Archive

Posts Tagged ‘ozone layer’

Ozone layer damaged by unusually harsh winter

April 6, 2011 1 comment

independent

An image of total ozone column profile around the North Pole on March 30, 2011, developed by the Finnish Meteorological Institute using satellite and ground-based data, is seen in this handout, April 5, 2011. Satellite measurement of total ozone from OMI (Ozone Monitoring Instrument) shows a region of low ozone (blue region) above the Arctic regions. As of late March the ozone-poor region is shifted away from the pole and covers Greenland and Scandinavia. — WMO via Reuters

The stratospheric ozone layer, which shields the Earth from the Sun’s harmful ultraviolet rays, has been damaged to its greatest-ever extent over the Arctic this winter.

The protective layer of gas, which can be destroyed by reactions with industrial chemicals, has suffered a loss of about 40 per cent from the start of winter until late March, exceeding the previous seasonal loss of about 30 per cent, according to the World Meteorological Organisation (WMO).

The phenomenon is annual in the Antarctic, where after its discovery in the 1980s it came to be known as the “ozone hole“. Although CFC levels are now dropping, they remain in the atmosphere for so long that they will still be causing ozone depletion for decades in certain conditions, particularly the intense cold of the stratosphere.

Arctic ozone conditions vary more and the temperatures are always warmer than over Antarctica, where the ozone hole forms high in the stratosphere near the South Pole each winter and spring. Because of changing weather and temperatures, some Arctic winters experience almost no ozone loss – but others with exceptionally cold stratospheric conditions can occasionally lead to substantial ozone depletion.

This is what has happened over the Arctic this winter; for while at ground level the Arctic region was unusually warm, temperatures 15-20km above the Earth’s surface plummeted. WMO officials say the latest losses, which are unprecedented, were detected in Read more…