THE SEASONAL VARIATION OF SO2, SO4= AND HNO3(g) DRY DEPOSITION VELOCITIES OVER EASTERN CHINA

SO2, SO4= and HNO3(g) dry deposition velocities and their seasonal variations at a height of approximately 40m above sruface over eastern China were calculated using MM4 mesescale meteorological model by combining detailed landuse data with meteorological information throughout 1992. It was found that spatial and time variations of SO2, SO4= and HNO3(g) dry deposition velocities are very notable because of the combining influences of meteorological conditions and landuse. SO2, SO4= and HNO3 (g) domain-averaged dry deposition velocities vary among 0.088-1.275cm/s, 0.014-0.287cm/s and 0.060-5.250cm/s, respectively, the averaged values are 0.430cm/s, 0.118cm/s and 1.123cm/s, respectively. There was a maximun value region of domain-averaged SO2 deposition velocity in Badain Jarain Desert and Tengger Desert, but for SO4= and HNO3 (g), there was also an other maximum value region in northern part of Yun-Gui Plateau except above mentioned areas. For one year period, SO2 and HNO3(g) maximum domain-averaged dry deposition velocities appeared in July 1992, which was 0.552cm/s and 1.518cm/s, respectively, but for SO4=, that appeared in September, and was 0.096cm/s. These values were all in the field measurement scope.