Use of stable sulfur isotopes to identify sources of sulfate in Rocky Mountain snowpacks
Use of stable sulfur isotopes to identify sources of sulfate in Rocky Mountain snowpacks
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DOI：
10.1016/s1352-2310(00)00507-0
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发表时间：
2001-07-01
影响因子：
5
通讯作者：
Kester, CL
中科院分区：
文献类型：
--
作者：
Mast, MA;Turk, JT;Kester, CL
1993年至1999年，在沿着和靠近大陆分水岭的52个高海拔地点的网络中监测了大量积雪样品中的稳定硫同位素比值和主要离子。收集这些信息是为了更好地确定落基山脉偏远地区的大气沉积，并帮助确定冬季沉积中硫酸盐的主要来源地区。个别地点的S-34年平均值为每千份+4.0至+8.2份，标准差为每千份0.4至1.6份。所有样品的化学成分都非常稀，呈弱酸性;平均硫酸盐浓度范围为2.4至12.2 mu eq 1（-1），pH值范围为4.82至5.70。在这项研究中测量的三角洲S-34值的范围表明，在落基山脉积雪硫主要来自人为来源。在新墨西哥州、科罗拉多和怀俄明州南部，观测到三角洲S-34与纬度之间几乎呈线性关系，这表明该网络南部的积雪硫酸盐来自两个同位素不同的源区。由于该地区二氧化硫的主要点源是燃煤电厂，这种模式可能反映了电厂燃烧的煤的同位素组成的变化。在三角洲S-34的地理模式更远的北部在怀俄明州和蒙大拿州的网站是不太明显，也许反映了在网络的北方部分的主要点源的SO2的缺乏。出版社：Elsevier Science Ltd
Stable sulfur isotope ratios and major ions in bulk snowpack samples were monitored at a network of 52 high-elevation sites along and near the Continental Divide from 1993 to 1999. This information was collected to better define atmospheric deposition to remote areas of the Rocky Mountains and to help identify the major source regions of sulfate in winter deposition. Average annual delta S-34 values at individual sites ranged from + 4.0 to + 8.2 parts per thousand and standard deviations ranged from 0.4 to 1.6 parts per thousand. The chemical composition of all samples was extremely dilute and slightly acidic; average sulfate concentrations ranged from 2.4 to 12.2 mu eq 1(-1) and pH ranged From 4.82 to 5.70. The range of delta S-34 values measured in this study indicated that snowpack sulfur in the Rocky Mountains is primarily derived from anthropogenic sources. A nearly linear relation between delta S-34 and latitude was observed for sites in New Mexico, Colorado, and southern Wyoming, which indicates that snowpack sulfate in the southern part of the network was derived from two isotopically distinct source regions. Because the major point sources of SO2 in the region are coal-fired powerplants, this pattern may reflect variations in the isotopic composition of coals burned by the plants. The geographic pattern in delta S-34 for sites farther to the north in Wyoming and Montana was much less distinct, perhaps reflecting the paucity of major point sources of SO2 in the northern part of the network. Published by Elsevier Science Ltd.