For now, the Arctic is a wonderland of snow and ice, blessed always with a white Christmas. But come spring, when the sun inches above the horizon for the first time in months, chemical chaos will reign. When sunlight hits the glittering drifts, it unleashes a sequence of chemical reactions that would make the Grinch shudder. Ozone, a pollutant hovering in the air above the snow, gets destroyed.
Toxic mercury becomes concentrated in the snowpack.
Reactive nitrogen and organic compounds waft into the air. Scientists are just beginning to understand the complex dance of chemicals between snow and air, and how pollution and other human problems might affect that delicate balance. The new results, reported recently at a San Francisco meeting of the American Geophysical Union, could help researchers pinpoint ways to keep faraway polluters from harming the fragile Arctic environment. The ozone loss, mercury concentration and other chemical processes occur naturally, he noted. But people might be speeding them up by adding atmospheric pollutants, which spread into even the most pristine-seeming regions of the Arctic.