Wednesday, November 05, 2014

Shifting Winds Warming Antarctica

Foreboding winds of change are blowing over the already gale-swept South Pole, threatening to hasten Antarctic melting and worsen flooding around the globe.

The Southern Ocean’s legendary winds have been blowing more fiercely and in a more poleward direction since the 1950s. Temperature observations are sparse around the hostile continent, but scientists recently modeled the ocean current knock-on effects of these wind changes, which have been caused by ozone thinning and by the buildup of greenhouse gases.

The scientists were blown away by the vicious climate change feedback that they unearthed.

The researchers reported that the shifting winds “produce an intense warming” just below the surface of the ocean. The wind changes were found to be heaving warm currents from deeper waters up into a zone where the Antarctic ice sheet is vulnerable to melt and crumble from beneath — the area where towers of ice sit atop submerged ground.

“It’s a very simple mechanism that we’re identifying,” said Stephen Griffies, a National Oceanic and Atmospheric Administration scientist who contributed to the modeling research, which was published in Geophysical Research Letters. “You raise the warm water to the depth of the ice shelves through the wind changes.”

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