August 2003 Blackout Cleared The Air
Skies were bluer and the air was healthier over much of the eastern United States during the blackout that hit the northeast and southeastern Canada last August, researchers at the University of Maryland report.
Atmospheric measurements taken by the scientists on August 15, 24 hours after many power plants had shut down, found a 90 percent reduction in sulfur dioxide, a gas that leads to haze and acid rain, and a 50 percent reduction in smog, or ground-level ozone.
The amount of light scattering particles in the air dropped by 70 percent and visibility increased by some 20 miles.
Researchers Lackson Marufu, Bryan Bloomer, Charles Piety, Bruce Doddridge, Jeffrey Stehr, and Russell Dickerson of the Meteorology Department and Brett Taubman of the Chemistry Department reported their findings in “The 2003 North American Electrical Blackout: An Accidental Experiment in Atmospheric Chemistry,” which will be published in the next issue of “Geophysical Research Letters.”
Dickerson, professor and chair of the Meteorology Department, said, “Scientists long have speculated about what would happen to air quality if all the power plants suddenly disappeared. The blackout performed for us an experiment that would have otherwise been impossible. The resulting clean air that we observed over large areas of rural Pennsylvania was headed toward the Mid-Atlantic, so cities from Washington to New York reaped the benefits of bluer skies, at least for a few days.”
“What surprised us was not so much the observation of improved air quality during the blackout, but the magnitude of the observed improvement,” says Marufu. “The improvement in air quality was so great that you could not only measure it, but could actually see it as a much clearer less hazy sky.”
Fossil fuel fired power plants account for more than half of electrical energy production in the United States, and for about 22 percent of the nitrogen oxides and about 69 percent of the sulfur dioxide emissions, the scientists said.
In summertime, under a high pressure front, westerly winds carry power plant emissions from Ohio, West Virginia and Pennsylvania to form severe smog and haze in the northeastern U.S. composed of ground-level ozone, or smog, and sulfate-dominated fine particles.
Both pollutants have been linked to adverse health effects, degradation of the environment, and global climate change.
Provided by the Environmental News Service.
