Record-breaking hole in ozone layer over
Arctic closed: EU sat
By : TNN | Apr 27, 2020, 06.13 AM IST
In a good news, European satellite system
Copernicus has found that a record-breaking hole ever observed in the ozone
layer over Arctic has closed.
In late March, scientists had spotted
signs of a hole forming and it was thought to be the result of low temperatures
at the north pole. The ozone layer shields the Earth from most of Sun’s
ultraviolet radiation, a major cause of skin cancer. The largest hole ever
detected would only have posed a direct threat to humans if it had moved
further south to populated areas. But recently (on April 23), Copernicus earth
observation satellite system, comprising a constellation of six families of
satellites (Sentinels) and dozens of third party satellites, found the hole had
closed.
However, the closing has nothing to do
with the reduction in pollution caused by Covid-19 lockdown in several
countries. Instead, it's due to the polar vortex, the high-altitude currents that
normally bring cold air to the polar regions. This has split in two giving the
Arctic region a relative heatwave, with temperatures up to 20ºC higher than is
normal for this time of year. This year the polar vortex was extremely powerful
and temperatures inside it had been very cold. This generated stratospheric
clouds that destroy the ozone layer by reacting with chlorofluorocarbon (CFC)
gases. However in recent days, the polar vortex had broken up and weakened.
The first time an ozone hole was observed
at the North Pole was in 2011, but it was smaller and during the month of
January.
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