title: Chinese province-scale source apportionments for sulfate aerosol in 2005 evaluated by the tagged tracer method.
abstract: Appropriate policies to improve air quality by reducing anthropogenic emissions are urgently needed. This is typified by the particulate matter (PM) problem and it is well known that one type of PM, sulfate aerosol (SO42-), has a large-scale impact due to long range transport. In this study we evaluate the source-receptor relationships of SO42-over East Asia for 2005, when anthropogenic sulfur dioxide (SO2) emissions from China peaked. SO2emissions from China have been declining since 2005-2006, so the possible maximum impact of Chinese contributions of SO42-is evaluated. This kind of information provides a foundation for policy making and the estimation of control effects. The tagged tracer method was applied to estimate the source apportionment of SO42-for 31 Chinese province-scale regions. In addition, overall one-year source apportionments were evaluated to clarify the seasonal dependency. Model performance was confirmed by comparing with ground-based observations over mainland China, Taiwan, Korea, and Japan, and the model results fully satisfied the performance goal for PM. We found the following results. Shandong and Hebei provinces, which were the largest and second largest SO2sources in China, had the greatest impact over the whole of East Asia with apportionments of around 10-30% locally and around 5-15% in downwind receptor regions during the year. Despite large SO2emissions, the impact of south China (e.g., Guizhou, Guangdong, and Sichuan provinces) was limited to local impact. These results suggest that the reduction policy in south China contributes to improving the local air quality, whereas policies in north and central China are beneficial for both the whole of China and downwind regions. Over Taiwan, Korea, and Japan, the impact of China was dominant; however, local contributions were important during summer.
authors.affiliation: Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba 270-1194, Japan. Electronic address: isyuichi@criepi.denken.or.jp.
authors.forename: Syuichi
authors.initials: S
authors.lastname: Itahashi
authors.affiliation: Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba 270-1194, Japan. Electronic address: haya@criepi.denken.or.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hayami
authors.affiliation: Meteorological Research Institute, Japan Meteorological Agency, 1-1 Nagamine, Tsukuba, Ibaraki 305-0032, Japan. Electronic address: yumimoto@mri-jma.go.jp.
authors.forename: Keiya
authors.initials: K
authors.lastname: Yumimoto
authors.affiliation: Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga Park, Kasuga, Fukuoka 816-8580, Japan. Electronic address: uno@riam.kyushu-u.ac.jp.
authors.forename: Itsushi
authors.initials: I
authors.lastname: Uno
mesh_terms: D000336:Aerosols / Q000032:analysis* / Q000737:chemistry; D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis* / Q000737:chemistry; D002681:China; D004784:Environmental Monitoring / Q000379:methods; D005202:Asia, Eastern; D007564:Japan; D008962:Models, Theoretical; D052638:Particulate Matter / Q000032:analysis / Q000737:chemistry; D056910:Republic of Korea; D012621:Seasons; D013458:Sulfur Dioxide / Q000032:analysis* / Q000737:chemistry; D013624:Taiwan
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D013458:Sulfur Dioxide
keywords: East Asia; Regional chemical transport model; Source apportionment; Sulfate aerosol; Tagged tracer method