The ozone layer over Antarctica feels great, and the rent may take ten years earlier than scientists expected.
The ozone hole was first discovered in 1985, was soon associated with chlorofluorocarbons (CFCs), which are produced mainly in the Northern Hemisphere, but as a result of atmospheric flows are concentrated over the South Pole. The chlorine atoms react with ozone molecules and destroy the layer that protects the planet from harmful ultraviolet radiation.
|The ozone hole in September 2006 (NASA image).|
In 1989, suffering planet took over as the Montreal Protocol — an international instrument banning CFCs. Then experts thought that the first signs of recovery can be observed only in our day, but new research suggests that improvements began in the late nineties. "Then the annual fluctuations have hidden from us long-term evolution of ozone," — said the study's author Merry Solbi from Macquarie University (Australia).
Indeed, the concentration of ozone changes dramatically from year to year because of the complex atmospheric processes, and therefore to understand what was going on, it is very difficult. Scientists decided to concentrate on the impact that the winter dynamic factors on how much ozone is destroyed during the following spring. In other words, winter atmospheric processes determine how many atoms of chlorine leaves CFC molecules. A direct connection between the winter and spring atmosphere ozone depletion, the researchers found that in 1979, ozone levels declined sharply, and after 1996, began to slow growth.
Other scientists could show only slow down the destruction of the ozone layer, and a new work, many seemed unconvincing. "I think that the Antarctic ozone is indeed recovering, but we need more statistics to prove it," — says Darrin Waugh at Johns Hopkins University (USA). "You should be careful — agrees Paul Young of the National Oceanic and Atmospheric Administration (USA). — It's too bold statement. "
Experts agree on one thing: whatever happened to the ozone hole, she was destined to live long. No one is waiting until her disappearance in 2070.
Note that the ozone layer over the Arctic is also a problem: he is now thinned as ever.
The study is published in the journal Geophysical Research Letters.
Prepared according ScienceNews.