EcoAlert: Westerly Winds Found to Be Cause of Antarctic Ice Melt

1246588512147_1246588512147_r.gif Researchers have finally found an answer to a puzzle they have been pondering for years: Recent data and satellite information have indicated what has been driving the rapid loss of ice in Western Antarctica. The culprit is wind and underwater channels carved beneath the ice that allow warmer waters to seep in. Over the past decades, the westerly winds have become stronger, and as the wind moves faster, so does the water around the ice.

Glaciologists from the University of Colorado at Boulder and NASA's Goddard Space Flight Center have combined data from various sources to determine why Western Antarctica have been losing ice mass so rapidly, particularly the Antarctic Peninsula and Pine Island regions. Ice loss culprits include the loss off buttressing ice shelves, wind, and a sub-shelf channel that allows warm water to intrude below the ice.


"The westerly wind pattern drives everything in Antarctica," said Ted Scambos, a glaciologist at the National Snow and Ice Data Center in Boulder, Colo.

"Increased winds drag surface water faster, and this coupled with the Coriolis steers the water to the left and away from the continent, which leads to upwelling of warmer water into the area," said Bob Bindschadler, of NASA Goddard Center. The Coriolis effect, due to the Earth's rotation, causes air and fluid patterns  such as ocean currents  to deflect to the right in the Northern Hemisphere and deflect to the left in the Southern Hemisphere.

This warmer water in turn, contributes to the melting of the ice shelves, several of which have disintegrated in recent years, including the Larsen A and B ice shelves.

Airborne data showed the ice shelf was up to 492 feet (150 meters) thinner when the warmer water was present, allowing Bindschadler's team to establish a direct link between the rate of ice shelf melting and atmospheric wind speed. When the team accounted for the heat coming in and the ice lost, they concluded that only 22 percent of the heat is used in melting. Over the past decades, the westerlies have become stronger, and as the wind moves faster, so does the water around the ice.

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Jason McManus via ouramazingplanet.com

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