Ozone hole has shrunk and split, say scientists

The ozone hole over Antarctica is markedly smaller this year than in the past few years and has split in two, US government scientists reported.

The so-called “hole”, actually an area thinner than normal ozone, was measured at 15.6 million square kilometres in September. It was 23.4 million square kilometres in September of the past six years, researchers at the US National Oceanic and Atmospheric Administration and NASA said.

While ozone at ground level is considered a pollutant, the layer of ozone in the stratosphere is vital to life because it blocks dangerous radiation coming from the sun.

Thinning of the ozone layer could lead to a rise in skin cancer, experts warn.

Aerosols and other chemicals are blamed for the thinning, and treaties banning those ingredients are expected to help the layer recover.

This year’s improvement was attributed to warmer than normal temperatures around the edge of the polar vortex, or a circular wind pattern that forms annually in the stratosphere over Antarctica.

The stratosphere over the southern hemisphere was unusually disturbed this year by the wind, causing the hole to split into two separate holes.