Earlier this month, TheBlaze reported that statistics from the National Snow and Ice Data Center showed a record high in Antarctic sea ice levels. Scientists were attributing this to global warming that lead to the ozone hole above the southern-most continent to contribute to cooler weather, which promoted these ice levels.
Almost a month later, NASA released a report saying the Antarctic ozone hole is now the second smallest it has been in 20 years, thanks to cooler temperatures higher in the atmosphere.
Antarctic ozone hole on Sept. 22. (Image: YouTube screenshot)
NASA stated that the ozone hole over the Antarctic began appearing on a yearly basis in the 1980s, attributable to ozone-depleting chemicals (chlorofluorocarbons or CFCs), according to scientists. NOAA explained further that the hole forms in September and October.
According to NASA, the hole reached its maximum size for the year (8.2 million square miles) on Sept. 22. The largest the hole has ever been was on Sept. 6, 2000, at 11.5 million square miles. Watch this animation showing formation of the ozone hole over Antarctica in recent months:
"The ozone hole mainly is caused by chlorine from human-produced chemicals, and these chlorine levels are still sizable in the Antarctic stratosphere," NASA atmospheric scientist Paul Newman of NASA's Goddard Space Flight Center said in a statement. "Natural fluctuations in weather patterns resulted in warmer stratospheric temperatures this year. These temperatures led to a smaller ozone hole."
NASA reported a change in concentration of the ozone layer above the Antarctic being observed as well. Both NASA and NOAA observe the ozone regularly as it is Earth's shield from the sun's UV radiation.
According to NASA, ozone holes and global warming are related to an extent. It noted that the CFCs that cause ozone depletion are minor players in the greenhouse gas effect.
In the South Pole specifically, the greenhouse gases absorb heat at lower altitudes keeping the surface warm but leading cooler temps at higher levels in the atmosphere. This cooling, NASA wrote, results in more high, level clouds, which increase the reactions of CFCs to deplete the ozone.
This image represents the 2006 average size of the ozone hole (2006 held the largest average size of the hole). (Image: YouTube screenshot)
Newman expects that if a reduction in these CFCs continues, then the ozone layer at this location could return to 1980s levels sometime around 2065. NASA stated that adherence to the Montreal Protocol, an international treaty regulating CFCs, has helped protect ozone.
If the ozone layer is coming back, a report earlier this year from the universities of Bristol, Utrecht, California and Alberta found it might not have the most positive of environmental effects. The researchers created a model showing that methane could be trapped in the Antarctic sea ice. If an unusual amount of ice begins to melt, the persistent greenhouse gas could be released into the atmosphere only furthering the effects of global warming.