A big hole in the ozone layer has opened over the arctic

In March weather balloons over the arctic reported a 90 percent drop in ozone near the center of the ozone layer.

Usually the ozone at this altitude is 3.5 parts per million but this time it was around .3 parts per million. “That beats any ozone loss we have observed in the past,” said Markus Rex, an atmospheric scientist at Alfred Wegner Institute in Potsdam.

Although the arctic saw a loss of ozone in 2011 and 1997, scientists say this might be the largest loss on record. The journal Nature called it “an extraordinary atmospheric event that will go down in the record books.”

“We have at least as much loss as in 2011, and there are some indications that it might be more than 2011,” Gloria Manney, an atmospheric scientist at Northwest Research Associates in Socorro, New Mexico, told Nature.. 

Ozone shields life on planet earth from dangerous solar radiation. When polluted clouds that contain chemicals such as bromine and chlorine form over the arctic, chemical reactions take place on the cloud surfaces and destroy ozone. A polar vortex trapped cold air over the artic facilitating the extremely cold temperatures which are necessary for the high-altitude clouds to form.

The hole is expected to heal in the coming weeks and hopefully will not reoccur in subsequent years due to the passing of an international treaty that phases out the use of ozone-depleting chemicals. Rex said that there’s not a health threat because the sun will soon warm higher latitudes melting the polluted clouds. If the hole did drift to populated areas people would just need to be careful to apply sunscreen.

“Right now, we’re just eagerly watching what happens,” said Ross Salawitch, an atmospheric scientist at the University of Maryland in College Park. “The game is not totally over.”