Ozone Decline Stuns Scientists

Denver Post: Ozone Decline Stuns Scientists: "Solar flares and frigid temperatures are believed to be working with human chemicals to eat away at the protective ozone layer above the North Pole, surprising scientists who have been looking for evidence that the planet's ozone layer is healing.

The ozone layer protects Earth from dangerous ultraviolet radiation, which can cause skin cancer.

Last winter, Arctic ozone declined more precipitously than ever in the upper atmosphere, probably because of violent storms on the sun's surface, one team reports today in the journal Geophysical Research Letters.

And in recent days, a lower layer of ozone has undergone an extraordinary thinning because of a level of bitter cold (about minus-110 degrees Fahrenheit) rarely seen in the Arctic and manmade chemicals, researchers said. One Colorado scientist has raced north to document the event, expected to sputter out within days.

The two unusual findings have experts worried that they don't fully understand the dynamics of ozone depletion.

'I don't think we can be confident about whether or not we're seeing an ozone recovery or if we're attributing recovery to the correct causes,' said Cora Randall, an atmospheric scientist at the University of Colorado. [...]"