Research Projects

Project at a Glance

Project Status: complete

Report Published May 1998:

Title: Temporal, spatial, and ambient temperature effects in the Sacramento modeling region.

Principal Investigator / Author(s): Rocke, David M

Contractor: UC Davis

Contract Number: 94-333

Research Program Area: Atmospheric Processes

Topic Areas: Modeling


The objective of this study is to identify and investigate important temporal and spatial variations in factors that affect emissions in the Sacramento modeling region, especially from non-road mobile sources and industrial surface coatings and related process solvents. In addition the project assesses the effect of ambient temperature on emissions from those sources. To accomplish the objective, this study develops spatial activity indicators and temporal activity profiles for the emission source categories included in the study. Specifically, a geographical information system (GIS) based approach is developed to spatially allocate regional or county-level emissions to units such as grid cells used in photochemical air quality simulation models. Statistical models are developed by which the values of spatial surrogates can be estimated and updated using widely available data such as those of land uses, population census and the U.S. Census Bureau's topographically integrated geographic encoding and referencing (TIGER) files. Most temporal activity profiles developed in this study are based on our surveys of emission source facilities in the study area. The temporal activity profiles can be used to scale the annual emission estimated by the ARB to determine monthly, weekly (day of the week) and hourly emissions. The monthly activity profiles of the farm equipment category are calculated from crop-specific sample production cost estimates developed by the county farm advisors and the University of California Cooperative Extension. The effects of ambient temperature and weather on the source activities are estimated based on the data from our surveys.


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

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