AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Contributions of Semi-Volatile Compounds from Combustion Sources in Japan
YU MORINO, Satoru Chatani, Kiyoshi Tanabe, Yuji Fujitani, Tazuko Morikawa, Kei Sato, National Institute for Environmental Studies
Abstract Number: 235 Working Group: Regional and Global Air Quality and Climate Modeling
Abstract In Japan, emission factors of particulate matters (PM) from stationary combustion sources have been measured without dilution or cooling, thus semi-volatile compounds were not included in the PM emission inventory. Recently, contributions of semi-volatile compounds were analyzed by comparing measured PM concentrations from stationary combustion sources (e.g., heavy oil or gas combustion) before and after dilution. From these data, we modified emission inventory to include semi-volatile compounds from stationary combustion sources. Total emission rates of organic aerosol (OA), dominant contributor to semi-volatile compounds from large combustion sources, increased by a factor of five. Emissions of OA of this estimate became even higher than the total PM2.5 emissions of the previous estimate. In addition, road transport and biomass burning were the dominant OA sources in the previous estimate, while large combustion sources in industrial or power generation sector became the largest contributors to OA emissions over Japan. These results indicate that semi-volatile compounds from combustion sources had critical contributions to total PM2.5 emissions.
Contributions of semi-volatile compounds from combustion sources were also evaluated from simulations of a chemical transport model with a volatility basis set (VBS) module. Simulated OA concentrations drastically increased around urban and industrial areas, including Tokyo Metropolitan Area, both in winter and summer. On average, OA concentrations increased by a factor of 1.9-2.2 and 2.1-3.0 over Tokyo Metropolitan Area in winter and summer, respectively. By considering semi-volatile compounds from combustion sources, model performance of OA was improved in winter. However, in summer, OA concentrations were largely overestimated by the model which considers both semi-volatile compounds from combustion sources and chemical aging. Contributions of primary and secondary OA should be further evaluated from comparison with measurement data of organic compounds.