Characteristics of sulfate in atmosphere over Xiamen waters and its fluxes to waters

One hundred and seven marine aerosol samples were collected during December 1988 to March 1990, and 3 dry deposition samples, 16 rain samples and 2 Cascade Impacter samples were collected from March to May 1990 at the southeast coast of the Xiamen Island.All the samples were analyzed for SO₄^2-, NO₃^-, Cl^-, Na⁺, NH₄⁺, using ion chromatography.
The results indicate that the concentration of sulfate in marine aerosols over the Xiamen waters appears to be of seasonal variation, in an order of winter > spring > autumn > summer.The mean sulfate concentration lor the total marine aerosol samples over the Xiamen waters is 9.37 μg/m³, respectively 0.89 and 8.48 μg/m³ for the seasalt and non-sea-salt sulfate.The distribution of sulfate shows a bimodal form with a peak in the coarse particle range which is derived from the sea-salt sulfate, and a peak in the fine particle range which is derived from the non-sea-salt sulfate.The total deposition of sulfate to the Xiamen waters is estimated to be 4.68g/m²·a, with dry and wet depositions being approximately 2.19g/m²·a respectively.