That Hole in the Earth’s Ozone Layer Is Closing

This is great news. It appears that all the efforts to repair that hole discovered in the Earth’s ozone layer located over the Antarctica is working. This is what was discovered in a brand new study that looks directly at the chemicals that have been destroying the ozone layer.  

The Earth’s ozone layer is critical as it is protects the surface of our planet from the most harmful rays from the sun. These are the rays which cause cataracts and cancer within human beings, and that damage plant life, as reported by NASA. During In the 1980s, scientists discovered a huge hole located in the ozone layer over the region of the Antarctica. It was determined that this was caused mainly by chemicals that are referred to as chlorofluorocarbons (CFCs) which were produced by humans. 

Satellite Confirmations

Prior observations from satellite have witnessed size changes in that ozone hole, taking note that it can shrink and grow from one year to the next. However this new study is the very first to measure changes in the chlorine levels — which the primary CFC byproduct that is responsible for the depletion of the ozone — in the atmosphere which lies above Antarctica. This study has indicated 20% decrease in the depletion of the ozone because of chlorine.

New Ozone Studies

This brand new study examined the ozone data that was collected between the years 2005 and 2016 by an instrument called the Microwave Limb Sounder (MLS) that is onboard the Aura satellite. This instrument is not able to directly detect the atoms of chlorine, rather it detects hydrochloric acid, which will forms whenever methane reacts with chlorine atoms, and then they bond with hydrogen. Whenever Antarctica is exposed to sunlight during the Southern Hemisphere’s long summer, the CFCs will break down and start producing chlorine, which will then bust apart the ozone atoms. However, during the winter months at Antarctica, this chlorine will then bind with methane “once all the ozone has been destroyed” within its vicinity. 

“By around mid-October, all the chlorine compounds are conveniently converted into one gas, so by measuring hydrochloric acid, we have a good measurement of the total chlorine,” stated the lead study author Susan Strahan, who is an atmospheric scientist from NASA’s Goddard Space Flight Center located in Greenbelt, Maryland.

This MLS instrument has directly observed the ozone hole every day throughout the Southern Hemisphere’s winter. 

“During this period, Antarctic temperatures are always very low, so the rate of ozone destruction depends mostly on how much chlorine there is,” Strahan added. “This is when we want to measure ozone loss.”

Since prior studies were dependent upon measurements of the ozone hole’s physical size, the study’s authors claim their research is the very first to show directly that this ozone depletion is lowering because of the decrease in chlorine levels from CFCs. The 20% reduction in the depletion is “very close to what our model predicts we should see for this amount of chlorine decline,” Strahan noted. 

“This gives us confidence that the decrease in ozone depletion through mid-September shown by MLS data is due to declining levels of chlorine coming from CFCs,” she added. “But we’re not yet seeing a clear decrease in the size of the ozone hole because that’s controlled mainly by temperature after mid-September, which varies a lot from year to year.”