Unlike the Arctic, where much of the sea ice is — at least for now — year-round, the Southern Ocean’s sea ice is thin and seasonal. And during the latter half of the 20th century, its winter surface area has increased.
Indeed, global warming appears to have been protective. By combining temperature and precipitation records with simulations of Southern Ocean climate, Curry and Liu linked the 20th-century warming of .36 degrees Fahrenheit in the Southern Ocean’s upper waters to increased regional snowfall. The finding makes intuitive sense: Rising temperatures increase the amount of moisture in the air, which eventually becomes snow. And for the last few decades, that snow kept surface waters from warming even more, added bulk to sea ice, and reflected sunlight.
But as the Antarctic continues to warm, Curry and Liu’s models show snow becoming rain (see image below), even as total precipitation rises (see image above). By the century’s end, they predict snowfall retreating to the Antarctic continent’s edge. The Southern Ocean at large will be rainy. Sea ice will contract. Continental ice will continue to melt.
Read More http://www.wired.com/wiredscience/2010/08/antarctic-ice-future/#ixzz0zW2AncOb
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