Research Projects

Project at a Glance

Project Status: complete

Title: Chemistry, dispersion, and transport of air pollutants emitted from fossil fuel power plants in California: airborne pollutant measurement and analysis.

Principal Investigator / Author(s): Smith, T. B.

Contractor: Meteorology Research, Inc.

Contract Number: 3-929

Research Program Area: Atmospheric Processes

Topic Areas: Transport


An extensive field program has been carried out to investigate the effect of large, fossil fuel plants on the air quality environment in California. Primary objectives of the program included an evaluation of the impact of the plants on surface SO2 and NOx concentrations and an assessment of the importance of SO2 and NOx reactions in the plume. A number of organizations cooperated in the field studies. These included Caltech, Rockwell Air Monitoring Center, Environmental Measurements, Inc. and Meteorology Research, Inc. The program consisted of SF6 tracer releases from three different power plants and downwind sampling of SO2 , SF6 , and sulfates on the ground and in an instrumented aircraft. NOx and other pollutants were also sampled in the aircraft.

The MRI portion of the studies consisted of airborne and meteorological measurements. Analyses of the data include an estimate of the impact of the plume on surface concentrations, details of the plume behavior and reaction estimates within the plume. With only one major exception the plumes from the plant were confined to the low level mixing layer and impacted at ground levels from 13 to 24 km downwind of the plant. On one day (September 10) at Moss Landing the plume penetrated above the mixing layer and did not significantly affect ground level concentrations. Peak hourly ground concentrations were found from the tracer studies to range between 0.009 and 0.082 ppm of equivalent SO2 for a given power plant on the sampling days. An unusual feature of the Haynes-alamitos studies was the consistency of the plume direction from the plants. On all test days the plume direction during the early afternoon hours (when mixing to the ground occurs most readily) was toward the northeast. Thus the area affected by the plumes from Haynes-Alamitor tends to be consistent and rather localized under typical seabreeze conditions.

The reaction of NO, NO2 and O3 in the plumes occurred rapidly and resulted in ozone deficits in the plumes. The conversion of SO2 to sulfate occurred too slowly to be detected within the downwind distance of the identifiable plumes.

This report was submitted by MRI in fulfillment of Contract No. ARB 3-929 under sponsorship of the California Air Resources Board. Work was completed as of November 30, 1975.


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

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