By James R. Riordon – NASA Goddard Space Flight Center
The atmosphere over Antarctica continues to heal: The annual hole in the ozone layer over Earth's Antarctic in 2024 will be relatively small compared to other years. Scientists from NASA and NOAA predict that the ozone layer may fully recover by 2066.
NASA Earth Observatory/Lauren Dauphin
During the peak ozone depletion period from September 7 to October 13, the ozone hole in 2024 was the seventh smallest since recovery began in 1992, when the Montreal Protocol, a landmark phase-out of ozone-depleting chemicals The international agreement on goods has come into effect.
The average monthly ozone-depleting area in Antarctica this year is nearly 8 million square miles (20 million square kilometers), nearly three times the size of the continental United States.
Scientists say the improvement is due to continued reductions in harmful chlorofluorocarbon (CFC) chemicals, as well as accidental injections of ozone carried by air currents from northern Antarctica.
From September 7 to October 13, 2024, the average area of the ozone hole over Antarctica was nearly 8 million square miles (20 million square kilometers), making it the 20th smallest hole in 45 years.
Image credit: NASA Goddard Space Flight Center/Kathleen Gaeta
In previous years, ozone hole rankings reported by NASA and NOAA used time frames dating back to 1979, when scientists began using satellite data to track Antarctic ozone levels. According to the longer record, this year's hole ranks 20th largest in 45 years of observations.
“The Antarctic hole in 2024 will be smaller than the ozone hole that existed in the early 2000s,” said Paul Paul, leader of NASA's ozone research team and chief earth science scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Newman said. “The gradual improvements we have seen over the past two decades suggest that international efforts to curb ozone-depleting chemicals are working.”
The ozone-rich layer in the upper atmosphere acts as a planetary sunscreen, helping protect us from harmful ultraviolet (UV) radiation from the sun. Areas with poor ozone layers are exposed to more UV radiation, leading to increased cases of skin cancer and cataracts. Overexposure to UV light also reduces agricultural yields and harms aquatic plants and animals in important ecosystems.
In the 1970s, scientists were alarmed by the prospect of CFCs eroding atmospheric ozone. By the mid-1980s, the ozone layer had become so depleted that by early October each year, large areas of the Antarctic stratosphere were essentially ozone-free. Sources of damaging CFCs include coolants in refrigerators and air conditioners, and aerosols in hair spray, antiperspirants and spray paint. The manufacturing of insulating foam and components of industrial fire suppression systems also release harmful chemicals.
The Montreal Protocol was signed in 1987 to phase out CFC-based products and processes. Countries around the world agreed by 2010 to replace these chemicals with more environmentally friendly alternatives. But CFCs already in the air take decades to break down. As existing CFC levels gradually decline, ozone in the global upper atmosphere will rebound and the ozone hole will shrink.
Ozone 101 is the first in a series of explanatory videos outlining the basics of popular earth science topics. Let's go back to the basics and learn about the causes of the ozone hole, its impact on the Earth, and what scientists predict will happen in the coming decades.
Image credit: NASA Goddard Space Flight Center/Kathleen Gaeta
“By 2024, we can see that the ozone hole is less severe than other years in the past three decades, but the ozone layer is still far from intact,” said Stephen Monzca, senior scientist at NOAA's Global Monitoring Laboratory. Completely healed.
Researchers rely on a combination of systems to monitor the ozone layer. These include instruments on NASA's Aura satellite, NOAA-20 and NOAA-21 satellites, and the Suomi National Polar-Orbiting Partner satellite, jointly operated by NASA and NOAA.
NOAA scientists also released instrumental weather balloons from the Antarctic Baseline Atmospheric Observatory to directly observe ozone concentrations overhead in a measurement called Dobson units. On October 5, 2024, the concentration reached a minimum value of 109 Dobson units.
Observations of ozone concentrations by NASA and NOAA satellites cover the entire ozone hole, which can produce slightly smaller values for the lowest Dobson unit measurements.
“This is well below the 225 Dobson units that were typical for the ozone layer over Antarctica in 1979,” said Bryan Johnson, a research chemist at NOAA. “So to return atmospheric ozone to levels before widespread CFC pollution, there is still a long way to go.” A long way to go.”
Check the latest status of the ozone layer over Antarctica through NASA's ozone monitoring.
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