Measurements of methanesulphonic acid in Antarctic ice
Measurements of methanesulphonic acid in Antarctic ice
复制标题
南极冰中甲磺酸的测量
作者：
C. Saigne;M. Legrand
二甲硫醚（DMS）主要由海洋生物活动产生，在大气硫收支中发挥着重要作用1。甲磺酸 (MSA) 和二氧化硫 (SO2，以下转化为非海盐 (n.s.s.) 硫酸盐）是 DMS2 的主要氧化产物。与 n.s.s 相反。硫酸盐有其他来源（例如火山、陆地硫酸盐），MSA 代表了海洋生物活动的明确指标。此前曾在低纬度和中纬度地区的海洋气溶胶3-5以及降水和极地冰5,6中对MSA进行过研究；在这里，我们展示了在南极冰层中进行的 54 项 MSA 测量。沿海地区降水量表现出出乎意料的高（高达 100%）MSA/n.s.s。 SO2-4 重量比 (r) 与中纬度海洋大气中常见值的比较3。在较高海拔 (2,000 m) 的热值表明海洋生物输入具有更大的全球意义。 MSA 浓度（几个 p.p.b.）证实了 n.s.s.南极冰层中的硫酸盐主要来源于海洋生物活动。在最后一个冰河时期，MSA 含量比现在高 2-5 倍。这项高纬度降水研究证明了重建过去具有全球意义的海洋生物活动的可行性。
Dimethylsulphide (DMS), mainly produced by marine biogenic activity, plays an important role in the atmospheric sulphur budget1. Methanesulphonic acid (MSA) and sulphur dioxide (SO2, hereafter converted into non-sea-salt (n.s.s.) sulphate) are the main oxidation products of DMS2. As opposed to n.s.s. sulphate, which has other sources (for example, volcanoes, terrestrial sulphate), MSA represents an unequivocal indicator of marine biogenic activity. MSA has previously been investigated in marine aerosols at low and mid-latitudes3–5as well as in precipitations and polar ice5,6; here we present 54 MSA measurements made in Antarctic ice. Coastal area precipitations exhibit unexpectedly high (up to 100%) MSA/n.s.s. SO2–4weight ratios (r) compared with values commonly observed in mid-latitude marine atmospheres3. At higher elevations (2,000 m) thervalues suggest a marine biogenic input of more global significance. The MSA concentrations (several p.p.b.) confirm that the n.s.s. sulphate in Antarctic ice is mainly derived from marine biogenic activity. During the last ice age, MSA contents were 2–5 times higher than today. This study of high-latitude precipitations demonstrates the feasibility of reconstructing past marine biogenic activity of global significance.