Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Comparison of Particle Light Scattering and Fine Particulate Matter Mass in Central California
Particle light scattering (Bsp) from nephelometers and fine particulate matter (PM2.5) mass determined by filter samplers are compared for summer and winter at 35 locations in and around California’s San Joaquin Valley from December 2, 1999 to February 3, 2001. The relationship is described using particle mass scattering efficiency (σsp) derived from linear regression of Bsp on PM2.5 that can be applied to estimated PM2.5 from nephelometer data within the 24-hr filter sampling periods and between the every-6th-day sampling frequency. An average of σsp =4.9 m2/g was found for all of the sites and seasons; however, σsp averaged by site type and season provided better PM2.5 estimates. On average, the σsp was lower in summer than winter, consistent with lower relative humidities, lower fractions of hygroscopic ammonium nitrate, and higher contributions from fugitive dust. Winter average σsp were similar at non-source-dominated sites, ranging from 4.8 m2/g to 5.9 m2/g. The σsp was 2.3 m2/g at the roadside, 3.7 m2/g at a dairy farm, and 4.1 m2/g in the Kern County oilfields. Comparison of Bsp from nephelometers with and without a PM2.5 inlet at the Fresno Super-site showed that coarse particles contributed minor amounts to light scattering. This was confirmed by poorer correlations between Bsp and coarse particulate matter measured during a fall sampling period.
Comparison of Particle Light Scattering and Fine Particulate Matter Mass in Central California
Particle light scattering (Bsp) from nephelometers and fine particulate matter (PM2.5) mass determined by filter samplers are compared for summer and winter at 35 locations in and around California’s San Joaquin Valley from December 2, 1999 to February 3, 2001. The relationship is described using particle mass scattering efficiency (σsp) derived from linear regression of Bsp on PM2.5 that can be applied to estimated PM2.5 from nephelometer data within the 24-hr filter sampling periods and between the every-6th-day sampling frequency. An average of σsp =4.9 m2/g was found for all of the sites and seasons; however, σsp averaged by site type and season provided better PM2.5 estimates. On average, the σsp was lower in summer than winter, consistent with lower relative humidities, lower fractions of hygroscopic ammonium nitrate, and higher contributions from fugitive dust. Winter average σsp were similar at non-source-dominated sites, ranging from 4.8 m2/g to 5.9 m2/g. The σsp was 2.3 m2/g at the roadside, 3.7 m2/g at a dairy farm, and 4.1 m2/g in the Kern County oilfields. Comparison of Bsp from nephelometers with and without a PM2.5 inlet at the Fresno Super-site showed that coarse particles contributed minor amounts to light scattering. This was confirmed by poorer correlations between Bsp and coarse particulate matter measured during a fall sampling period.
Comparison of Particle Light Scattering and Fine Particulate Matter Mass in Central California
Chow, Judith C. (Autor:in) / Watson, John G. (Autor:in) / Park, Kihong (Autor:in) / Robinson, Norman F. (Autor:in) / Lowenthal, Douglas H. (Autor:in) / Magliano, Karen A. (Autor:in)
Journal of the Air & Waste Management Association ; 56 ; 398-410
01.04.2006
13 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Unbekannt
Comparison of Particle Light Scattering and Fine Particulate Matter Mass in Central California
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