Ozone trends in California`s South Coast Air Basin, 1976--1996
- South Coast Air Quality Management District, Diamond Bar, CA (United States)
The South Coast Air Basin (Basin) of Southern California exhibits the worst air quality in the nation, as measured by the annual number of days exceeding the 1-hour National Ambient Air Quality Standard (NAAQS) for ozone. Hourly pollutant concentration data collected by the South Coast Air Quality Management District`s air monitoring network are compared to the existing 1-hour and new 8-hour federal ozone ambient air quality standards to depict ozone trends and compliance in the Basin. Results of trend analyses for the different areas of the Basin are presented for the 1-hour and 8-hour standards, and the relative stringency of the existing and new federal standards is examined. Based on an analysis of the effect of the recently adopted federal standard on ozone compliance in the Basin, ozone concentrations exceed the new federal 8-hour standard level more often than the existing 1-hour standard in most locations. However, examination of the trends in design values for the 1-hour and 8-hour ozone standards suggests that for most locations in the Basin the new standard probably should not be significantly more difficult to attain than the existing standard. The weather-adjusted ozone trend analysis in the Basin confirms the fact that the downtrends in ozone concentrations and number of days exceeding standards are real and independent of annual variation in weather. An analysis of weekday/weekend differences in exceedances for the existing 1-hour and new 8-hour ozone standards show a higher number of days exceeding both standards on weekends for most locations in the Basin, with differences being more evident in the 1990s than in the late 1970s and 1980s
- OSTI ID:
- 362004
- Report Number(s):
- CONF-980632-; TRN: IM9933%%388
- Resource Relation:
- Conference: 91. annual meeting and exhibition of the Air and Waste Management Association, San Diego, CA (United States), 14-18 Jun 1998; Other Information: PBD: 1998; Related Information: Is Part Of Proceedings of the 91. annual meeting and exhibition. Bridging international boundaries: Clean production for environmental stewardship; PB: [5000] p.
- Country of Publication:
- United States
- Language:
- English
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