Real Scale Experiment of Pollution and Modification of Cloud by using a Vertical Shaft.

在岩手县釜石矿业公司某立井的人工云实验系统中，研究了二氧化硫溶解到云滴中并依次氧化为硫酸盐的过程。液滴、气溶胶和气体中的硫化物由多个高度的连续采样器收集。各高度硫化物的浓度表明，竖井底部释放的二氧化硫被云滴吸收，但氧化成硫酸盐的速度较慢，这可能是由于竖井中没有光和氧化剂。加湿器产生氯化钠和亚硫酸氢钠颗粒，注入井筒底部。颗粒的模态直径为0.1 ~ 0.5μm。未注入颗粒时，云滴的模态直径为7 μm。随着颗粒的注入，云滴的模态直径没有变化，但尺寸分布扩大到更大的直径。通过电子显微镜和X射线分析仪分析发现，到达井筒顶部的液滴中有50%以上含有注入颗粒的化学物质。但是，其他颗粒含有碳酸钙。结果表明，碳酸钙颗粒或表面包覆碳酸钙的矿物颗粒可能在大气中起凝结核的作用。

The process of sulfur dioxide dissolution into cloud droplets and its successive oxidation to sulfate were studied in an artificial cloud experimental system in a vertical shaft in Kamaishi mining company, Iwate prefecture. Sulfur compounds in droplets, aerosols and gas were collected by serial samplers at several heights. The concentrations of sulfur compounds at each height indicate that the released sulfur dioxide at the bottom of the shaft was absorbed by cloud droplets, but the oxidation rate to sulfate was slow which may be due to the absence of light and oxidants in the shaft.Sodium chloride and sodium hydrogensulfite particles were generated by humifier and injected into the base of shaft. Modal diameter of the particles is 0.1〜0.5μm. Without the particle injection, modal diameter of cloud droplets was 7 μm. With the particle injection, modal diameter of cloud droplets did not change, but the size distribution widened out to larger diameter.By using eletron microscope with X ray analyzer, we found that more than 50 % of the droplets, which arrived at top of the shaft, contained chemical species of the injected particles. But, the other particles cintained calsium carbonate. It shows that calsium carbonate particles or mineral particles coated with calsium carbonate on the surface may act as condensation nuclei in the atmosphere.