Project at a Glance
Title: Air quality in the South Coast Air Basin: trends, modeling database, areal distribution.
Principal Investigator / Author(s): South Coast Air Quality Management District
Contract Number: A6-164-70
Research Program Area: Atmospheric Processes
Topic Areas: Modeling
This report is the second in a series of work plan documents prepared to develop strategies "to protect and enhance the quality of the nation's air resources so as to promote the public heath and welfare and the productive capacity of its population."
The first document in this series described the Air Quality Management Plan (AQMP) "Goals and Policies" and the "Aerometric Data." This second document will present air contaminant data for monitoring sites in the South Coast Air Basin in sufficient detail to define the air quality improvement needed to attain the air quality standards. To provide reader orientation, Tables I-I and I-II originally included in the "Goals and Policies" document are also included here. Table I (two pages) lists the various state and federal air quality standards and emergency criteria. Table I-II list the "Class A" stations in the SCAQMD air monitoring network, which provide the bulk of data which follows.
Numerous graphs, maps, charts, tables, and texts which delineate the geographic, seasonal, and diurnal distribution of various air quality parameters for the base period 1972-1976 are presented and briefly discussed in Sections III and IV. Section V presents examples of trends and projections for oxidant, carbon monoxide, and nitrogen dioxide obtained by treating the data to normalize the apparent trend for meteorological factors, or by treatment using standard statistical methods. These are exploratory methods of data treatment, not definitive at present, and clearly indicate that the method of data analysis will affect the conclusions drawn as to long- or short-term trends.
Section VI describes the aerometric database to be used in the Stage II modeling process, and also the population exposure to the various contaminants for the different time-averaging periods.
Since this is a work plan document, and the output of the modeling process may ultimately define the dates of attainment of the standards and for the quantification of emission reductions required to achieve this goal, conclusions based on the untreated data are preliminary, and will require more intensive study.
For questions regarding research reports, contact: Heather Choi at (916) 322-3893
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