Spatial distribution of the source-receptor relationship of sulfur in Northeast Asia
1Research Center for Adv. Science and Technology, The University of Tokyo, Tokyo, Japan
2Kyoto University, Kyoto, Japan
3Asia Center for Air Pollution Research, Niigata, Japan
4Japan NUS Co. LTD, Tokyo, Japan
*now at: Meteorological Research Institute, Japanese Meterological Agency, Tsukuba, Japan
Abstract. The spatial distribution of the source–receptor relationship (SRR) of sulfur over Northeast Asia was examined using an off-line coupled meteorological/chemical transport model (MM5/RAQM). The simulation was conducted for the entire year of 2002. The results were evaluated using monitoring data for six remote stations of the Acid Deposition Monitoring Network in East Asia (EANET). The modeled SO2 and O3 concentrations agreed well with the observations quantitatively. The modeled aerosol and wet deposition fluxes of SO42− were underestimated by 30% and 50%, respectively, whereas the modeled precipitation was overestimated by 1.6 to 1.9 times. The domain was divided into 5 source–receptor regions: I, North China; II, Central China; III, South China; IV, South Korea; and V, Japan. The sulfur deposition in each receptor region amounted to about 50–75% of the emissions from the same region. The largest contribution to the deposition in each region was the domestic origin, accounting for 53–84%. The second largest contribution after the domestic origin was due to region II, supplying 14–43%, outside region II itself. The spatial distributions of the SRRs revealed that subregional values varied by about two times more than regional averages due to nonuniformity across the deposition fields. Examining the spatial distributions of the deposition fields was important for identifying subregional areas where the deposition was highest within a receptor region. The horizontal distribution changed substantially according to season.