Recently, a huge hole in the ozone layer has appeared over the Arctic, which is probably the largest hole ever seen in the region, about the size of the ozone hole that forms in Antarctica every year. Ozone levels in much of the central Arctic, which covers about three times the size of Greenland, are at record lows, and the hole in the ozone layer, which is likely to rupture in the coming weeks, will not pose a threat to human health, but it will go down in history as an extraordinary atmospheric phenomenon, Nature reported.
A rare hole in the ozone layer has appeared over the Arctic. Photo credit: NASA Ozone Watch
“In my opinion, this is the first time a real Hole in the Arctic ozone layer has been found. Martin Dameris, an atmospheric scientist at the German Aerospace Center, said. Ozone usually forms a protective layer in the stratosphere, about 10 to 50 kilometers above the ground, protecting life from solar ultraviolet radiation. Every winter, cold weather causes high-altitude clouds to gather over the South Pole. Chemical substances, including chlorine and bromine from refrigerants and other industrial sources, trigger reactions on the surface of clouds and erode the ozone layer.
The Antarctic ozone hole forms every year because temperatures in the region usually drop sharply during the winter months, creating high-altitude clouds. “These conditions are rare in the Arctic, where temperature changes are larger and usually do not cause ozone depletion. Jens-Uwe Groo, an atmospheric scientist at the Ulrich Research Center in Germany, said.
But this year’s strong westerly winds are circling the Arctic, trapping cold air in a “polar vortex.” Markus Rex, an atmospheric scientist at the Alfred Wegner Institute in Germany, says the cold air over the Arctic is stronger than in any winter since 1979. In cold temperatures, high-altitude clouds form and the reaction to the destruction of the ozone layer begins.
The researchers measured ozone levels by releasing weather balloons from observatories near the North Pole. By the end of March, the balloons had measured ozone levels in the ozone layer core region at an altitude of 18 kilometres by 90 per cent. Weather balloons typically measure ozone levels of about 3.5 ppm, but they record only 0.3 ppm, Rex said. “This is more severe than any ozone loss we’ve seen in the past. He said.
The Arctic experienced ozone depletion in 1997 and 2011, but this year’s loss may have exceeded that of the past. “This year’s ozone depletion is at least as much as it was in 2011, and there are signs that more is likely to be done. Gloria Manney, an atmospheric scientist at the Northwest Research Association, says there will still be a significant amount of chlorine in the coming days.
Paul Newman, an atmospheric scientist at NASA’s Goddard Space Flight Center, said the situation could have been worse this year if countries had not jointly adopted the Montreal Protocol in 1987. Although the Antarctic ozone hole is now recovering, and last year’s hole was the smallest on record, it will be decades before the chemicals completely disappear from the atmosphere.
“The Arctic ozone hole does not pose a health threat, as the sun at high latitudes is only just beginning to rise from the horizon. Rex said. Over the next few weeks, the hole has little chance of drifting into densely populated low-latitude areas – in which case people may need to apply sunscreen to avoid sunburn. The next few weeks are crucial. Antje Innes, atmospheric scientist at the European Centre for Medium-Term Weather Forecasting, says the sun is slowly rising and atmospheric temperatures in the ozone hole region are starting to rise. Ozone levels may soon begin to recover as the polar vortex ruptures in the coming weeks.