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

Brett F. Taubman
Department of Chemistry, University of Maryland, College Park, Maryland, USA

Bryan Bloomer
Department of Meteorology, University of Maryland, College Park, Maryland, USA

Charles A. Piety
Department of Meteorology, University of Maryland, College Park, Maryland, USA

Bruce G. Doddridge
Department of Meteorology, University of Maryland, College Park, Maryland, USA

Jeffrey W. Stehr
Department of Meteorology, University of Maryland, College Park, Maryland, USA

Russell R. Dickerson
Department of Meteorology, University of Maryland, College Park, Maryland, USA

Abstract

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.

Citation: Marufu, L. T., B. F. Taubman, B. Bloomer, C. A. Piety, B. G. Doddridge, J. W. Stehr, and R. R. Dickerson (2004), The 2003 North American electrical blackout: An accidental experiment in atmospheric chemistry, Geophys. Res. Lett., 31, L13106, doi:10.1029/2004GL019771.