Arctic storms decrease
Brief but vicious Arctic storms known as polar lows are likely to
become much less frequent as global warming intensifies, scientists in
Britain determined on Wednesday.
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Arctic storm. AFP |
Polar lows brew in ice-free high latitudes in the North Atlantic in
winter and can swiftly become a hazard for shipping and oil rigs.
The number of these storms averaged 36 per season in the 20th
century, climatologists at the University of Reading said.
By 2100, this tally would fall to between 17 and 23 per season,
depending on concentrations of heat-trapping greenhouse gases in the
air.
“There would be roughly only half as many in future,” Matthias Zahn,
of the university’s Environmental Systems Science Centre, told AFP.
The simulation is based on three scenarios for greenhouse-gas
emissions used by the UN’s Intergovernmental Panel on Climate Change (IPCC).
The reason for the fall lies in a change in the difference in
temperature between the ocean’s surface and the mid-atmosphere.
This differential is what causes a polar low to develop. Changing the
difference hampers the storm’s formation and intensification, according
to the paper, released by Nature, the British science journal. Zahn said
further work was underway to simulate polar lows in the northern
Pacific.
AFP
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