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Dimensions of the Los Angeles SO_2/sulfate problem

Cass, Glen R. (1975) Dimensions of the Los Angeles SO_2/sulfate problem. Environmental Quality Laboratory Memorandum, 15. California Institute of Technology , Pasadena, CA. (Unpublished)

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Sulfur dioxide emission trends are reviewed in relation to sulfur dioxide air quality in the Los Angeles area. Emission fluctuations over the 19-year period from 1956 through 1974 are explained in terms of emission control policy changes. Simple statistical tests indicate that measured SO_2 air quality levels at Long Beach and downtown Los Angeles track changes in emission strength at nearby sources and from sources with low effective stack height. Atmospheric oxidation of SO_2 to form particulate sulfates is discussed. Sulfate air quality measurements at Los Angeles show a broad summer seasonal peak in all years of record, with isolated periods of very high sulfate concentration in some winters of record. The geographic distribution of long term average sulfate concentrations is examined and found to be rather uniform across existing monitoring stations in the Los Angeles Basin. Fluctuations in measured sulfate values from day to day are shown to track changes in inversion height, relative humidity, total suspended particulate levels, and ozone concentrations. From these relationships, it is suggested that day-to-day fluctuations in sulfate concentration are driven mainly by changes in SO_2 to sulfate reaction rate and by changes in the effective mixing volume of the air basin.

Item Type:Report or Paper (Technical Report)
Additional Information:© 1975 Environmental Quality Laboratory. California Institute of Technology. This work has been supported by the Ford Foundation (Grant No. 740-0469), a grant to the author from Rockwell International, and gifts to the Environmental Quality Laboratory. The author wishes to thank Anna Pechanec and Betsy Krieg for research assistance on this project. Thanks is also due to the staff of the Los Angeles Air Pollution Control District for cooperation and assistance in furnishing data for this analysis. Valuable advice on data handling procedures was furnished by Dr. R. C. Y. Koh. NOTE TO CONFERENCE PARTICIPANTS: This is a condensed version of materials presented at the Conference on Strategies for Air Pollution Control in the South Coast Air Basin, December 2-3, 1975. Remarks presented at that meeting concerning the automotive aspects of Los Angeles sulfate air quality are published separately as "Lead as a Tracer for Automotive Particulates: Projecting the Sulfate Air Quality Impact of Oxidation Catalyst Equipped Cars in Los Angeles," Environmental Quality Laboratory Memorandum No. 12.
Group:Environmental Quality Laboratory
Funding AgencyGrant Number
Ford Foundation740-0469
Rockwell InternationalUNSPECIFIED
Environmental Quality LaboratoryUNSPECIFIED
Series Name:Environmental Quality Laboratory Memorandum
Issue or Number:15
Record Number:CaltechEQL:EQL-M-15
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Usage Policy:You are granted permission for individual, educational, research and non-commercial reproduction, distribution, display and performance of this work in any format.
ID Code:25764
Deposited By: Imported from CaltechEQL
Deposited On:08 Dec 2009
Last Modified:03 Oct 2019 03:08

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