Size and composition distribution of atmospheric particles in southern California

Journal Article · Fri Oct 15 04:00:00 EDT 1999 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es980884a· OSTI ID:20000726

Hughes, L S; Allen, J O; Kleeman, M J ^[1]

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1. and others

Continuous measurements of single particle size and chemical composition in the atmosphere are made using aerosol time-of-flight mass spectrometers (ATOFMS) operated alongside more conventional reference air sampling instruments at a network of three urban air monitoring sites in southern California. Electrical aerosol analyzers and optical particle counters are employed to acquire continuous particle size distribution data, and inertial impactor and bulk filter samples with 4-h resolution are taken for determination of particle size and chemical composition. Filter and impactor samples also are taken upwind of the air basin at Santa Catalina Island in order to characterize background air quality. The airborne particle size and composition distribution as measured by the cascade impactors at inland sites differ from that over the ocean principally due to depletion of sea salt particles accompanied by the addition of fine carbon-containing particles and secondary aerosol nitrate. Data from the ATOFMS systems create a continuous time series of sodium-, ammonium-, nitrate-, and carbon-containing particle counts that provide a high-resolution view of differences in particle composition as a function of location in the air basin. Results show that the characteristic peak in the Los Angeles area aerosol mass distribution in the 0.2--0.3-{micro}m size range observed during the 1987 SCAQS experiments has been reduced, consistent with reductions in diesel soot and elemental carbon emissions since that time.

• Research Organization: California Inst. of Tech., Pasadena, (US)
• OSTI ID: 20000726
• Journal Information: Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 20 Vol. 33; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
AIR POLLUTION MONITORING
CALIFORNIA
CHEMICAL COMPOSITION
PARTICLE SIZE
PARTICULATES