September 16, 2010

Global Warming Could Affect Arctic Storms

Climate changes brought on by global warming could lead to less frequent Arctic storms known as polar lows, British scientists said Wednesday.

Polar lows form in ice-free high latitudes in the North Atlantic during the winter and can cause havoc on ships and oil rigs.

There was an average 36 storms per season during the 20th century, according to climatologists at the University of Reading.

That number could fall to between 17 and 23 per season, depending on concentrations of heat-trapping greenhouse gases in the atmosphere.

Matthias Zahn, of the Environmental Systems Science Center at Reading, told AFP "There would be roughly only half as many [polar lows] in future."

The reason for the decline lies in a change in the difference in temperature between the ocean surface and the mid-atmosphere. This differential is what causes a polar low to develop. Altering the difference hinders the storm's formation, according to the paper, released by the British science journal Nature.

The UN's Intergovernmental Panel on Climate Change has three scenarios that are used to simulate greenhouse-gas emissions.

Zahn said further work was underway to simulate polar lows in the northern Pacific.


Image Caption: Polar low over the Barents Sea on February 27, 1987. Credit: NOAA


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