STI collects emissions-related data to improve emission inventories, create ground-up emissions estimates, and enhance ambient air quality measurements. Data collection techniques include telephone and mail surveys, monitoring traffic activity patterns, field surveys by trained observers, and emissions measurements.
From 2000 through 2003, STI scientists researched the causes of persistently high weekend ozone concentrations in California's South Coast Air Basin. For the National Renewable Energy Laboratory (NREL), we developed hypotheses for the "weekend effect" through a retrospective analysis of ambient and emissions data. For NREL, and through follow-on projects for the California Air Resources Board (ARB), we designed a field study that included telephone and mail surveys of small businesses and residences, acquisition of point source operations data, and monitoring of traffic activity patterns. Field study results were analyzed to test the initial hypotheses, enhance the current conceptual model of the weekend effect, and improve the ARB's emission inventories.
STI analysts trained field observers to collect emissions-related activity data for areas surrounding air quality monitoring sites. The results are being used to evaluate potential influences of local emissions sources on the air quality data. This work was performed in support of the California Regional PM10/PM2.5 Air Quality Study (CRPAQS).
STI completed two studies of agriculture-related emissions for the San Joaquin Valley Air Pollution Control District. Both studies involved telephone surveys of farm businesses. In the first study, STI analysts used the survey data to estimate emissions from irrigation pumps powered by internal combustion engines. In the second study, we gathered information about common farming practices and used the data to evaluate the potential effectiveness of voluntary PM emissions reduction strategies (such as the use of ground cover crops, the application of road dust suppressants, and the use of alternatives to agricultural burning).
STI scientists compiled an ammonia emission inventory for California's San Joaquin Valley. As a component of the study, we conducted field measurements of ammonia emission rates from a livestock facility, a farm, and a wastewater treatment plant. The results were used to reduce uncertainties in the ammonia inventory and to verify improved ammonia emission factors developed by other researchers. This work was performed for the California Air Resources Board.
STI collected data to improve biogenic emissions estimates for Maricopa County, Arizona and Ventura County, California. With a consultant, STI analysts developed locale-specific land-use data and plant-specific biomass factors. This information was used to customize biogenic emissions modeling tools and to prepare gridded biogenic emission inventories of VOC and NOx.
STI staff developed a software tool to query operators of offshore petroleum production platforms about industry operations. From the survey responses, we prepared an inventory of platform emissions that is used to model industrial impacts on the air quality of the Breton National Wildlife Refuge in the Gulf of Mexico. This project was performed for the Minerals Management Service of the U.S. Department of the Interior.