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Acquisition of regional air quality model validation data for nitrate, sulfate, ammonium ion and their precursors

Russell, Armistead G. and Cass, Glen R. (1984) Acquisition of regional air quality model validation data for nitrate, sulfate, ammonium ion and their precursors. Atmospheric Environment Part A-General Topics, 18 (9). pp. 1815-1827. ISSN 0960-1686. doi:10.1016/0004-6981(84)90357-3.

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An intensive field study was conducted throughout California's South Coast Air Basin to acquire air quality model validation data for use with aerosol nitrate formation models. Aerosol nitrate, sulfate, ammonium, other major ionic aerosol species, nitric acid gas and ammonia were measured concurrently at ten sites for forty-eight consecutive hours during the period 30–31 August 1982. Ozone, NO and NO_x were measured at all locations, and PAN was measured at Pasadena and Riverside, completing a nitrogen balance on the air masses studied. The product of the measured nitric acid and ammonia concentrations ranged from less than 1 ppbv^2 to greater than 300 ppbv^2 during the experiment, providing a wide range of conditions over which comparisons can be drawn between chemical equilibrium calculations and experimental results. The ionic material in the aerosol phase was chemically more complex than is assumed by present theoretical models for the equilibrium between NH_3, HNO_3 and the aerosol phase, and included significant amounts of Na^+, Ca^(2+), Mg^(2+), K^+ and Cl^− in addition to NH_4^+, SO_4^(2−) and NO_3^−. Results of the experiment showed that aerosol nitrate levels in excess of 20 μm^(−3) accumulated in near-coastal locations in the morning of 31 August, followed by subsequent transport across the air basin. Trajectory analysis showed that the afternoon aerosol nitrate peak observed inland at Rubidoux near Riverside was associated with the same air mass that contained the high morning nitrate levels near the coast, indicating that description of both transport and atmospheric chemical reactions is important in understanding regional nitrate dynamics.

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Additional Information:© 1984 Pergamon Press Ltd. This study was supported by the California Air Resources Board under Agreement No. A2-150-32 and by gifts to the Environmental Quality Laboratory. The South Coast Air Quality Management District and the California Air Resources Board cooperated by allowing access to their air monitoring sites, and provided meteorological and gaseous pollutant data. Special thanks also goes to Dennis Fitz and the Statewide Air Pollution Research Center at the University of California at Riverside whose services were greatly appreciated. We would also like to thank the Caltech students and staff who helped to operate each of the pollutant sampling sites.
Group:Environmental Quality Laboratory
Funding AgencyGrant Number
California Air Resources BoardA2-150-32
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Other Numbering System NameOther Numbering System ID
Environmental Quality LaboratoryA-163
Issue or Number:9
Record Number:CaltechAUTHORS:20140923-084618526
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Official Citation:Armistead G. Russell, Glen R. Cass, Acquisition of regional air quality model validation data for nitrate, sulfate, ammonium ion and their precursors, Atmospheric Environment (1967), Volume 18, Issue 9, 1984, Pages 1815-1827, ISSN 0004-6981, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:49924
Deposited On:23 Sep 2014 17:35
Last Modified:10 Nov 2021 18:49

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