Super size Northern ozone hole of record size
Monday, 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
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
"It is the greatest loss of all time, the most so far that has been observed over the Arctic," Backman explains.
In 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.
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