A NASA map shows the size of the Antarctic ozone hole at its largest point this year, when it spread to the size of North America.
The ozone layer protects life on Earth from the sun's ultraviolet rays. Where the ozone layer is thinner, there is more danger from UV rays, which put humans at risk of skin cancer, sunburns and cataracts.
The map, posted by the NASA Earth Observatory, reveals that the hole, which lies above the South Pole, was 10 million square miles on September 21, making it the 12th largest single-day ozone hole since 1979, the observatory said.
Moderate ozone losses are shown in orange and more potent areas of loss in red. While the hole may look large, it does mark an improvement, compared with previous years.
"It's a very modest ozone hole," Paul Newman, leader of NASA's ozone research team and chief scientist for Earth sciences at NASA's Goddard Space Flight Center, said in a press release. "Declining levels of human-produced chlorine compounds, along with help from active Antarctic stratospheric weather, slightly improved ozone levels this year."
Every September, the ozone layer over Antarctica thins. The layer does not completely disappear, but its concentrations drop below a certain threshold.
Scientists have been keeping tabs on the thinning of the ozone layer every year since 1985, when they first discovered its depletion.
This depletion occurs when chemicals containing bromine and chlorine rise into the stratosphere. Human activities have created an abundance of these chemicals, which destroy ozone molecules, effectively punching a hole in the layer. These chemicals can be found in such things as spray cans and refrigerants.
There is such a high concentration of chlorine and ozone-depleting chemicals in the stratosphere that scientists have predicted levels will not return to pre-1980 levels until the middle decades of the 21st century. Models have shown that these chemicals will continue to affect the ozone layer until the middle of the 21st century.
The good news is that the ozone layer is recovering. In the winter months of 2005 and 2016, scientists saw a 20 percent decrease in ozone thinning—the first evidence that it was recovering. So far, they estimate that this ozone hole will recover by 2040.
Weather events can also affect the ozone layer and the amount of depletion. Abnormal weather patterns in Antarctica in 2019 led to the smallest hole since 1982.
Other factors have affected the ozone layer besides human activities.
Scientists recently found that the 2022 eruption of the Hunga Tonga-Hunga Ha'apai volcano tore a chunk out of the Earth's ozone layer as a result of huge volumes of water vapor that poured into the stratosphere. A study reported that the ozone layer was depleted by up to 5 percent.
Do you have a tip on a science story that Newsweek should be covering? Do you have a question about the ozone layer? Let us know via science@newsweek.com.
About the writer
Robyn White is a Newsweek Nature Reporter based in London, UK. Her focus is reporting on wildlife, science and the ... Read more
To read how Newsweek uses AI as a newsroom tool, Click here.
