TORONTO – At a time when scientists are calling into question the issue of global warming, new research has found an explanation for the puzzling growth of Antarctic sea ice.
Though the air and oceans have warmed, there’s more sea ice in Antarctica now than there was in the 1970s, something that has long puzzled scientists and also bolstered global warming skeptics.
“The overwhelming evidence is that the Southern Ocean is warming,” said author Jinlun Zhang, an oceanographer at the University of Washington Applied Physics Laboratory. “Why would sea ice be increasing? Although the rate of increase is small, it is a puzzle to scientists.”
Zhang’s study, which used a computer model, found that stronger westerly winds that circle around the South Pole explain about 80 percent of the increase in Antarctic sea ice over the past 30 years.
Not only is the polar vortex stronger than it was when records began in the 1970s, but it also has something called convergence, which causes sea ice to be shoved together. The winds drive the ice faster which leads to ridging, which in turn leads to thicker, longer-lasting ice.
It is unknown why the winds in the south are getting stronger.
The Antarctic has seen an increase in sea ice, but the sea ice in the Arctic has decreased. Though the Arctic ice has seen an increase in 2013, in 2012 the ice melt reached record proportions.
Zhang believes that if the warmer global temperatures continue, the Antarctic trend will reverse.
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