Research Projects

Project at a Glance

Project Status: complete

Report Published May 1980:

Title: Methods for sulfate air quality management. Volume 1: Executive summary, Volume 2: Main text, Volume 3: Appendices

Principal Investigator / Author(s): Cass, Glen R

Contractor: California Institute of Technology

Contract Number: A6-061-87

Research Program Area: Emissions Monitoring & Control, Atmospheric Processes

Topic Areas: Area Sources, Modeling


A study of methods for sulfate air quality control strategy design has been conducted. Analytical tools developed were tested within a case study of the nature and causes of the high sulfate concentrations observed in the Los Angeles area. A principal objective was to investigate the least costly means for sulfate air quality improvement in that locale. A long-run average emissions to air quality model was derived which computes pollutant concentrations from Lagrangian marked particle statistics based on the time sequence of measured wind speed, wind direction, and inversion base motion. Physical assumptions drawn from analysis of existing air quality and meteorological data were used to adapt this model to a specific application- sulfate air quality prediction in Los Angeles. An energy and sulfur balance on the fate of energy resources containing sulfur was developed to test the consistency of a sulfur oxides emissions inventory for that air basin. Then material balance arguments were used to trace sulfur flows within that regional energy economy through the air quality model which also conserves sulfur mass. Sulfate air quality model predictions were compared to historical observations over the years 1972 through 1974. The sulfate air quality impact of individual emission source classes was estimated at a large number of air monitoring sites. A hybrid theoretical-empirical model was constructed which explains the relationship between sulfate air quality and prevailing visibility at Los Angeles. An estimate was made of the visibility improvement which would have occurred if Los Angeles sulfate concentrations were reduced by 50 percent on each past day of record. Then two emissions control strategy example calculations were performed to illustrate the means by which the air quality model results could be used to evaluate the cost of attaining such an air quality improvement.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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