Research Projects

Project at a Glance

Project Status: complete

Report Published September 1987:

Title: Model and data base description for California's level 1 PM10 assessment package

Principal Investigator / Author(s): Watson, John G

Contractor: Desert Research Institute; Sonoma Technology, Inc.; Environmental Monitoring & Services, Inc.

Contract Number: A4-155-32

Research Program Area: Atmospheric Processes

Topic Areas: Modeling


The Level I PM10 Assessment Package consists of air quality models and interfaces to data bases available to the California Air Resources Board. All software and data bases are manipulated on IBM/PC compatible microcomputers in the DOS operating environment.

The modeling software consists of: 1) a BMDP computer program for the Principal Components Analysis receptor model; 2) a U.S. EPA program for the Chemical Mass Balance receptor model; and 3) a U.S. EPA program for the Industrial Source Complex Short-Term dispersion model, modified for error propagation. These models are used sequentially to identify the major source types contributing to PM10 levels in California, to estimate those source-type contributions, and to apportion contributions to source subtypes.

Data bases which are accessed by these models include: 1) the ARB dichotomous sampler network, 2) the Kern County gridded emissions inventory, 3) EPA's source composition library and 4) National Weather Service surface and upper air station data. Software has been created to select data from these data bases and convert them to appropriate model input formats.

The Level I PM10 Assessment Package is applied to data from the Bakersfield-Chester PM10 sampling site, using June 17, 1983, as an example. The results of this application indicated that geological material was the major contributor to the high PM10 concentration on the example day, and that the source sub-type with the largest contribution was resuspended paved-road dust. The example is illustrative rather than conclusive, however, and the uncertainties associated with the Level I apportionment are great. The Level I PM10 Assessment Package is intended primarily to aid and focus the design of measurement and modeling studies to support Level II PM10 assessment.


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

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