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AGU: Journal of Geophysical Research, Atmospheres

 

Keywords

  • Fresno Supersite
  • PM2.5
  • ammonium nitrate
  • organic matter
  • spatial distribution

Index Terms

  • Atmospheric Composition and Structure: Middle atmosphere: composition and chemistry
  • Atmospheric Composition and Structure: Middle atmosphere: constituent transport and chemistry
  • Atmospheric Composition and Structure: Pollution: urban and regional
  • Atmospheric Processes: Synoptic-scale meteorology
Abstract
Cited By (23)
 

Abstract

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, D10S04, 17 PP., 2006
doi:10.1029/2005JD006457

PM2.5 chemical composition and spatiotemporal variability during the California Regional PM10/PM2.5 Air Quality Study (CRPAQS)

Judith C. Chow

Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada, USA

L.-W. Antony Chen

Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada, USA

John G. Watson

Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada, USA

Douglas H. Lowenthal

Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada, USA

Karen A. Magliano

California Air Resources Board, Sacramento, California, USA

Kasia Turkiewicz

California Air Resources Board, Sacramento, California, USA

Donald E. Lehrman

Technical and Business Systems, Santa Rosa, California, USA

The 14-month-long (December 1999 to February 2001) Central California Regional PM10/PM2.5 Air Quality Study (CRPAQS) consisted of acquiring speciated PM2.5 measurements at 38 sites representing urban, rural, and boundary environments in the San Joaquin Valley air basin. The study's goal was to understand the development of widespread pollution episodes by examining the spatial variability of PM2.5, ammonium nitrate (NH4NO3), and carbonaceous material on annual, seasonal, and episodic timescales. It was found that PM2.5 and NH4NO3 concentrations decrease rapidly as altitude increases, confirming that topography influences the ventilation and transport of pollutants. High PM2.5 levels from November 2000 to January 2001 contributed to 50–75% of annual average concentrations. Contributions from organic matter differed substantially between urban and rural areas. Winter meteorology and intensive residential wood combustion are likely key factors for the winter-nonwinter and urban-rural contrasts that were observed. Short-duration measurements during the intensive operating periods confirm the role of upper air currents on valley-wide transport of NH4NO3. Zones of representation for PM2.5 varied from 5 to 10 km for the urban Fresno and Bakersfield sites, and increased to 15–20 km for the boundary and rural sites. Secondary NH4NO3 occurred region-wide during winter, spreading over a much wider geographical zone than carbonaceous aerosol.

Received 1 July 2005; accepted 4 January 2006; published 25 May 2006.

Citation: Chow, J. C., L.-W. A. Chen, J. G. Watson, D. H. Lowenthal, K. A. Magliano, K. Turkiewicz, and D. E. Lehrman (2006), PM2.5 chemical composition and spatiotemporal variability during the California Regional PM10/PM2.5 Air Quality Study (CRPAQS), J. Geophys. Res., 111, D10S04, doi:10.1029/2005JD006457.

Cited By

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