VATIS UPDATE Article

According to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) who monitor the annual phenomenon, the hole in the Earth’s ozone layer that forms over Antarctica each September grew to about 8.9 million square miles in 2016 before starting to recover. “This year we saw an ozone hole that was just below average size. What we’re seeing is consistent with our expectation and our understanding of ozone depletion chemistry and stratospheric weather,” said Paul A. Newman, at NASA.

At its peak on September 28, the ozone hole extended across an area nearly three times the size of the continental United States. In 2015 the ozone hole grew to 10.9 million square miles, 2 million square miles larger than this year, before returning to relatively normal summer levels. Its larger size last year was due to colder-than-average temperatures in the stratosphere that amplified the destruction of ozone by sunlight reacting with chlorine and bromine from man-made chemicals. In 2016, warmer stratospheric temperatures constrained the growth of the ozone hole.

During the 1960s, before the Antarctic ozone hole occurred, average ozone concentrations above the South Pole ranged from 260 to 320 Dobson units. This year’s Antarctic ozone hole is similar to the 2013 hole which reached 9.3 million square miles. Although warmer than average stratospheric weather conditions reduce ozone depletion, the current ozone hole area is large compared to the 1980s, when the depletion of the ozone layer above Antarctica was first detected. This is because levels of ozone-depleting substances (ODS) remain high enough to produce significant ozone loss.