气候变化领域集成服务门户(CCPortal): Effect of sea salt aerosol on tropospheric bromine chemistry

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DOI	10.5194/acp-19-6497-2019
	Effect of sea salt aerosol on tropospheric bromine chemistry
	Zhu L.; Jacob D.J.; Eastham S.D.; Sulprizio M.P.; Wang X.; Evans M.J.; Chen Q.; Alexander B.; Koenig T.K.; Volkamer R.; Huey L.G.; Le Breton M.; Bannan T.J.; Percival C.J.
发表日期	2019
ISSN	16807316
起始页码	6497
结束页码	6507
卷号	19 期号:9
英文摘要	Bromine radicals influence global tropospheric chemistry by depleting ozone and by oxidizing elemental mercury and reduced sulfur species. Observations typically indicate a 50 % depletion of sea salt aerosol (SSA) bromide relative to seawater composition, implying that SSA debromination could be the dominant global source of tropospheric bromine. However, it has been difficult to reconcile this large source with the relatively low bromine monoxide (BrO) mixing ratios observed in the marine boundary layer (MBL). Here we present a new mechanistic description of SSA debromination in the GEOS-Chem global atmospheric chemistry model with a detailed representation of halogen (Cl, Br, and I) chemistry. We show that observed levels of SSA debromination can be reproduced in a manner consistent with observed BrO mixing ratios. Bromine radical sinks from the HOBr + S(IV) heterogeneous reactions and from ocean emission of acetaldehyde are critical in moderating tropospheric BrO levels. The resulting HBr is rapidly taken up by SSA and also deposited. Observations of SSA debromination at southern midlatitudes in summer suggest that model uptake of HBr by SSA may be too fast. The model provides a successful simulation of free-tropospheric BrO in the tropics and midlatitudes in summer, where the bromine radical sink from the HOBr + S(IV) reactions is compensated for by more efficient HOBr-driven recycling in clouds compared to previous GEOS-Chem versions. Simulated BrO in the MBL is generally much higher in winter than in summer due to a combination of greater SSA emission and slower conversion of bromine radicals to HBr. An outstanding issue in the model is the overestimate of free-tropospheric BrO in extratropical winter-spring, possibly reflecting an overestimate of the HOBr/HBr ratio under these conditions where the dominant HOBr source is hydrolysis of BrNO3. © Author(s) 2019.
语种	英语
scopus关键词	aerosol; atmospheric chemistry; boundary layer; bromine; hydrolysis; marine atmosphere; mixing ratio; radical; sea salt; seawater; troposphere; water chemistry
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144410
作者单位	John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States; Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, United States; Laboratory for Aviation and the Environment, Massachusetts Institute of Technology, Cambridge, MA, United States; Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, United Kingdom; National Centre for Atmospheric Science (NCAS), University of York, York, United Kingdom; Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States; Department of Chemistry, University of Colorado, Boulder, CO, United States; Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, CO, United States; School of Earth and Atmospheric Sciences, Georgia Tech, Atlanta, GA, United States; Centre for Atmospheric Science, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Simon Building, Brunswick Street, Man...
推荐引用方式 GB/T 7714	Zhu L.,Jacob D.J.,Eastham S.D.,et al. Effect of sea salt aerosol on tropospheric bromine chemistry[J],2019,19(9).
APA	Zhu L..,Jacob D.J..,Eastham S.D..,Sulprizio M.P..,Wang X..,...&Percival C.J..(2019).Effect of sea salt aerosol on tropospheric bromine chemistry.Atmospheric Chemistry and Physics,19(9).
MLA	Zhu L.,et al."Effect of sea salt aerosol on tropospheric bromine chemistry".Atmospheric Chemistry and Physics 19.9(2019).