Vast winter in my heart was released
Ozone could soon start to recover as the polar vortex breaks apart in the coming weeks.
With the Sun slowly getting higher, atmospheric temperatures in the region of the ozone hole have already started to increase, says Antje Inness, an atmospheric scientist with the European Centre for Medium-Range Weather Forecasts in Reading, UK.
“It wouldn’t be difficult to deal with,” Rex says. In the coming weeks, there is a small chance the hole might drift to lower latitudes over more populated areas - in which case people might need to apply sunscreen to avoid sunburn. The Arctic ozone hole isn’t a health threat because the Sun is just starting to rise above the horizon in high latitudes, says Rex. The Antarctic ozone hole is now on its way to recovery - last year’s hole was the smallest on record - but it will take decades for the chemicals to completely disappear from the atmosphere. Things would have been much worse this year if nations had not come together in 1987 to pass the Montreal Protocol, the international treaty that phases out the use of ozone-depleting chemicals, says Paul Newman, an atmospheric scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. She works with a NASA satellite instrument that measures chlorine in the atmosphere, and says there is still quite a bit of chlorine available to deplete ozone in the coming days. “We have at least as much loss as in 2011, and there are some indications that it might be more than 2011,” says Gloria Manney, an atmospheric scientist at NorthWest Research Associates in Socorro, New Mexico. The Arctic experienced ozone depletion in 1997 and in 2011 1, but this year’s loss looks on track to surpass those. “That beats any ozone loss we have seen in the past,” he notes. Where the balloons would normally measure around 3.5 parts per million of ozone, they recorded only around 0.3 parts per million, says Rex. By late March, these balloons measured a 90% drop in ozone at an altitude of 18 kilometres, which is right in the heart of the ozone layer. Researchers measure ozone levels by releasing weather balloons from observing stations around the Arctic (including the Polarstern icebreaker, which is frozen in sea ice for a year-long expedition). In the chilly temperatures, the high-altitude clouds formed, and the ozone-destroying reactions began. There was more cold air above the Arctic than in any winter recorded since 1979, says Markus Rex, an atmospheric scientist at the Alfred Wegener Institute in Potsdam, Germany. These conditions are much rarer in the Arctic, which has more variable temperatures and isn’t usually primed for ozone depletion, says Jens-Uwe Grooß, an atmospheric scientist at the Juelich Research Centre in Germany.īut this year, powerful westerly winds flowed around the North Pole and trapped cold air within a ‘polar vortex’. The Antarctic ozone hole forms every year because winter temperatures in the area routinely plummet, allowing the high-altitude clouds to form. Chemicals, including chlorine and bromine, which come from refrigerants and other industrial sources, trigger reactions on the surfaces of those clouds that chew away at the ozone layer. But each year in the Antarctic winter, frigid temperatures allow high-altitude clouds to coalesce above the South Pole. Ozone normally forms a protective blanket in the stratosphere, about 10 to 50 kilometres above the ground, where it shields life from solar ultraviolet radiation. Source: NASA Ozone Watch The hole’s formation