1995 Integrated Monitoring Study: Temporal variability of particulate matter - preliminary results
- California Air Resources Board, Sacramento, CA (United States)
- Desert Research Institute, Reno, NV (United States); and others
During the winter portion of the 1995 Integrated Monitoring Study (IMS95), 3-hour PM{sub 10} and PM{sub 2.5} sampling was conducted at four sites in the central and southern San Joaquin Valley. The objectives of the monitoring were to assess the diurnal variations in particulate matter (PM) concentrations and to provide information on the optimal averaging times to be used in future monitoring in the Valley. Data on PM{sub 10} and PM{sub 2.5} mass and composition (ions, OC/EC, and elements) were collected at Bakersfield, Fresno, Kern Wildlife Refuge, and Chowchilla from December 9, 1995 through January 6, 1996. Preliminary analysis of the mass data show that highest concentrations were observed at Fresno, with a maximum 24-hour PM{sub 10} concentration of 125 {mu}g/m{sup 3} and a maximum 24-hour PM{sub 2.5} concentration of 104 {mu}g/m{sup 3}. In general, PM{sub 2.5} comprised 70% to 80% of the PM10 mass. Significant variations in 3-hour PM concentrations were observed, with diurnal differences up to a factor of 10. Concentrations at the urban sites showed more diurnal variation, and tended to peak in the late evening, while concentration profiles at the rural sites were flatter, with maximum concentrations during the middle of the day. 4 refs., 15 figs., 4 tabs.
- OSTI ID:
- 617656
- Report Number(s):
- CONF-9605175--
- Country of Publication:
- United States
- Language:
- English
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