hole Ozone About Antarctica It forms later this year than usual, and is associated with two episodes of rising temperatures in the Antarctic winter (our summer) and changes in the pattern of stratospheric winds. But this delay should not be read directly as a sign of recovery from the ozone hole, Copérnico, a Climate change and the European Union Earth Observation.
The Notice Copernicus was created on Monday 16 September, which marks the International Day for the Protection of the Ozone Layer, which celebrates the most successful environmental agreement: the Montreal Protocol, signed in 1987, which led to the end of the use of destructive chemicals. Ozone layer. Ozone forms a protective blanket that protects life on Earth from the sun’s dangerous ultraviolet radiation.
Under normal weather conditions, the ozone hole begins to form in mid or late August and lasts until the end of November, when it begins to close. But this year, it is developing much more slowly due to disturbances in the polar vortex – a large low-pressure area located over each pole of our planet, containing large amounts of cold air and generating winds of up to 300 km/h. .
Hole in the ozone layer in Antarctica
CAMS/ECMWF
The disturbances are two episodes of sudden warming in July and August in the stratosphere, about 30 km above the icy continent, the Copernicus press release explains.
The usual temperature in Antarctica’s upper stratosphere in July is minus 80 degrees Celsius, but on July 7, there was a 15-degree jump, setting a record for the month at that location, according to a report from the North American Space Agency. NASA.
From July 22 the cold returned to normal, but on August 5 there was another leap towards warmth: the temperature rose by 17 degrees. All this during the summer in Antarctica.
“The July episode was the most anticipated warming in the stratosphere [sobre a Antárctida]”In 44 years of observations by scientists at NASA’s Goddard Space Flight Center, Lawrence Coy, an atmospheric scientist at the research center, was quoted in a report by the US space agency.
This warming disturbed the polar vortex, which elongated rather than circling. This reduced wind speed and led to warming of the stratosphere. This type of event only happens more or less every five years in Antarctica Arctic Very common.
The Copernicus report states that while the polar vortex weakens with higher temperatures and slower winds in the stratosphere, the ozone depletion process is less aggressive. So, instead of the ozone hole starting to form in August, it usually dragged on until September.
Currently, the ozone concentration in Antarctica is still around 220 Dobson units. From there the ozone hole is thought to start forming.
What else needs to be done?
Can we read that there is a redemption in this event? The trend has been positive in recent years, but it has not been easy. “An exceptionally cold period reveals nothing about the long-term trend Climate“The slow onset of ozone depletion cannot automatically be attributed to the recovery of the ozone layer or the successful abandonment of ozone-depleting chemicals,” the Copernicus report cautions.
Even if the Montreal Protocol succeeds, stratospheric ozone-depleting chemicals remain in the atmosphere and will take decades to reduce to pre-industrial levels. And, in the meantime, they will continue to influence the growth of the ozone hole – along with weather factors and pollutants released by humans, in addition to the impact of climate change.
Other factors that accelerate ozone depletion include smoke from large forest fires, steam and sulfur oxides from volcanic eruptions. And some ozone-depleting gases, such as hydrofluorocarbons (HFCs), also have a powerful screening effect. International Committee for the Protection of the Ozone Layer
The Kigali Amendment to the Montreal Protocol focuses on phasing out HFCs, but there are problems with its implementation, and even the smuggling of these gases, including to Europe.
“If fully implemented, we can limit warming to 0.5 degrees Celsius by the end of this century,” said UN Secretary-General Antonio Guterres. World Meteorological Organization In connection with the International Day for the Preservation of the Ozone Layer.
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