Super size Northern ozone hole of record sizeMonday, 10 October 2011
A hole in the ozone layer that was over Finland last spring has now been found to have been of record size, and comparable to the depletion of ozone over the Antarctic. Next spring, ozone levels over the country may fall again, raising the amount of UV radiation reaching the surface of the earth.
Last spring, more than a third of the ozone layer over Finland was depleted.
Leif Backman, a researcher at the Finnish Meteorological Institute, says that at an altitude of around 20 kilometers over the Arctic region, in the area of the North Pole, up to 80 percent of the ozone in the atmosphere has disappeared. These findings came out of detailed research only recently completed.
"It is the greatest loss of all time, the most so far that has been observed over the Arctic," Backman explains.
AdvertisementIn the wake of this historic depletion of ozone, researchers are no longer speaking of only a thinning of the layer, but of a hole like that long known to exist over the Antarctic.
"It has been a matter of dispute, but these conditions can now be compared to those over the Antarctic. To some extent we can now speak of an Arctic ozone hole as well," states Leif Backman.
The depletion of ozone is a late winter phenomenon, reversing after the winter has gone. However, the hole seen in the ozone layer last spring lingered over Finland longer than normal, all the way into April.
"If there is less ozone, UV levels are higher. For example, this past spring, the UV index was 3.5, which for the time of year is a high reading, but compared to normal summer levels it is not very significant. During the summer, the UV index in Finland can be somewhere between six and seven. If one is outdoors, it's worthwhile remembering, but it's not anything to worry about," says Backman.
In Finland, the late winter sun is so low in the sky that UV levels remain relatively low. However, reflection of sunrays from the snow increases the effect and can lead to sunburns even then.
News source: Yle - Finland