Polar stratospheric clouds look lovely, glowing in streaks of spring Antarctic or Arctic sunrise. Yet the wispy wonders, around 20 kilometers up, are causing concern below. They create conditions that permit chlorine in the atmosphere to ravage the Earth’s protective ozone layer.
This week at the spring meeting of the American Geophysical Union in Washington, D.C., scientists announced that more polar stratospheric clouds formed in Arctic skies last winter than had ever been recorded previously and that the clouds lasted longer. Meanwhile, researchers say, they observed significant ozone loss.