The ozone hole over Antarctica opened unusually early this year. Scientists believe this may be due to the devastating eruption of Hunga Tonga Volcano that shook the world in January 2022.

The development is not unexpected. Earlier this year, ozone experts predicted the explosion would happen. threw In the years following the explosion, 50 million tons (45 million tons) of water vapor into the Earth’s atmosphere is likely to affect the Earth’s protective ozone layer.

Condensation of water vapor in the stratosphere, the second lowest layer Earth’s atmosphereIt increased by 10 percent due to the eruption of the underwater volcano where the ozone layer is located. According to Paul Newman, chief scientist of the Atmospheric Research Division at NASA’s Goddard Space Flight Center, this led to “significant cooling” in the stratosphere; This is bad news for ozone levels.

The data show that the size of the ozone hole in August 2023 is the 10th largest on record. The size of the hole is currently more than 6 million square miles (16 million square kilometers). It will continue to rise until the end of September, when Antarctica begins warming as it enters the spring season. It will take at least until the end of November for the hole to close, but it could take much longer.

Stratospheric cooling resulting from increased water vapor concentration in the stratosphere leads to more frequent formation of polar stratospheric clouds. Scientists believe these spooky rainbow clouds, forming at an altitude of 9 to 15 miles (15 to 25 kilometers), create the right chemical environment for ozone-depleting substances (ODS) in the stratosphere to do their destructive work. Although many of these substances, such as chlorofluorocarbons and hydrofluorocarbons previously used in aerosol sprays and refrigerants, are banned by Montreal. protocol They take decades to naturally decay in 1987 and their concentrations in the atmosphere are still high.

While researchers can’t say for certain whether Hunga Tonga is responsible for this year’s above-average ozone depletion, they hope to learn more from the measurements, Vincent-Henri Peuch, director of the Copernicus Atmosphere Monitoring Service (CAMS), said in a statement. next months.

“Our ability to provide three-dimensional analyzes and predictions of polar ozone is a powerful approach to monitoring in real time how ozone holes are evolving and evaluating what the key factors are,” said Peuch. “This gives us an idea of ​​the extent to which certain events, such as last year’s Hung Tonga Haapai eruption, which increased the amount of water vapor in the stratosphere, have impacted the development of the Antarctic ozone hole this year.”

The aftermath of the Hunga Tonga Volcano eruption is an entirely new field for scientists; because no volcanic eruption before in recorded history has released so much water into the atmosphere. But other factors also play a role when it comes to the unusual behavior of the ozone layer, according to Copernicus.

Very large and long-lasting ozone holes were seen in the previous three years, but these holes opened later in the season compared to this year. Scientists believe that despite the gradual decrease in the concentration of ozone-depleting substances in the atmosphere, progressive climate change may contribute to ozone depletion. Processes in the atmosphere are complex, and models show that while temperatures near the Earth’s surface are definitely increasing, the stratosphere is actually cooling (even without the extra water from Hung Tong), which means more ozone depletion.

“The previous three years were characterized by strong and persistent Antarctic stratospheric polar vortices, and the ozone holes were some of the largest and longest on record,” Copernicus said in a statement. said. “This does not mean that the Montreal Protocol to ban the use of ozone-depleting substances does not work. On the contrary, the destruction of the ozone layer would have been even more powerful if it had not been for the prohibition in these circumstances.” Source