气候变化领域集成服务门户(CCPortal): Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere

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DOI	10.1073/pnas.1922486117
	Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere
	Saiz-Lopez A.; Travnikov O.; Sonke J.E.; Thackray C.P.; Jacob D.J.; Carmona-García J.; Francés-Monerris A.; Roca-Sanjuán D.; Ulises Acuña A.; Dávalos J.Z.; Cuevas C.A.; Jiskra M.; Wang F.; Bieser J.; Plane J.M.C.; Francisco J.S.
发表日期	2020
ISSN	0027-8424
起始页码	30949
结束页码	30956
卷号	117 期号:49
英文摘要	Mercury (Hg), a global contaminant, is emitted mainly in its elemental form Hg0to the atmosphere where it is oxidized to reactive HgIIcompounds, which efficiently deposit to surface ecosystems. Therefore, the chemical cycling between the elemental and oxidized Hg forms in the atmosphere determines the scale and geographical pattern of global Hg deposition. Recent advances in the photochemistry of gas-phase oxidized HgIand HgIIspecies postulate their photodissociation back to Hg0as a crucial step in the atmospheric Hg redox cycle. However, the significance of these photodissociation mechanisms on atmospheric Hg chemistry, lifetime, and surface deposition remains uncertain. Here we implement a comprehensive and quantitative mechanism of the photochemical and thermal atmospheric reactions between Hg0, HgI, and HgIIspecies in a global model and evaluate the results against atmospheric Hg observations. We find that the photochemistry of HgIand HgIIleads to insufficient Hg oxidation globally. The combined efficient photoreduction of HgIand HgIIto Hg0competes with thermal oxidation of Hg0, resulting in a large model overestimation of 99% of measured Hg0and underestimation of 51% of oxidized Hg and ∼66% of HgIIwet deposition. This in turn leads to a significant increase in the calculated global atmospheric Hg lifetime of 20 mo, which is unrealistically longer than the 3-6-mo range based on observed atmospheric Hg variability. These results show that the HgIand HgIIphotoreduction processes largely offset the efficiency of bromine-initiated Hg0oxidation and reveal missing Hg oxidation processes in the troposphere. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Atmospheric chemistry; Atmospheric modeling; Gas-phase mercury reactivity; Mercury photoreduction; Tropospheric chemistry
语种	英语
scopus关键词	bromine; mercury; Article; concentration (parameter); geography; oxidation; photochemistry; photolysis; priority journal; simulation; steady state; troposphere; wet deposition
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/160697
作者单位	Saiz-Lopez, A., Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano, Spanish National Research Council (CSIC), Madrid, 28006, Spain; Travnikov, O., Meteorological Synthesizing Centre-East of EMEP, Moscow, 115419, Russian Federation; Sonke, J.E., Geosciences Environnement Toulouse, CNRS/Observatoire Midi-Pyrenees (OMP), Universite de Toulouse, Toulouse, 31400, France; Thackray, C.P., Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States; Jacob, D.J., Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States; Carmona-García, J., Institut de Ciencia Molecular, Universitat de Valencia, Valencia, 46071, Spain; Francés-Monerris, A., Departamento de Quimica Fisica, Universitat de Valencia, Valencia, 46100, Spain, Universite de Lorraine, CNRS, Laboratoire de Physique et Chimie Theoriques (LPCT), Nancy, F-54000, France; Roca-Sanjuán, D., Ins...
推荐引用方式 GB/T 7714	Saiz-Lopez A.,Travnikov O.,Sonke J.E.,et al. Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere[J],2020,117(49).
APA	Saiz-Lopez A..,Travnikov O..,Sonke J.E..,Thackray C.P..,Jacob D.J..,...&Francisco J.S..(2020).Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.Proceedings of the National Academy of Sciences of the United States of America,117(49).
MLA	Saiz-Lopez A.,et al."Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere".Proceedings of the National Academy of Sciences of the United States of America 117.49(2020).