NASA says that the ozone hole in the atmosphere was the smallest in 2018 and 2019 that is has been since it was first observed in 1982. The annual ozone hole reached its peak extent of 6.3 million square miles on September 8 and then shrank to less than 3.9 million square miles for the remainder of September and October, according to NASA.
NASA says that during years with normal weather conditions, the ozone hole typically grows to a maximum area of about 8 million square miles in late September or early October. NASA chief scientist for Earth Sciences, Paul Newman, says that the reason from the smaller ozone hole this year is due to warmer temperatures in the stratosphere.
Newman specifically says that this isn’t a sign that atmospheric ozone is suddenly on the fast track to recovery. Ozone is a molecule that occurs naturally in small amounts that is comprised of three oxygen atoms. Ozone usually resides in the stratosphere about seven to 25 miles above the surface of the Earth.
Ozone in the atmosphere acts as a sunscreen and shields the planet from harmful ultraviolet rays that can cause skin cancer and cataracts. NASA says that warmer temperatures mean fewer stratospheric clouds form, and they don’t persist as long, and the ozone depletion process is limited. Scientists also noted that balloons carrying ozone-measuring “sondes” that directly sample ozone levels in the atmosphere didn’t show any portions of the atmosphere where ozone was completely depleted.
Scientists say that this is the third time in the last 40 years that weather systems have cause warm temperatures that limited ozone depletion. Scientist Susan Strahan says that if the warming hadn’t happened, we’d likely have a more typical ozone hole. The team notes that there is no identified connection between unique patterns and climate change.