We've been hearing about the hole in the ozone layer over Antarctica since the 80s. This thinning out of Earth's important ozone layer is what resulted in many aerosols being reformulated to help reduce the rate that ozone is being depleted. Scientists report that satellite data has now revealed a slight shrinking of the ozone hole this year.
The Antarctic ozone hole is described as a seasonal phenomenon that starts during August and satellite data shows it was smaller this year on average that over the past several decades. Data reveals the average size of the ozone hole between September and October of 2013 was 8.1 million square miles. NASA revealed this data late last week.
By comparison, the average size of the ozone hole since the mid-1990s was 8.7 million square miles. Scientists are quick to point out that a single year change isn't enough data to determine if the ozone hole phenomenon has started to heal.
NASA's data was supplied by instruments aboard the Aura satellite as well as the Ozone Monitoring and Profiler Suite instrument aboard the NASA-NOAA Suomi National Over-orbiting Partnership satellite. The ozone hole begins to form each year during the Antarctic spring when the sun begins to rise after months of winter darkness. Cold air trapped above the continent by polar-circling winds and sunlight acts as a catalyst for a reaction involving ice clouds and chlorine from man-made chemicals. That reaction causes depletion the ozone layer until early December.
The single-day maximum area this year was reached on Sept. 16 when the maximum area reached 9.3 million square miles (24 million square kilometers), about equal to the size of North America. The largest single-day ozone hole since the mid-1990s was 11.5 million square miles (29.9 million square kilometers) on Sept. 9, 2000.