The ozone hole over Antarctica is now one of the largest ever recorded after reaching three times the size of Brazil, satellite data has revealed.
Worse, it could still exceed the 26 million square kilometers (10.3 million square miles) it measured on Sept. 16, because depletion typically doesn’t peak until mid-October.
Scientists aren’t sure why this year’s ozone hole is so large, but some researchers have speculated that it could be related to Tonga’s underwater volcanic eruption in January 2022.
Its explosion was equivalent to the most powerful nuclear test ever conducted by the United States and the largest natural explosion in more than a century.
The size of the ozone hole fluctuates periodically.
Gape: The ozone hole over Antarctica is now one of the largest on record after reaching three times the size of Brazil, satellite data revealed (pictured)
Each August, at the start of the Antarctic Spring, it begins to grow and peaks around October, before receding slightly and finally closing again.
This occurs because Antarctica enters its summer season and temperatures in the stratosphere begin to rise.
When this happens, the mechanism that depletes ozone and creates the hole slows down and eventually stops, preventing the hole from growing further.
The hole has closed later than normal over the past three years, partly due to the Black Summer bushfires in Australia in 2019-20, which released large amounts of smoke that destroyed the ozone layer.
It also opened several weeks earlier this year, in early August, and it’s unclear when it will safely close.
The depletion of the ozone layer on the frozen continent was first detected in 1985 and over the last 35 years several measures have been introduced to try to reduce the hole.
Experts are confident that the Montreal Protocol introduced in 1987 has helped recover the hole, but this year’s measurements by the European Copernicus Sentinel-5P satellite are a blow.
Antje Inness, senior scientist at the Copernicus Atmosphere Monitoring Service (CAMS), said: “Our operational ozone monitoring and forecasting service shows that the 2023 ozone hole started early and has grown rapidly since mid-August.
“It reached a size of more than 26 million square kilometers on September 16, making it one of the largest ozone holes ever recorded.”
He explained that Tonga’s underwater eruption could have been to blame.
“The eruption of the Hunga Tonga volcano in January 2022 injected a large amount of water vapor into the stratosphere, which only reached the south polar regions after the end of the 2022 ozone hole,” Dr Inness said.
“Water vapor could have caused increased formation of polar stratospheric clouds, where chlorofluorocarbons (CFCs) can react and accelerate the depletion of the ozone layer.
“The presence of water vapor can also contribute to the cooling of the Antarctic stratosphere, further favoring the formation of these polar stratospheric clumps and giving rise to a more robust polar vortex.”
Despite this theory, scientists caution that the exact impact of the eruption on the hole is still the subject of ongoing research.
However, there is precedent in this regard.
Theory: Scientists aren’t sure why this year’s ozone hole is so large, but some experts have speculated that it could be related to Tonga’s underwater volcanic eruption in January 2022.
The size of the ozone hole fluctuates periodically. Each August, at the start of the Antarctic Spring, it begins to grow and peaks around October, before receding slightly and finally closing again.
A challenge: the depletion of the ozone layer on the frozen continent was first detected in 1985 and over the last 35 years several measures have been introduced to try to reduce the hole.
In 1991, the Mount Pinatubo eruption released substantial amounts of sulfur dioxide that was later found to have amplified ozone layer depletion.
Ozone depletion depends on extremely cold temperatures, since only at -78°C (-108°F) can a specific type of cloud form, called polar stratospheric clouds.
These icy clouds contain ice crystals that convert inert chemicals into reactive compounds, devastating the ozone.
These are substances containing chlorine and bromine, which become chemically active in the icy vortex rotating over the south pole.
These were produced in large quantities in the late 20th century, when halocarbons such as CFCs and hydrochlorofluorocarbons (HCFCs) were commonly used as refrigerants in refrigerators and aerosol cans.
Ozone depletion depends on extremely cold temperatures, since only at -78°C can a specific type of cloud form, called polar stratospheric clouds. This 3D graph shows how the ozone hole over Antarctica has changed during 2023, with a snapshot from July
Comparison This image above captures what the ozone was like in August of this year.
Near its peak: This image captures ozone when it reached a size of 26 million square kilometers
In response to this, the Montreal Protocol was created to protect the ozone layer by phasing out the production and consumption of these harmful substances.
Claus Zehner, director of the European Space Agency’s Copernicus Sentinel-5P mission, said this had led to a recovery of the ozone layer, adding: “Scientists currently predict that the global ozone layer will return to its normal state.” around 2050.”
Ozone is a compound made up of three oxygen atoms that occurs naturally in small quantities high in the atmosphere.
It is toxic to humans when ingested, but at its high altitude, up to ten miles above the Earth’s surface, it actually protects us from the harmful ultraviolet rays cast by the sun.
Launched in October 2017, the Copernicus Sentinel-5P satellite is the first of Europe’s Copernicus satellites dedicated to monitoring Earth’s atmosphere.
It has a state-of-the-art instrument that is capable of detecting atmospheric gases to obtain images of air pollutants with greater precision and with higher spatial resolution than ever from space.
