ソース・レセプター手法を用いた西日本・日本海沿岸へのPM_2.5越境輸送の解析

抄録

In order to have a better understanding of Asian scale trans-boundary PM_2.5 contribution over western Japan and Japan Sea side area, source-receptor analysis based on the chemical transport model was conducted. We used GEOS Chem model and divided the Asian model domain into 15 major source regions, and the emission intensity sensitivity (source-receptor relationship) was examined. Long-term aerosol observation data at the Chikushi-campus of Kyushu University, Fukuoka, Japan, from December 2013 to March 2015 was used to validate the model performance. We also confirmed that the numerical model generally captured the observed time variation of PM_2.5 at remote islands (Miyakojima, Fukue, Oki, and Sado) quite well. We showed that the contribution of Japanese domestic emission to the annual averaged PM_2.5 concentration at Fukuoka was only 20%, and the other 80% of PM_2.5 was coming from outside of Japan (19.6% and 16.3% were coming from central north China region and Korea, respectively). Modeled source-receptor ratio in Fukuoka and the observed PM_2.5 concentration decrease in Beijing-Tianjin-Shandong area explained the recent decreasing trend of PM_2.5 (13% decrease from 2014 to 2016) at Fukuoka.