2014 Ozone Hole Over Antarctica Reached Its Largest in September

It turns out that the ozone hole over the Antarctic is persisting through this Halloween. The hole reached its annual peak size on Sept. 11, holding at 9.3 million square miles, an area roughly the size of North America.

That's not to say that this is the largest that the ozone hole has ever been. That title belongs to the ozone hole that appeared on Sept. 9, 2000. At the time, the hole was measured at 11.5 million square miles. The 2014 hole, in contrast, was smaller than the large holes of the 1998 to 2006 period and is comparable to 2010, 2012 and 2013.

"Year-to-year weather variability significantly impacts Antarctica ozone because warmer stratospheric temperatures can reduce ozone depletion," said Paul Newman, chief scientist for atmospheres at NASA's Goddard Space Flight Center, in a news release. "The ozone hole area is smaller than what we saw in the late-1990s and early 200s, and we know that chlorine levels are decreasing. However, we are still uncertain about whether a long-term Antarctic stratospheric temperature warming might be reducing this ozone depletion."

Currently, scientists are working to see if the ozone hole trend is due to temperature increases or chlorine declines. This could tell them whether stricter regulations need to be put in place in order to curtail emissions or not.

The findings reveal that the ozone hole does indeed seem to be shrinking over time. The ozone hole will continue to slowly shrink until it begins to grow again as the seasons change.