气候变化领域集成服务门户(CCPortal): Active molecular iodine photochemistry in the Arctic

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DOI	10.1073/pnas.1702803114
	Active molecular iodine photochemistry in the Arctic
	Raso A.R.W.; Custard K.D.; May N.W.; Tanner D.; Newburn M.K.; Walker L.; Moore R.J.; Huey L.G.; Alexander L.; Shepson P.B.; Pratt K.A.
发表日期	2017
ISSN	0027-8424
起始页码	10053
结束页码	10058
卷号	114 期号:38
英文摘要	During springtime, the Arctic atmospheric boundary layer undergoes frequent rapid depletions in ozone and gaseous elemental mercury due to reactions with halogen atoms, influencing atmospheric composition and pollutant fate. Although bromine chemistry has been shown to initiate ozone depletion events, and it has long been hypothesized that iodine chemistry may contribute, no previous measurements of molecular iodine (I2) have been reported in the Arctic. Iodine chemistry also contributes to atmospheric new particle formation and therefore cloud properties and radiative forcing. Here we present Arctic atmospheric I2 and snowpack iodide (I−) measurements, which were conducted near Utqiagvik, _ AK, in February 2014. Using chemical ionization mass spectrometry, I2 was observed in the atmosphere at mole ratios of 0.3–1.0 ppt, and in the snowpack interstitial air at mole ratios up to 22 ppt under natural sunlit conditions and up to 35 ppt when the snowpack surface was artificially irradiated, suggesting a photochemical production mechanism. Further, snow meltwater I− measurements showed enrichments of up to ∼1,900 times above the seawater ratio of I−/Na+, consistent with iodine activation and recycling. Modeling shows that observed I2 levels are able to significantly increase ozone depletion rates, while also producing iodine monoxide (IO) at levels recently observed in the Arctic. These results emphasize the significance of iodine chemistry and the role of snowpack photochemistry in Arctic atmospheric composition, and imply that I2 is likely a dominant source of iodine atoms in the Arctic. © 2017, National Academy of Sciences. All rights reserved.
英文关键词	Atmosphere; Cryosphere; Iodine; Photochemistry; Snowpack
语种	英语
scopus关键词	iodine derivative; sea water; Arctic; Article; boundary layer; irradiation; mass spectrometry; ozone depletion; photochemistry; priority journal; recycling; surface property
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158890
作者单位	Raso, A.R.W., Department of Chemistry, Purdue University, West Lafayette, IN 47907, United States, Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, United States; Custard, K.D., Department of Chemistry, Purdue University, West Lafayette, IN 47907, United States; May, N.W., Department of Chemistry, University of Michigan, Ann Arbor, MI 48109, United States; Tanner, D., School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States; Newburn, M.K., Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Walker, L., Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Moore, R.J., Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352, United States; Huey, L.G., School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United ...
推荐引用方式 GB/T 7714	Raso A.R.W.,Custard K.D.,May N.W.,et al. Active molecular iodine photochemistry in the Arctic[J],2017,114(38).
APA	Raso A.R.W..,Custard K.D..,May N.W..,Tanner D..,Newburn M.K..,...&Pratt K.A..(2017).Active molecular iodine photochemistry in the Arctic.Proceedings of the National Academy of Sciences of the United States of America,114(38).
MLA	Raso A.R.W.,et al."Active molecular iodine photochemistry in the Arctic".Proceedings of the National Academy of Sciences of the United States of America 114.38(2017).