GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L13106, doi:10.1029/2004GL019771, 2004
The 2003 North American electrical blackout: An accidental experiment in atmospheric chemistry
Lackson T. Marufu
Department of Meteorology, University of Maryland, College Park, Maryland, USA
The August 2003 North American electrical blackout provided a unique opportunity to quantify directly the contribution of power plants to regional haze and O3. Airborne observations over central Pennsylvania on August 15, 2003, ∼24 h into the blackout, revealed large reductions in SO2 (>90%), O3 (∼50%), and light scattered by particles (∼70%) relative to measurements outside the blackout region and over the same location when power plants were operating normally. CO and light absorbing particles were unaffected. Low level O3 decreased by ∼38 ppbv and the visual range increased by >40 km. This clean air benefit was realized over much of the eastern U.S. Reported SO2 and NOx emissions from upwind power plants were down to 34 and 20% of normal, respectively. The improvement in air quality provides evidence that transported emissions from power plants hundreds of km upwind play a dominant role in regional haze and O3 production.
Received 19 February 2004; accepted 8 June 2004; published 15 July 2004.
Index Terms: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0315 Atmospheric Composition and Structure: Biosphere/atmosphere interactions; 0368 Atmospheric Composition and Structure: Troposphere—constituent transport and chemistry; 3307 Meteorology and Atmospheric Dynamics: Boundary layer processes; 6620 Public Issues: Science policy.
The 2003 North American electrical blackout: An
accidental experiment in atmospheric chemistry, Geophys. Res. Lett.,