A NASA-led study found an unprecedented level of depletion of the ozone layer above the arctic last winter and spring, according to a story on NASA's website.
According to the study, which was published Sunday in the journal Nature, the level of ozone depletion is comparable to that of the ozone "hole" that forms in Antarctica each year. The ozone layer, which is about 10 to 20 miles above the earth's surface, protects the planet from the sun's ultraviolet rays.
Scientists said the depletion was caused to a prolonged period of extremely low temperatures in the stratosphere.
Read the NASA story HERE.