A giant ozone hole opened over Antarctica this year. Already larger than the entire ice-covered continent, the ozone hole has surpassed the size of 75% of ozone holes measured since 1979 and continues to grow. Scientists believe climate change may be the cause.
“To fully understand the link between the ozone layer and climate change, there is still research to be done, but we do know that there is a link between ozone depletion and temperature,” said Vincent-Henri Peuch, director of the European Union’s Copernicus Atmospheric Monitoring Service, which published the data.
While temperatures on the planet’s surface are rising, the stratosphere, where the protective ozone shield is located, is cooling. The stratosphere, a layer of Earth’s atmosphere 10 to 50 kilometers high, is where so-called polar stratospheric clouds form in winter. Today, scientists know that these clouds create the perfect chemical environment for harmful substances based on chlorine and bromine to do their destructive work. They also know that the colder the temperature in the stratosphere, the more polar stratospheric clouds form, Pach said.
“Sometimes the ozone hole is small because there are no polar stratospheric clouds, and sometimes when there are a lot of them, it tends to be bigger,” Peitsch said. “With more polar stratospheric clouds, chlorine and other harmful substances can act more effectively and cause more damage, even as their concentrations decrease.”
Pach says the size of the ozone hole varies significantly from year to year, and trends are hard to capture. This year, the ozone hole already covers 22 to 23 million square kilometers. Peitch predicts the hole will continue to grow until early October, when temperatures in the Southern Hemisphere begin to rise.
The Copernicus Atmospheric Monitoring Service uses data from several satellites that determine the stratospheric ozone content by measuring the ultraviolet and infrared components of sunlight passing through the atmosphere. The less ozone, the more ultraviolet and infrared light passes through the atmosphere. Sophisticated computer models then combine the data, as in weather forecasting.
According to Peitsch, researchers are still trying to understand the relationship between the Earth’s climatic phenomena and processes in the stratosphere. So it is impossible to say whether the unprecedented heat waves in many regions of the world this year and the gaping ozone hole are related.
