A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons
A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons
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DOI：
10.5194/acp-17-11929-2017
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发表时间：
2017-10
影响因子：
6.3
通讯作者：
D. Oram;M. Ashfold;J. Laube;Lauren J. Gooch;S. Humphrey;W. Sturges;Emma Leedham-Elvidge;Grant L. Forster;N. Harris;Mohammed Iqbal Mead;A. Samah;Siew Moi Phang;Chang‐Feng Ou‐Yang;N. Lin;Jia‐Lin Wang;A. Baker;C. Brenninkmeijer;David Sherry
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文献类型：
--
作者：
D. Oram;M. Ashfold;J. Laube;Lauren J. Gooch;S. Humphrey;W. Sturges;Emma Leedham-Elvidge;Grant L. Forster;N. Harris;Mohammed Iqbal Mead;A. Samah;Siew Moi Phang;Chang‐Feng Ou‐Yang;N. Lin;Jia‐Lin Wang;A. Baker;C. Brenninkmeijer;David Sherry
抽象的。正在通过《蒙特利尔议定书》大幅有效地减少长期消耗臭氧层物质的排放，其有效性可以从许多消耗臭氧层物质大气丰度的下降中看出。剩余的一个重要不确定性涉及极短寿命物质的作用，由于其大气寿命相对较短(不到6个月)，不受《蒙特利尔议定书》的管制。最近的研究发现，全球对流层中一种VSLS--二氯甲烷(CH2Cl2)的丰度出现了莫名其妙的增加，在过去十年中增加了约60%。在这里，我们报告了几种含氯VSLS(氯-VSLS)的显著增强，包括在东亚和东南亚地面和对流层上层空气中观察到的CH2Cl2和CH2ClCH2Cl(1，2-二氯乙烷)。有时，海洋边界层的地面观测数据比以前报告的高出一个数量级，而上层对流层数据比预期高出3倍。此外，我们还提供了大气输送机制的进一步证据，在这种机制下，来自东亚的大量工业污染，包括这些氯化的VSLS，可以迅速和定期地输送到西太平洋的热带地区，然后上升到热带对流层高层。后一区域是进入平流层的空气的主要供应者，因此这一机制与东亚不断增加的氯-VSLS排放相结合，可能会减缓平流层臭氧预期的恢复。
Abstract. Large and effective reductions in emissions of long-lived ozone-depleting substance (ODS) are being achieved through the Montreal Protocol, the effectiveness of which can be seen in the declining atmospheric abundances of many ODSs. An important remaining uncertainty concerns the role of very short-lived substances (VSLSs) which, owing to their relatively short atmospheric lifetimes (less than 6 months), are not regulated under the Montreal Protocol. Recent studies have found an unexplained increase in the global tropospheric abundance of one VSLS, dichloromethane (CH2Cl2), which has increased by around 60 % over the past decade. Here we report dramatic enhancements of several chlorine-containing VSLSs (Cl-VSLSs), including CH2Cl2 and CH2ClCH2Cl (1,2-dichloroethane), observed in surface and upper-tropospheric air in East and South East Asia. Surface observations were, on occasion, an order of magnitude higher than previously reported in the marine boundary layer, whilst upper-tropospheric data were up to 3 times higher than expected. In addition, we provide further evidence of an atmospheric transport mechanism whereby substantial amounts of industrial pollution from East Asia, including these chlorinated VSLSs, can rapidly, and regularly, be transported to tropical regions of the western Pacific and subsequently uplifted to the tropical upper troposphere. This latter region is a major provider of air entering the stratosphere, and so this mechanism, in conjunction with increasing emissions of Cl-VSLSs from East Asia, could potentially slow the expected recovery of stratospheric ozone.