‘Bigger than usual’: this year’s ozone hole is bigger than Antarctica

‘Bigger than usual’: this year’s ozone hole is bigger than Antarctica

The ozone hole that grows each year is “rather bigger than usual” and is currently larger than Antarctica, say scientists monitoring it.

Researchers from the Copernicus Atmosphere Monitoring Service say this year’s hole is growing rapidly and is larger than 75% of ozone holes at this point in the season since 1979.

Ozone exists about 11 to 40 km above the Earth’s surface, in the stratosphere, and acts as a sunscreen for the planet, protecting it from ultraviolet rays. Each year, a hole forms at the end of winter in the southern hemisphere as the sun causes ozone depletion reactions, which involve chemically active forms of chlorine and bromine derived from compounds man-made. In a statement, Copernicus said this year’s hole “has become a rather bigger hole than usual”.

Vincent-Henri Peuch, the director of the service, told the Guardian: “We cannot really say at this stage how the hole in the ozone layer will develop. However, this year’s hole is remarkably similar to that of 2020, which was among the deepest and most enduring – it closed around Christmas – in our archives since 1979.

“The 2021 ozone hole is now among the highest 25% of our records since 1979, but the process is still ongoing. We will continue to monitor its development in the coming weeks. A large or small ozone hole in a year does not necessarily mean that the overall recovery process is not going as planned, but it can signal that special attention needs to be paid and that research can be directed to investigate the problems. reasons for a specific ozone hole event. “

Scientists admit that the depletion of the ozone layer is caused by man-made gases called CFCs, which were first developed in the 1930s for use in refrigeration systems and were later deployed as propellants in aerosol cans. The chemicals are stable and therefore can travel from the Earth’s surface to the stratosphere. But then, at the altitude where the stratospheric ozone is found, they are broken down by high energy UV radiation. The ensuing chemical reactions destroy the ozone. CFCs have been banned in 197 countries around the world.

Since the ban on the so-called halocarbons, the ozone layer has shown signs of recovery, but it is a slow process and it will be until the 2060s or 70s for a complete phase out of depleting substances. In recent years, under normal weather conditions, the ozone hole has typically reached a maximum of 20 million km² (8 million square miles).

The 2020 Arctic ozone hole was also very large and deep, and peaked at about three times the size of the continental United States.

The Antarctic ozone hole typically peaks between mid-September and mid-October. When temperatures start to rise in the stratosphere in the late spring of the southern hemisphere, ozone depletion slows down, the polar vortex weakens and eventually breaks down, and by December levels of ozone usually returns to normal.


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