Record low ozone levels observed over Arctic

Abstract

Stratospheric ozone levels in the Arctic region have been as much as 40% lower than normal this European scientists report. This drop—although not as steep—looks uncomfortably like the dramatic losses seen in the recurring ozone hole over Antarctica. It's very clear there has been extremely low ozone within the Arctic vortex this past winter, says John Pyle, coordinator of the Second European Stratospheric Arctic & Mid-Latitude Experiment (SESAME), which has announced these observations. In certain thin layers, we've seen 50% depletion from the long-term norm. SESAME probes the stratosphere with aircraft, balloons, and ground-based instruments. Extremely low ozone levels in the northernmost latitudes also have been recorded by a network of ground-based ozone-monitoring instruments coordinated by the World Meteorological Organization (WMO). For eight, nine weeks in a row we have seen ozone down at least 20 to 25%, Rumen D. Bojkov, special adviser to the WMO secretary general, tells C&EN. The...