Tine Bases Of Particulate Sulfate Aed Nitrate In The Atmosphere—A Review

Size distributions for airborne mass of sulfate reported in the literature show a submicron peak for nearly all the locations at which data were obtained. Data from continental sites have mass median aerodynamic diameters (MMD) averaging 0.52/µm. Data from marine sites show appreciable sulfate on supermicron as well as submicron particles, with an average MMD of 2.3/µm. When used in dry deposition models, the size distribution data for continental areas yield average deposition velocities of 0.1-0.2 cm s^-1 for vegetation, snow and water. The size data for marine areas yield average deposition velocities of 0.5-0.6 cm s^-1 for water. In contrast to the data for sulfate, the quality of the size distribution data which have been reported for aerosol nitrate is uncertain due to potential sampling interferences.