Unusual Winds Drive a Small 2019 Ozone Hole

Every year, the ozone hole over Antarctica reaches an annual maximum extent during southern winter. The depletion of ozone by chlorofluorocarbons (CFCs) happens faster at colder temperatures and slows down as temperatures warm, so each October, the ozone layer begins to heal again for the year.Scientists from NASA and NOAA work together to track the ozone layer throughout the year and determine when the hole reaches its annual maximum extent. This year, the South Pole region of Antarctica was slightly colder than the previous few years, so the ozone hole grew larger. However, scientists from NASA have developed models to predict what the ozone layer would have looked like without the Montreal Protocol, which banned the release of CFCs. Although the 2018 hole was slightly larger than that of 2017 or 2016, it was still much smaller than it would have been without the Montreal Protocol. Music: Saturn Echoes by Eddy Pradelles [SACEM]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. Complete transcript available.

NASA and NOAA scientists work together to study the ozone layer, monitoring the hole over Antarctica as it fluctuates with the seasons.This year, the ozone hole s been since 1988. The hole in the ozone layer is caused each year as ozone molecules react with chlorofluorocarbons (CFCs) in the atmosphere. The reactions occur at cold temperatures, so the hole reaches a maximum size each year at the end of southern winter, and then heals during the warmer summer months. Although CFCs have been banned since 1987 under the Montreal Protocol on Substances that Deplete the Ozone Layer, the compounds decay very slowly, and still remain in the atmosphere. This year, the small ozone hole was mostly caused by warmer temperatures, which slowed down the reactions between ozone and CFCs. Music: Stars Align by Andrew Michael Britton [PRS]

Thirty years ago, the nations of the world agreed to the landmark ‘Montreal Protocol on Substances that Deplete the Ozone Layer.’ The Protocol limited the release of ozone-depleting chlorofluorocarbons (CFCs) into the atmosphere. Since the 1960s, NASA scientists have worked with NOAA researchers to study the ozone layer, using a combination of satellite, aircraft and balloon measurements of the atmosphere.Things have been improving in the 30 years since the Montreal Protocol. Thanks to the agreement, the concentration of CFCs in the atmosphere has been decreasing, and the ozone hole maximum has been smaller since a record in 2006.From the ground and space, NASA science offers a unique perspective of Earth, helping to identify challenges and find solutions to benefit the planet. Music: Future Generation by Laurent Dury [SACEM]