The annual Antarctic ozone hole reached an average area of 8.9 million square miles (23.2 million square kilometers) between September 7 and October 13, 2022. This depleted zone of ozone above the South Pole was slightly lower than last year and generally continued the general downward trend of recent years.
“Over time, steady progress is being made and the hole is getting smaller,” said Paul Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re seeing some hesitation as weather changes and other factors cause the numbers to fluctuate slightly from day to day and week to week. But overall, we’re seeing a decrease in over the past two decades. Eliminating ozone-depleting substances through the Montreal Protocol is shrinking the hole.”
The ozone layer – the part of the stratosphere that shields our planet from the sun’s ultraviolet rays – thins to form an “ozone hole” above the South Pole each September. Chemically active forms of chlorine and bromine in the atmosphere, derived from man-made compounds, attach themselves to high-altitude polar clouds each southern winter. The reactive chlorine and bromine then trigger ozone-destroying reactions when the sun rises at the end of the Antarctic winter.
NASA and NOAA researchers detect and measure the growth and rupture of the ozone hole with instruments aboard the Aura, Suomi NPP and NOAA-20 satellites. On October 5, 2022, these satellites observed a one-day maximum ozone hole of 10.2 million square miles (26.4 million square kilometers), slightly larger than last year.
When the polar sun rises, NOAA scientists also make measurements with a Dobson spectrophotometer, an optical instrument that records the total amount of ozone between the surface and the edge of space, known as the total value. of the ozone column. Overall, the total column average is about 300 Dobson units. On October 3, 2022, scientists recorded the lowest column total ozone value of 101 Dobson units above the South Pole. At this time, ozone was almost completely absent at altitudes between 8 and 13 miles (14 and 21 kilometers) – a very similar trend to last year.
Some scientists were concerned about the potential stratospheric impacts of the January 2022 eruption of the Hunga Tonga-Hunga Ha’apai volcano. The eruption of Mount Pinatubo in 1991 released substantial amounts of sulfur dioxide which amplified the depletion of the ozone layer. However, no direct impact from Hunga Tonga has been detected in the Antarctic stratospheric data.
The hole in the Antarctic ozone layer is the 13th largest on record and is expected to persist until November
View the latest state of the ozone layer over Antarctica with NASA’s Ozone Watch.
Quote: Ozone hole continues to shrink in 2022, say NASA and NOAA scientists (2022, October 26) Retrieved October 26, 2022 from https://phys.org/news/2022-10-ozone -hole-nasa-noaa-scientists.html
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