By Sid Perkins
After the long, dark polar winter, the sun returns to shine on the high-latitude snows. Simultaneously, the concentration of ozone at low altitudes begins to drop. In research conducted on the Arctic snowpack last spring, scientists used sunlamps to illuminate some of the chemistry of this phenomenon.
The experiment showed that pollutants trapped in Arctic snow, when energized by sunlight, can escape the snowpack and deplete ozone in the lower atmosphere, says Jan W. Bottenheim, a senior scientist at the Meteorological Service of Canada in Toronto, Ontario.