Scientists say the continuous cold temperatures and strong winds have helped shape the large and deep Antarctic ozone hole, which should last until November.
According to a report by the U.S. National Oceanic and Atmospheric Administration (NOAA) and NASA scientists, the annual ozone hole in the Antarctic reaches a maximum of about 24.8 million square kilometers, about three times the size of the U.S. continent.
Observations have revealed that ozone is almost completely eliminated in a four-mile-high column of the stratosphere above the Antarctic.
Scientists say that by 2020, the satellite record will be the 12th largest ozone hole in the region in 40 years, ranking 14th in the 33-year-old ozone-depleting sphere.
The continued decline in the level of ozone-depleting chemicals under the Montreal Convention has prevented the hole from growing as large as it did in the same weather conditions decades ago.
“Since reaching its peak in 2000, the amount of stratospheric chlorine and bromine in the Antarctic has dropped by about 16% to its natural level,” said Paul Newman, a global scientist at the Goddard Space Center at the NASA’s Greenbelt Space Center in Greenbelt, Maryland.
“We have a long way to go, but this improvement has made a big difference this year. “If the layer had as much chlorine as it did in 2000, the hole would have been about a million square miles.”
Ozone is made up of three oxygen atoms and is very active with other chemicals.
At about seven to 25 miles above the Earth’s surface, the ozone layer acts like sunscreen, protecting the Earth from ultraviolet light, which can cause skin cancer and white eyes, suppress the immune system, and suppress plant and plant food sensitivities. Chain.
By comparison, ozone is formed closer to the surface by a photochemical reaction between sunlight and vehicle emissions and other sources of pollution.
In the winter of the Southern Hemisphere, the Antarctic ozone hole is formed, and the returning sunlight begins the ozone depletion reaction.
The cold winter temperatures that continue in the spring trigger the process of ozone depletion, which is why “holes” form in the Antarctic.
These reactions are caused by chemically active compounds of chlorine and bromine.
The chemicals that cause their formation include chemical reactions that occur on the surface of cloud particles formed in the cold layer, eventually leading to an escape reaction that destroys the ozone molecule.
In warmer temperatures, clouds at the pole layer are few, which do not last long, limiting the process of ozone depletion.
Brian Johnson, a scientist at the NOAA Global Monitoring Laboratory, said the ozone depletion rate slowed in September compared to 20 years ago, which is consistent with low levels of chlorine in the atmosphere.