There is some good news coming from NASA. The space agency reported that the giant hole in the Earth’s protective ozone layer is shrinking and was the smallest observed since 1988. NASA got these results from measurements taken by the satellites.
On September 11, the ozone layer got the largest hole of the year measuring about 7.6 million square miles wide, about two and a half times the size of the United States. But the surprising thing was that it was still 1.3 million square miles smaller than last year. It then shrunk further during rest of September and October. NOAA ground- and balloon-based measurements also showed the least amount of ozone depletion above Antarctica during the peak of the ozone depletion cycle since 1988. Actually, NASA and NOAA have collaborated with each other to monitor the growth and recovery of the ozone hole every year. They have found that warmer than usual weather conditions in the stratosphere were primarily responsible for this shrinkage of the ozone hole. Scientists at NASA informed that the warmer air helped drive away chemicals like chlorine and bromine that deplete the ozone layer. But still, global efforts since mid-1980s to ban emission of ozone-depleting chemicals has been the main contributor towards this record smallest peak of the ozone hole.
Paul A. Newman, chief scientist for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland said that the Antarctic ozone hole was exceptionally weak this year and it was expected beforehand owing to the warmer weather conditions in the Antarctic stratosphere. These warmer temperatures slowed down ozone loss. Scientists informed that the smaller ozone hole extent in 2016 and 2017 occurred due to natural variability and it is not a signal of rapid healing. Although the warmer-than-average stratosphere led to the shrinkage in ozone hole, the current ozone hole area is still very large because the ozone-depleting substance like bromine and chlorine are still present in large amount and contribute to the ozone loss.
NASA and NOAA monitor the ozone hole via three complementary instrumental methods. Satellites such as NASA’s Aura satellite and NASA-NOAA Soumi National Polar-orbiting Partnership satellite measure ozone from space. NOAA scientists monitor the thickness of the ozone layer and its vertical distribution above the South Pole station by regularly releasing weather balloons carrying ozone-measuring “sondes” up to 21 miles in altitude, and with a ground-based instrument called a Dobson spectrophotometer. This latest news about record ozone hole shrinkage comes just after the 30th anniversary of the hole’s discovery, which led to the 1987 Montreal Protocol- a revolutionary international agreement that led to major effective global efforts to phase out the use of ozone-depleting chemicals.