Hunga Tonga underwater volcano eruption likely to widen ozone hole in coming years (2023)

The Hunga Tonga volcanic eruption that stunned the world last January threw so much water into the stratosphere that it is likely to widen the hole in the ozone layer for years to come, scientists believe.

According to reports, the powerful eruption that wasseen from spaceedetectable by all types of sensorsaround the world, the increasedamount of water in the stratosphereat 10%. The stratosphere is the second lowest layer of theatmosphere of the earthand there is the ozone layer, which protects the planet from harmful ultraviolet radiation.

Now, ozone could be at risk because water ejected from Hunga Tonga volcano "has caused significant stratospheric cooling in the south-mid latitudes," Paul Newman, chief scientist for atmospheric science at NASA's Goddard Space Flight Center, told Space. .with.

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Lower temperatures in the stratosphere are accelerating the process of ozone depletion, Vincent Henri Peuch, head of Europe's Copernicus Atmosphere Monitoring Service, told Space.com. Because when the stratosphere is cooler and there is a lot of water at these altitudes, scientists observe the more frequent formation of polar stratospheric clouds, fine, mysterious clouds that float 15 to 25 kilometers above the Earth. Forming during the winter months when temperatures in the stratosphere are at their coldest, these clouds provide the right chemical environment for chlorine-based ozone-depleting substances, which were banned in 1989 but still linger in the air over the planet to destroy ozone .

"During the polar night, a pre-processing of the chlorinated compounds takes place in the polar stratospheric clouds," said Peuch. "It works throughout the Antarctic winter in July and August, and when the light returns in the polar regions in September, all that pre-processing turns into ozone depletion, which we see as the hole in the ozone layer."

Once the stratosphere warms, when the Antarctic summer arrives, the hole in the ozone layer begins to close and usually disappears by the end of November.

Although the Hunga Tonga eruption occurred in January, scientists have observed no impact on this year's ozone hole. Therefore, scientists' eyes are on the coming year. Newman said that while it's speculative to predict Hunga Tonga's impact on the Antarctic ozone hole over the next year, he's fairly confident scientists will see a difference.

"The material from Hunga Tonga has not entered the ozone hole over Antarctica this year, but it certainly will get there next year," Newman said. "And just from a simple estimate, I would say the effect will be detectable and quite large. Of course, the Antarctic stratosphere varies from year to year, so there's always a chance we'll have some weird stratospheric circulation. This next year and the impact of Hunga Tonga won't be obvious, but I think it will be."

However, scientists are not concerned about this temporary enlargement of the hole in the ozone layer. According to the latestRating of the World Meteorological Organization(opens in new tab)(WMO), the Earth's protective ozone layer, located at elevations between 9 and 21 miles (15 and 35 km), is recovering from depletion caused by chlorine- and bromine-containing chemicals used in aerosols since the 1950s and coolants are used in the depletion of the ozone layer and the hole that opened up over Antarctica in the 1970s, and quickly found the culprit. The most harmful ultraviolet radiation passed through the weakened ozone layerTerra' Pop up.Estimate of studiesthat in Australia, the continent hardest hit by ozone depletion, the incidence of melanoma, a type of skin cancer associated with damage from ultraviolet light, increased by 60% between 1982 and 2010.

The use of the offending substances was banned by the Montreal Protocol, signed by the United Nations in 1987. According to the new assessment released Jan. 8, the world's ozone layer is expected to largely heal over the next two decades. It will take a little longer for the hole in the Antarctic ozone layer to fully close, but scientists expect it to disappear by the mid-2060s.

Despite the Montreal Protocol's success in averting one of mankind's worst self-inflicted environmental disasters, satellite measurements show that theThe ozone hole over the Antarctic could still reach considerable sizesand last until the Antarctic summer. The ozone hole has been surprisingly large for the past three years, according to Europe's environmental monitoring program Copernicus, remaining open until December, where it normally closes in late November.

This unusual behavior could be due to fluctuations in the size and strength of the polar vortex, the area of ​​strong cold winds over the Earth's poles, Peuch said. These changes that may resultof climate change, sometimes lead to colder conditions in the polar vortex, which in turn leads to a larger, longer-lasting ozone hole. While the Antarctic ozone hole could join its three large, long-lived predecessors in 2023, perhaps with the help of water vapor from Hunga Tonga, scientists are confident that we will see the ozone hole shrink in the long term.

"We don't understand exactly what's driving these year-to-year fluctuations," Peuch said. "It's like climate. One year the stratosphere will be colder than next year. There are warmer periods and colder periods, and with that you have different patterns of variability in the size of the ozone hole. It's still an area of ​​research. "

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