NASA Watches 30 Years of Ozone Success

Music: Life Choices by Eric Chevalier [SACEM]Complete transcript available. The ozone hole grew reached its annual maximum on Sept. 8, 2019. Every year, NASA and NOAA track the hole in the ozone layer over Antarctica as it grows to its annual winter maximum. This year, the hole was smaller than expected, due to an unusual weather pattern in the stratosphere. Related pages

Complete transcript available. Using measurements from NASA’s Aura satellite, scientists studied chlorine within the Antarctic ozone hole over the last several years, watching as the amount slowly decreased.This is the first definitive evidence of the success of the Montreal Protocol on Substances that Deplete the Ozone Layer, which was ratified in 1987. The international treaty banned the use of chlorofluorocarbons and related compounds, which break down in the stratosphere and release chlorine molecules. This chlorine depletes the ozone layer and is responsible for creating the hole in the ozone layer over Antarctica.The ozone hole fluctuates each year, reaching an annual maximum at the end of southern winter, usually in September. The hole has been trending smaller for the last few years, but as temperature has an effect on ozone-depletion, this was not definitive evidence of the Montreal Protocol’s efficacy. Although scientists have been measuring levels of chlorine near the ground for decades, this study is the first time anyone accurately measured chlorine levels inside the ozone hole, confirming that the Montreal Protocol is doing its job. Related pages