Elucidation of the long distance transportation of sulfate ion from Asia Continent based on sulfur isotope

1994年10月~ 12月每24 h采集一次降水。1995. 测定了样品的主要化学成分和硫同位素比值。5 - 8月氯离子浓度低于2 ppm， 9月及以后氯离子浓度上升至15 ppm。而Cl<1 ppm降水样品的Na/Cl比值大多在0.1 ~ 0.5之间，低于海水（0.56）。这表明，夏季人为来源的氯离子的贡献显著。5 ~ 8月NssSO4浓度为0 ~ 2.5 ppm， 9月以后上升至5 ppm。ppm中NO3/nssSO4比值从5月（0.7 ~ 1.2）到12月（0.2 ~ 0.6）逐渐降低。5 - 7月，nssSO4的δ S为1 - 3 / mill。δ S值大于零表明即使在夏季，硫酸盐离子也从亚洲大陆输送过来。硫同位素比值9月为0-3 /磨，11 - 12月为0-7 /磨。这表明大陆源SO4的贡献随着季节的变化而增加。δ S与NO3/nssSO4比值图显示，大部分降水分布在两个端点之间。一个终点，δ S为5 /磨，NO3/nssSO4为0.2，这是中国北方煤烟排放的典型终点。另一个终点是在NO3/nssSO4为1.5的情况下，δ S -2 / mill，这在日本的石油燃气中很常见。这表明从亚洲大陆运来的硫酸盐离子与当地的硫酸盐离子以不同的比例混合。

Precipitation was collected every 24 hours during Oct. 1994-Dec. 1995. Samples collected were measured their major chemical compositions and sulfur isotope ratio. Chloride ion concentration is lower than 2 ppm in May-August and increases up to 15 ppm on and after Septmber. However most of Na/Cl ratios of precipitation samples with Cl<1 ppm range 0.1-0.5 and are lower than that of sea water (0.56). This suggests that chloride ion with anthropogenic origin significantly contributes in summer. NssSO4 concentration is 0-2.5 ppm in May-August and on and after September it increased up to 5 ppm. NO3/nssSO4 ratio in ppm gradually decreases from May (0.7-1.2) to December (0.2-0.6). Delta S of nssSO4 is-1 to 3 per mill in May-July. Delta S values higher than zero suggest that even in summer season sulfate ion is transported from Asia Continent. Sulfur isotope ratio is 0-3 per mill in September and 0-7 per mill in November-December. This suggests that the contribution of SO4 with continental origin increase with the changes of seasons from fall to winter. Delta S versus NO3/nssSO4 ratio plot shows that most precipitation distribute between two end points. One end point, delta S of 5 per mill and NO3/nssSO4 of 0.2, is typical for coal fume exhausted from northern China. The other end point, delta S of-2 per mill with NO3/nssSO4 of 1.5, is common for petroleum combustion gas in Japan. This fact suggests that sulfate ion transported from Asia Continent is mixed with local sulfate ion with various ratios.