for National Geographic News
Winter winds circling high above the North Pole drew down near-record amounts of ozone-destroying gases from the upper atmosphere last year, according to a new study.
The destruction of this ozone, which heats the upper atmosphere, could have profound impacts on global climate.
What's more, some climate models suggest that global warming will increase the average strength of polar winds.
Scientists had long believed that highly reactive nitrogen-oxygen gases, collectively referred to as NOx, were drawn down only when large quantities were formed during intense solar storms.
But last winter, when solar activity was low, strong circumpolar winds over the Arctic produced a major downflux of the gases.
More frequent strong winds would bring down more gases and further deplete the ozone layer, which would in turn affect climate change.
Still, says study author Cora Randall, an atmospheric scientist at the University of Colorado at Boulder, other climate models show that global warming will cause polar winds to decrease.
"There are still a lot of questions," she said.
Ozone serves two major roles in the middle part of the atmosphere known as the stratosphere.
At lower elevations, the molecules block ultraviolet (UV) light, reducing the amount of the skin-cancer-causing rays that reach the ground.
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