A Comparison of Modeled and Observed Sulfur Concentration of Precipitation in China

摘要

The transport and deposition of sulfur oxides in East Asia region was calculated using an Eulerian long - range transport model for several cases. The calculated wet depositions were compared with the monthly averaged SO_4~(2-) concentrations in precipitation observed at 69 locations widely covering China from July through December of 1992. Though the chemical reactions and the depositions in the model are treated by simple first - order processes, calculated values including temporal variations showed reasonable agreement with the observation at most locations. Sensitivity of SO_4~(2-) concentrations in precipitation to various values for wet deposition coefficients, chemical conversion rates from SO_2 to SO_4~(2-) and the height of precipitating clouds determined by the relative humidity were also investigated. The calculated wet depositions were less sensitive to wet deposition coefficients and chemical conversion rates, in comparison with that to the height of precipitating clouds. These results indicate the relative importance of the information of precipitation applied to the model calculations.