A huge ozone hole opened this year over the Arctic. While ozone holes usually form in the Antarctic zone every year, because winter temperatures fall to extremely low values, allowing high-altitude clouds to develop – the Arctic has more variable temperatures and usually does not reach the point of destroying the ozone layer.
Although the hole is not a health hazard right now, as the sun is just beginning to rise above the horizon at high latitudes, there is little chance that the hole can move to lower latitudes and more populated areas.
This zone of low ozone levels encompasses the central part of the region — an area that is about three times the size of Greenland. The destruction of the ozone layer in the Arctic was recorded only twice – in 1997 and 2011.
“There are some signs that this could be worse than in 2011,” said Gloria Manny, an atmospheric scientist.
Martin Daeris, another atmospheric scientist from the German Aerospace Center, noted that this is the first time that experts can discuss a real ozone hole in the Arctic.
According to Jens-Uwe Gruss, an atmospheric scientist from the Jülich Research Center in Germany, the Arctic has more variable temperatures and usually does not reach the destruction of the ozone layer, so ozone holes are rarely found in this area.
However, this year powerful westerly winds flowed around the North Pole, holding the cold air inside the polar vortex. With these extremely cold temperatures, alpine clouds formed, triggering a reaction that destroyed ozone.
By the end of March, there was a 90 percent drop in ozone at an altitude of 18 km, from the usual 3.5 ppm of ozone to 0.3. “This is more than any ozone loss we have seen in the past,” said atmospheric scientist Marcus Rex of the Alfred Wegener Institute.
Professionals believe that the coming weeks will be critical. At the moment, the Arctic ozone hole does not pose a threat to health, since the sun is just beginning to rise above the horizon in high latitude areas.
Antje Inness, an atmospheric scientist at the European Center for Medium-Range Weather Forecasts, said the temperature in the region has begun to rise, so ozone should begin to recover as the polar vortex breaks apart in the next few weeks.
However, there is little chance that the hole could move to lower latitudes and more populated areas. If so, people will need to use sunscreen outdoors.
“Right now, we are watching with alarm what is happening,” said atmospheric scientist Ross Salavich of the University of Maryland. “The game is not over yet.”