AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Highly-resolved Modeling of Emissions and Concentrations of Carbon Monoxide, Carbon Dioxide, Nitrogen Oxides, and Fine Particulate Matter in Salt Lake City, Utah
DANIEL MENDOZA, John Lin, Logan Mitchell, James Ehleringer, University of Utah
Abstract Number: 312 Working Group: Urban Aerosols
Abstract Accurate, high-resolution data on air pollutant emissions and concentrations are needed to understand human exposures and for policy purposes to manage pollutant sources. Quantification of uncertainties is also needed.
The work presented discusses an emissions inventory and concentration estimates for carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx) and fine particle (PM2.5) for the city of Salt Lake City, Utah. A comparison between measurement data and simulated concentrations from an atmospheric model (using inventory emissions), is also presented.
The emissions inventory for the criteria pollutants was constructed using the 2011 National Emissions Inventory (NEI). The spatial and temporal allocation methods from the Emission Modeling Clearinghouse data set are used to downscale the NEI data from annual and county-level resolution to hourly and 500m x 500m. Onroad mobile source emissions were estimated by combining a bottom-up emissions calculation approach for large roadway links within Salt Lake City with a top-down spatial allocation approach for other roadways. Vehicle activity data for road links were obtained from automatic traffic responder data and local sources. The emissions inventory for CO2 was obtained from the Hestia emissions data product at an hourly, building and road link resolution.
The AERMOD Gaussian plume dispersion model and the CALPUFF puff dispersion models were used to transport the resulting emissions and estimate air pollutant concentrations at an hourly 500m x 500m resolution. Modeled results were compared against measurements from a mobile lab traveling on pre-determined routes in the Salt Lake City area. The comparison between both approaches to concentration estimation highlights spatial locations and hours of high variability/uncertainty.
Results presented here will inform understanding of variability and uncertainty in emissions and concentrations in order to better inform future policy. This work will also facilitate the development of a systematic approach to incorporate measurement data and models to better inform estimates of pollutant concentrations.