Or so were told. This seems a bit contradictory?
Scientists say an unprecedented ozone "hole" opened up above the Arctic last year, caused by an unusually prolonged period of extremely low temperatures
They found that at some altitudes, the cold period in the Arctic lasted more than 30 days longer in 2011 than in any previously studied Arctic winter, leading to the unprecedented ozone loss.
Or this? Brutal northern winter sees ozone hole open over the Arctic
Formed by a deep chill over the North Pole, the unprecedented hole at one point shifted over eastern Europe, Russia and Mongolia, exposing populations to higher, but unsustained, levels of ultraviolet light.How about "Northern Chill produces Artic Ozone" ?
But the loss itself is driven by deep cold, which causes water vapour and molecules of nitric acid to condense into clouds in the lower stratosphere.
However, this year Arctic temperatures in the lower stratosphere were continuously cold from December until April, says Santee.
"This year in the Arctic temperatures did get cold, but more importantly they stayed cold for a really, really long time."
The Artic got cold and it stayed really cold. Curious?