ATMOSPHERIC NON-SEA-SALT SULFATE, NITRATE AND METHANESULFONATE OVER THE CHINA-SEA

To characterize atmospheric particulate non-sea-salt (nss) sulfate, ni trate, methanesulfonate (MSA), and selected trace elements over the Ch ina Sea, aerosol sampling was conducted at Qingdao and Xiamen, which a re on the coast of China, and over offshore regions of the East China Sea. The atmospheric concentrations of nss sulfate and nitrate were mu ch higher along the coast of the China Sea than over remote oceans, wi th mean values of 10 to 12 mu g m(-3) for nss sulfate and 5.6 to 7.7 m u g m(-3) for nitrate. The mean concentrations of atmospheric MSA rang ed from 0.029 to 0.066 mu g m(-3) over the China Sea; these are compar able to values from other coastal sites and remote oceans. Both MSA an d nss sulfate are concentrated in particles less than or equal to 0.5 mu m in diameter, while nitrate shows a bimodel distribution. There wa s no dear correlation between nss sulfate and MSA concentrations, with the ratios of nss sulfate to MSA (60-870) being substantially higher than those over remote oceans. Based on a biogenic nss-sulfate/MSA rat io of 18 obtained from the remote North Pacific, the estimated anthrop ogenic sulfate accounts for 81-97% of the total nss sulfate over the C hina Sea. Results of factor analyses suggest that coal combustion is t he dominate source,for anthropogenic sulfate over the basin of the Chi na Sea. Oil combustion appears to be an additional important contribut or for anthropogenic sulfate in the region of the East China Sea, but this feature does not exist in the South China Sea region. Pyrometallu rgical nonferrous metal smelting is among the additional sources for n ss sulfate in this region.