Spatial and Temporal Distribution of Atmospheric Nitric Acid and Particulate Nitrate Concentrations in the Los Angeles Area
Abstract
A 1-year atmospheric measurement program was conducted throughout the South Coast Air Basin in the greater Los Angeles area during 1986 to determine the long-term average concentration patterns of gaseous HNO_3, and aerosol nitrates. Upwind of the air basin at San Nicolas Island, HNO_3, levels are very low, averaging 0.3 µg m^(-3) (0.1 ppb) over the year 1986. Annual average HNO_3 concentrations ranged from 3.1 µg m^(-3) (1.2 ppb) near the Southern California coast to 6.9 µg m^(-3) (2.7 ppb) at an inland site in the San Gabriel Mountains. At most monitoring stations, a majority of the inorganic nitrate (HNO_3 plus its reaction product, aerosol nitrate) was in the aerosol phase. Conversion of HNO_3 to aerosol nitrates was most pronounced at Rubidoux, near Riverside, CA, where on the average 94% of the inorganic nitrate was found in the aerosol phase, and where fine particle nitrate concentrations exceeded 109 pg µg^(-3), during the peak 24-h period examined.
Additional Information
© 1992 American Chemical Society. Received for review April 3, 1992. Accepted April 6, 1992. This work was supported by the California Air Resources Board under agreement A4-144-32. Air monitoring sites were provided through the cooperation of the South Coast Air Quality Management District, the U.S. Forest Service, and the U.S. Navy. Special thanks are given to Jay Rosenthal, Carl Otten, Grady-Jim Roberts, and Lloyd Willet for their assistance in transporting samples and operating the samplers at San Nicolas Island. Betsy Andrews, Sandra Blumhorst, David Cole, Nancy Drehwing, Doug Gray, Mike Jones, Philip Lin, Havey Liu, and Frank Vasquez of the California Institute of Technology assisted with the field experiments, laboratory analyses, and database management aspects of the project.Additional details
- Eprint ID
- 68743
- DOI
- 10.1021/es00032a016
- Resolver ID
- CaltechAUTHORS:20160629-111744859
- A4-144-32
- California Air Resources Board
- Created
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2016-06-29Created from EPrint's datestamp field
- Updated
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2021-11-11Created from EPrint's last_modified field