文章基本信息

标题：Measurement of loss rates of organic compounds in snow using in situ experiments and isotopically labelled compounds
本地全文：下载
作者：Erika von Schneidemesser ; James J. Schauer ; Martin M. Shafer 等
期刊名称：Polar Research
印刷版ISSN：1751-8369
出版年度：2012
卷号：31
期号：0
DOI：10.3402/polar.v31i0.11597
语种：English
出版社：Co-Action Publishing
摘要：Organic molecular marker compounds are widely used to identify emissions from anthropogenic and biogenic air pollution sources in atmospheric samples and in deposition. Specific organic compounds have been detected in polar regions, but their fate after deposition to snow is poorly characterized. Within this context, a series of exposure experiments were carried out to observe the post-depositional processing of organic compounds under real-world conditions in snow on the surface of the Greenland Ice Sheet, at the Summit research station. Snow was prepared from water spiked with isotopically labelled organic compounds, representative of typical molecular marker compounds emitted from anthropogenic activities. Reaction rate constants and reaction order were determined based on a decrease in concentration to a stable, non-zero, threshold concentration. Fluoranthene-d10, docosane-d46, hexadecanoic acid-d31, docosanoic acid-d43 and azelaic acid-d14 were estimated to have first order loss rates within surface snow with reaction rate constants of 0.068, 0.040, 0.070, 0.067 and 0.047 h-1, respectively. No loss of heptadecane-d36 was observed. Overall, these results suggest that organic contaminants are archived in polar snow, although significant post-depositional losses of specific organic compounds occur. This has implications for the environmental fate of organic contaminants, as well as for ice-core studies that seek to use organic molecular markers to infer past atmospheric loadings, and source emissions.Keywords: Snow; photochemistry; air pollution; Greenland; ArcticTo access the supplementary material to this article: 'Supplementary Figures & Table' and 'Supplementary File', please see Supplementary files in the column to the right (under Article Tools).(Published: 26 July 2012)Citation: Polar Research 2012, 31, 11597, http://dx.doi.org/10.3402/polar.v31i0.11597
关键词：Snow; photochemistry; air pollution; Greenland; Arctic