Scientists worldwide are worried the first time has been demonstrated over the Arctic, a true ozone hole. It had five times the size of Germany - and could occur more often in future.
Observed over the Antarctic in the southern hemisphere, researchers regularly for decades, an ozone hole. Now it has announced in the spring of 2011 for the first time over the North Pole region, a true ozone hole. The density of the protective ozone layer over the Arctic has fallen in 18 to 20 km altitude by more than 80 percent, says an international team of researchers in the journal "Nature".
Such a dramatic loss of ozone can have on the northern hemisphere have never seen before. Was the first time in the history of measurements of Arctic ozone loss to the ozone hole over Antarctica comparable, say, Gloria Manney of the California Institute of Technology in Pasadena and her colleagues
Ozone layer absorbs harmful ultraviolet radiation
The ozone layer is considered to be important protective shell of the earth, as it absorbs much of the harmful ultraviolet radiation from the sun. Decreases the density of ozone layer increases the risk of skin damage and skin cancer significantly. An ozone hole over the northern polar cap could mean as in the southern hemisphere in the northern hemisphere that is primarily for plant and animal hazards.
The focus of Arctic ozone hole in spring 2011 was indeed located on barely inhabited area, the researchers say. The hole of the five times the size of Germany was then pulled away in April but on Eastern Europe, Russia and Mongolia. Here, the ozone density had already recovered slightly. People were still high at times been exposed to radiation from ultraviolet light. Already in May, researchers have warned against the weak ozone layer over the Arctic and predicts danger for Germany.
Cold spell caused the ozone hole
Cause of the ozone hole in spring 2011, an unusually long cold period between December 2010 and March 2011 had been. She has given rise to a persistent cold air over the Arctic zone, the ozone-depleting reactions promoted. Until now, the Arctic have been considered too mild for such a cold air zones over such a long period and into the spring to allow inside.