AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Impact of Long-Range Transport of Central America Biomass Burning Emissions on Air Quality in Texas
QIANJIN ZHENG, David Ramirez, Min Zhong, Texas A&M University-Kingsville
Abstract Number: 379 Working Group: Biomass Combustion: Emissions, Chemistry, Air Quality, Climate, and Human Health
Abstract Every spring, transported smoke from Central America reaches South Texas resulting in elevation of daily PM2.5 and impaired air quality. The objectives of this study are to examine the transport of smoke, analyze the spatial distribution of air pollutants, and quantify the impact of biomass burning on local air quality using the Weather Research and Forecasting model coupled with Chemistry model (WRF-Chem). The model domain covers Central America, Mexico, and the southern U.S. at 18 km horizontal resolution. Four gas-phase and aerosol mechanisms were tested to select the best mechanism in predicting gases, aerosols, and aerosol direct and indirect effects. Then we employed two global fire emission inventories, the Fire INventory from NCAR (FINN) and the Global Fire Emissions Database (GFED), for the air quality simulations. Overall, the model reproduced the spatial and temporal patterns of PM2.5 which were consistent with the observed data. CBMZ-MADE/SORGAM mechanism provided the best simulation results which were closer to observations with a correlation coefficient of 0.676, among the four tested mechanisms. Smoke plumes from Central America spread across certain areas in South Texas and affected the local air quality, with enhancements of up to 15 ppb O3 and 20-30 µg/m3 of PM2.5. Moreover, it took around two days to lower down the PM2.5 concentrations to the background level. Our work indicated that the boundary conditions from the WRF-Chem model form both gas-phase and aerosol pollutants contributed significantly in the simulation of all four mechanisms. Our study highlighted that long-range transport of biomass burning emissions should be considered when evaluating the relative effectiveness of local emission control programs, which could be helpful on the determination of compliance with National Ambient Air Quality Standards.
Keywords: Biomass Burning, WRF-Chem, Central American, Texas, Air pollution, Air quality