TITLE:
Anthropogenic Source Contributions to Ozone Formation in the Greater Houston Area
AUTHORS:
Iqbal Hossan, Hongbo Du, Raghava R. Kommalapati
KEYWORDS:
Anthropogenic Sources, CAMx, Model Sensitivity, Ozone Precursors
JOURNAL NAME:
Journal of Environmental Protection,
Vol.12 No.4,
April
21,
2021
ABSTRACT: The Houston-Galveston-Brazoria (HGB) area of Texas has historically
experienced severe air pollution events with high concentrations of ozone (O3)
during the summer season. This study evaluates the contribution of different
anthropogenic sources to ozone formation in the HGB area. The Emission
Processing System (EPS3) is used to process emission files in four different
scenarios (Base case as including All emission sources (BC), All sources— Area
sources (AMA), All sources—Point sources (AMP), and All sources— Mobile sources
(AMM). These files are used as input in photochemical modeling with the
Comprehensive Air Quality Model with Extensions (CAMx) to simulate ozone
formation. The data is analyzed for daily maximum ozone concentrations and contribution of source categories at three air
quality monitoring locations (La Porte Sylvan beach-C556, Houston Texas
avenue-C411, and Texas city in Galveston-C683) for a study period of June 1-June 30,
2012. The contribution of the point sources to ozone formation is dominated at
all three locations, followed by mobile sources and area sources on high ozone
days. The relative contributions of point sources are 27.51% ± 3.53%, 21.45% ± 7.36%, and 30.30% ± 9.36%; and
mobile sources are 18.27% ± 2.22%, 20.60% ± 6.89%, and 18.61% ± 7.43%;
and area sources were 4.2% ± 1.65%, 5.21% ± 1.59%, and 3.72% ± 1.52% at C556,
C411, and C683, respectively. These results demonstrate the importance of
regulatory focus on controlling point and mobile source emissions for NAAQS
attainment in the study region.