Long-range transport of sulfur from northeast Asia to Chengshantu, Shandong peninsula: Measurement and simulation

Observations of air pollutants were conducted at Chengshantu in January 199 6 to clarify the extent of trans-boundary pollution from the Asian continen t. A nested air quality prediction modeling system (NAQPMS), which included parameters on emission, transport, diffusion, deposition and transformatio n of sulfur oxides, was performed to compile sulfur concentrations over the observation site. The model calculation reproduced the observed variations of sulfur oxides and sulfate well, although the model calculations could n ot reproduce the extensively low sulfate concentrations. Using nesting impr oves the ability of the modeling system to capture peak episodes seen in th e observations. Calculation of the origins of deposited sulfur in each coun try with the NAQPMS shows that the long-range transport of sulfur is very s erious. For Japan, 49% of sulfur deposition was from other countries during the campaign period.