OZONE-An Augmented Hope

NASA states that the ozone layer protects the earth’s surface from the harmful rays of the sun that may cause cancer and cataracts in human beings, and may even damage plant life. A massive hole was identified in the ozone layer by the researchers in the mid-80s caused primarily due to chemicals such as chlorofluorocarbons (CFCs). The satellite observations then made revealed changes in the size of the ozone hole, signifying it to shrink every year.

However, according to a recent study published on Jan, 4 in the journal Geophysical Research Letters, it is time to pay off the efforts taken to heal the hole in earth’s ozone layer over Antarctica. This, first-of-its-kind study emphasized at the ozone-destroying chemicals in the atmosphere rather the size. The new study measured changes in the amount of chlorine between 2005 and 2016 by the Microwave Limb Sounder (MLS). This detects hydrochloric acid, formed when chlorine atoms react with methane and then bond with hydrogen, instead of directly detecting the chlorine atoms.

It has been observed that during summer, when the sun’s rays fall all over Antarctica’s southern hemisphere, the CFCs break down and produce chlorine, breaking apart the ozone atoms. However, according to a statement, the chlorine, during the winter months, binds with methane “once all the ozone has been destroyed” in its vicinity. Lead study author at NASA’s Goddard Space Flight Center, Susan Strahan said, “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.”

A daily observation at the ozone hole during the winter revealed a decreased ozone depletion, directly proportional to a decrease in the presence of chlorine from the CFCs. Susan states, “The 20-percent reduction in depletion is very close to what our model predicts we should see for this amount of chlorine decline. 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.”