A new study funded by the National Science Foundation (NSF) finds that the western part of the massive West Antarctic Ice Sheet (WAIS) is experiencing nearly twice as much warming as previously thought.
The findings were published online this week in the journal Nature Geoscience. NSF manages the U.S. Antarctic Program (USAP) and coordinates all U.S. research and associated logistics on the southernmost continent and in the surrounding Southern Ocean.
The temperature record from Byrd Station, an unmanned scientific outpost in the center of the ice sheet, demonstrates a marked increase of 4.3 degrees Fahrenheit (2.4 degrees Celsius) in average annual temperature since 1958. That is three times faster than the average temperature rise around the globe.
This temperature increase is nearly double what previous research has suggested, and reveals--for the first time--warming trends during the summer months of the Southern Hemisphere (December through February), said David Bromwich, professor of geography at Ohio State University and senior research scientist at the Byrd Polar Research Center.
"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," said Bromwich.
"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."
Andrew Monaghan, study co-author and scientist at the National Center for Atmospheric Research (NCAR), said that these findings place West Antarctica among the fastest-warming regions on Earth.
"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," Monaghan said. "The stakes would be much higher if a similar event occurred to an ice shelf restraining one of the enormous WAIS glaciers."
Researchers consider the WAIS especially sensitive to climate change, explained Ohio State University doctoral student Julien Nicolas. Since the base of the ice sheet rests below sea level, it is vulnerable to direct contact with warm ocean water. Its melting currently contributes 0.3 mm to sea level rise each year--second to Greenland, whose contribution to sea-level rise has been estimated as high as 0.7 mm per year.
Due to its location some 700 miles from the South Pole and near the center of the WAIS, Byrd Station is an important indicator of climate change throughout the region.
In the past, researchers haven't been able to make much use of the Byrd Station measurements, due to the fact that since the station was establishment in 1957, it hasn't always been occupied. So, its data were incomplete, to the point that nearly one third of the temperature observations were missing for the time period of the study. A year-round automated station was installed in 1980, but it has experienced frequent power outages, especially during the long polar night, when its solar panels can't recharge.
Bromwich and two of his graduate students, along with colleagues from the National Center for Atmospheric Research and the University of Wisconsin-Madison, corrected the past Byrd temperature measurements and used corrected data from a computer atmospheric model and a numerical analysis method to fill in the missing observations.
Aside from offering a more complete picture of warming in West Antarctica, the study suggests that if this warming trend continues, melting will become more extensive in the region in the future, Bromwich said.
While the researchers work to fully understand the cause of the summer warming at Byrd Station, the next step is clear, he added.
"West Antarctica is one of the most rapidly changing regions on Earth, but it is also one of the least known," he said. "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."
National Science Foundation: http://www.nsf.gov
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Researchers had tried for 23 years to connect this piece of metal to Amelia Earhart's disappearance. They finally think they've proven it was part of her plane.
Michelangelo painted the ceiling of the Sistine Chapel by the light of the sun coming through small windows, and now 450 years after his death, his masterpieces are being seen in a whole new light provided by 7,000 LEDs. The chapel is also getting a new ventilation system. Allen Pizzey reports.
Reports that a passenger photographed a rainbow from her plane are mistaken. The colours are caused by polarisation
Jiri Bruthans created this pillar with simulated salt weathering; in nature (like at Bryce Canyon, below), factors like frost and rain also shape the landscape. Courtesy of Jiri Bruthans Getty Aa the story goes, the iconic spires in Utah's Bryce Canyon National Park once were human-animal “legend people,” until an angry coyote god turned them […]
The discovery of a third type of light associated with dark matter could strengthen the case that we are seeing a signal of the mysterious stuff
The flow, which began at Mount Kilauea in June, threatens to take out dozens of homes on the Big Island.
Written 20 years ago, the first algorithm to tap into the ultra-fast potential of quantum computing has been run on a real machine at long last
Shirley Corriher, author of Cookwise: The Hows and Whys of Successful Cooking, has tips on taking the bitter bite out of coffee, and holding onto cabbage's red hue while it's in the pan.
Data originally taken for another reason weaken the case for "dark photons"
Kip Thorne looks into the black hole he helped create and thinks, “Why, of course. That's what it would do.” This particular black hole is a simulation of unprecedented accuracy. It appears to spin at nearly the speed of light, dragging bits of the universe along with it. (That's gravity for you; relativity is superweird.) In theory it was once a star, but instead of fading or exploding, it collapsed like a failed soufflé into a tiny point of inescapable singularity. A glowing ring orbiting the spheroidal maelstrom seems to curve over the top and below the bottom simultaneously.