shelf restraining one of the enormous WAIS glaciers."
The team believe that the WAIS is particularly vulnerable to climate change as the bottom part of the ice sheet rests below sea level, bringing it into direct contact with warm ocean water. Currently Antarctica contributes 0.3mm per year to increasing sea levels, second only to Greenland at 0.7mm per year.
The scientists are still trying to understand the exact causes of the rising temperatures on the WAIS but believe that our understanding would benefit from increasing the number of observation stations on the WAIS.
"West Antarctica is one of the most rapidly changing regions on Earth, but it is also one of the least known," says Bromwich.
"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."