On April 6th, European Space Agency (ESA) scientists have noticed a strong reduction of ozone concentrations over the Arctic using the data from the Copernicus Sentinel-5P satellite.
They found some unusual atmospheric conditions including freezing temperatures in the stratosphere which have led ozone levels to collapse, causing a hole in the ozone layer.
What is an Ozone Layer?
Ozone layer is a shield on Earth’s stratosphere which protects us from the harmful ultraviolet radiations from the sun.
What is a Ozone Hole?
In simple terms, Ozone hole is the gap created due to the depletion on the ozone layer which is allowing the harmful radiations to pass through it.
The ozone holes are commonly found near Antarctica forming every year during autumn. From several weeks, using the data from the Tropomi instrument on the Copernicus Sentinel-5P satellite scientists were monitoring the formation of the holes over the Arctic.
• The Tropomi instrument on the Copernicus Sentinel-5P satellite measures a number of trace gases, including aerosol and cloud properties with a global coverage on a daily basis.
How these Ozone holes were formed?
Through studies over the Antarctica, scientists says that the ozone holes is caused by extremely cold temperatures (below -80°C), sunlight, powerful winds and Chlorofluorocarbons (CFCs).
This year when the polar winter ends, the first sunlight over the North Pole started this unusual strong ozone depletion causing the hole to form. In the past, small ozone holes have occasionally been spotted over the North Pole, but the depletion over the Arctic this year is much larger compared to previous years.
According to Diego Loyola (DLR), the maximum extension size of this year’s Arctic hole is less than a million sq. km which is quite smaller than the 25 million sq km hole of the Antarctic. Temperature in Arctic usually don’t go that low but this year powerful winds flowing around the North Pole trapped cold air within it (which is known as the ‘polar vortex’ ,a circling whirlpool of stratospheric winds).
Scientists using data from @CopernicusEU #Sentinel-5P have noticed a reduction of ozone concentrations over the Arctic. Unusual atmospheric conditions have led ozone levels to plummet – causing a ‘mini-hole’ in the ozone layer ???? https://t.co/6Qnz1ldVVx @ESA_EO pic.twitter.com/khwx0ummnl
— ESA (@esa) April 6, 2020
Diego says, “Since 14 March, the ozone columns over the Arctic have decreased to what is normally considered ‘ozone hole levels,’ which are less than 220 Dobson Units. We expect the hole to close again during mid-April 2020″.