Antarctic winds likely to accelerate sea level rise, researchers say

SYDNEY, July 7 (UPI) -- Australian researchers say computer models predicting the rate of polar ice melting and sea level rise are too conservative and have failed to account for increasingly disruptive westerly winds in the Antarctic.

Paul Spence, an oceanographer at the University of New South Whales' Climate Change Research Center, says westerly winds in the Southern Ocean will soon conflate the coastal easterlies and confuse the balance of cold and warm water just off the Antarctic shore.

Currently, a band of frigid water encircles Antarctica, protecting its icy shore and the ice sheets beyond. But just beyond this insulant is another band of water, this one four degrees warmer. Spence and his colleagues say changing wind patterns -- at least partially fueled by global warming -- are beginning to push more and more warm water in, and more and more cold water out.

Recent studies have already predicted that the ice sheets of West Antarctica have already become so unstable that their eventual melting is irreversible -- raising sea levels a few feet over the next several hundred years.

But in his latest paper -- published recently in the journal Geophysical Research Letters -- Pence says these predictions could look like wishful thinking if new wind patterns hold true.

"They weren't considering the types of temperature -- of warming that we're seeing in our model simulations around coastal Antarctica," Spence told the Australian Broadcasting Corporation in a recent interview. "Not just the West Antarctic Ice Sheet, but we also get significant warming of up to four degrees Celsius in regions of the East Antarctic Ice Sheet as well.

"If you look at how sensitive the coastal ocean is to these changing winds, you could put a lot more heat under these ice shelves than people have previously thought," Spence told The Sydney Morning Herald.

Spence says when accounting for the newly disruptive westerly winds, models show more drastic sea level rise could arrive this century, as opposed to two or three hundred years from now, as previously suggested.

"It's not unlike an avalanche of snow where you don't quite know when it's going to happen," he said. "But when it happens, it can happen quickly.