Measurements from satellites this year showed the hole in Earth’s ozone layer that forms over Antarctica each September was the smallest observed since 1988, scientists from NASA and NOAA announced today.
According to NASA, the ozone hole reached its peak extent on September 11, covering an area about two and a half times the size of the United States – 19.6 million km2 (7.6 million mi2) in extent – and then declined through the remainder of September and into October. NOAA ground- and balloon-based measurements also showed the least amount of ozone depletion above the continent during the peak of the ozone depletion cycle since 1988. NOAA and NASA collaborate to monitor the growth and recovery of the ozone hole every year.
“The Antarctic ozone hole was exceptionally weak this year,” said Paul A. Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This is what we would expect to see given the weather conditions in the Antarctic stratosphere.”
This year’s ozone hole was similar in area to the hole in 1988, about 1 million miles smaller than in 2016. Although scientists predict the ozone hole will continue to shrink, this year’s smaller ozone hole had more to do with weather conditions than human intervention. Credit: NASA’s Goddard Space Flight Center/Kathryn Mersmann
The smaller ozone hole in 2017 was strongly influenced by an unstable and warmer Antarctic vortex – the stratospheric low pressure system that rotates clockwise in the atmosphere above Antarctica. This helped minimize polar stratospheric cloud formation in the lower stratosphere. The formation and persistence of these clouds are important first steps leading to the chlorine- and bromine-catalyzed reactions that destroy ozone, scientists said. These Antarctic conditions resemble those found in the Arctic, where ozone depletion is much less severe.
H/t reader squodgy:
“The thin layer of ozone above our planet is to protect us,
but holes appeared in it back in the 70’s.
The guilt trippers blamed CFC’s in aerosols, so they were banned. But nothing changed, till now.
So, now the ozone hole is shrinking over the Arctic
It’s also shrinking over the Antarctic.
Once again it begs the question…
” Is it a natural cycle?”
and is all the scaremongering typical media hype to sell papers & air time?”
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