Depletion could expose midlatitudes to higher-than-normal UV
The annual thinning of ozone over the Arctic is shaping up to be especially severe this spring, measurements by European scientists indicate. During the past six weeks, a large portion of the region’s stratosphere has lost at least half of the layer that normally filters out much of the sun’s harmful ultraviolet rays.
The new data “are kind of a warning that we might be getting into an ozone hole situation,” says Francis Schmidlin of NASA’s Wallops Flight Facility in Virginia, whose team is not affiliated with the European polar-ozone monitoring group.
Data radioed back from sensors aboard high-altitude weather balloons show the ozone-depleted region spans about 15 million square kilometers — an area about 22 times the size of Texas. Although the affected parcel of air 20 kilometers above Earth’s surface tends to remain roughly centered over the North Pole, it can wander as far south as Italy or Greece for a few days at a tim