厦门海域大气颗粒态硫酸盐的分布特征及其入海通量

DISTRIBUTION OF CHARACTERISTICS PARTICLE SULFATE IN ATMOSPHERE OVER XIAMEN WATERS AND ITS FLUXES TO WATERS

厦门海域大气中颗粒态硫酸盐的浓度存在着季节性的变化规律,其浓度大小为:冬季大于春季大于秋季大于夏季.颗粒态硫酸盐的平均浓度估算为9.37μg/m^3,其中海盐源和非海盐源硫酸盐分别为0.89和8.48μg/m^3.硫酸盐在不同粒径颗粒物中的分布呈双峰型:粗颗粒硫酸盐来源于海盐,而细颗粒硫酸盐则非来自海盐.利用所采集的大气干、湿沉降的试样,测定了颗粒态硫酸盐的分布变化特征,并估算了大气输入厦门海域的颗粒态硫酸盐通量为5.17g/(m^2·a).

107 marine aerosol samples, 3 dry deposition samples, 16 rain samples and 2 Cascade Impacted samples were collected at the southeast coast of the Xiamen Island. All the samples were analyzed for SO_4~2-,NO3-,Cl-,Na+,NH4+,using ion chromatography. The results indicate that the concentrations of sulfate in marine aerosols over the Xiamen waters show seasonal variation, with a sequence of winter> spring > autumn > summer. The mean sulfate concentration for the total marine aerosol samples over the Xiamen waters is 9.37 μg/m3. The sea-salt and non-sea-salt sulfate are 0.89 and 8.48 μg/m3 respectively. 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 particle sulfate to the Xiamen waters was estimated to be 5.17 g/(m2·a), with dry and wet depositions being approximately 2.19 and 2.98 g/(ms·a)res-pectively.