气候变化领域集成服务门户(CCPortal): Interfacial supercooling and the precipitation of hydrohalite in frozen NaCl solutions as seen by X-ray absorption spectroscopy

CCPortal

DOI	10.5194/tc-15-2001-2021
	Interfacial supercooling and the precipitation of hydrohalite in frozen NaCl solutions as seen by X-ray absorption spectroscopy
	Bartels-Rausch T.; Kong X.; Orlando F.; Artiglia L.; Waldner A.; Huthwelker T.; Ammann M.
发表日期	2021
ISSN	19940416
起始页码	2001
结束页码	2020
卷号	15 期号:4
英文摘要	Laboratory experiments are presented on the phase change at the surface of sodium chloride-water mixtures at temperatures between 259 and 241 K. Chloride is a ubiquitous component of polar coastal surface snow. The chloride embedded in snow is involved in reactions that modify the chemical composition of snow as well as ultimately impact the budget of trace gases and the oxidative capacity of the overlying atmosphere. Multiphase reactions at the snow-air interface have been of particular interest in atmospheric science. Undoubtedly, chemical reactions proceed faster in liquids than in solids; but it is currently unclear when such phase changes occur at the interface of snow with air. In the experiments reported here, a high selectivity to the upper few nanometres of the frozen solution-air interface is achieved by using electron yield near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy. We find that sodium chloride at the interface of frozen solutions, which mimic sea-salt deposits in snow, remains as supercooled liquid down to 241 K. At this temperature, hydrohalite exclusively precipitates and anhydrous sodium chloride is not detected. In this work, we present the first NEXAFS spectrum of hydrohalite. The hydrohalite is found to be stable while increasing the temperature towards the eutectic temperature of 252 K. Taken together, this study reveals no differences in the phase changes of sodium chloride at the interface as compared to the bulk. That sodium chloride remains liquid at the interface upon cooling down to 241 K, which spans the most common temperature range in Arctic marine environments, has consequences for interfacial chemistry involving chlorine as well as for any other reactant for which the sodium chloride provides a liquid reservoir at the interface of environmental snow. Implications for the role of surface snow in atmospheric chemistry are discussed. © 2021 BMJ Publishing Group. All rights reserved.
英文关键词	atmospheric chemistry; atomic absorption spectroscopy; chemical reaction; detection method; marine environment; precipitable water; precipitation (chemistry); snow cover; sodium chloride; supercooling; Arctic Ocean
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202272
作者单位	Laboratory of Environmental Chemistry, Paul Scherrer Institut, Villigen PSI, Switzerland; Swiss Light Source (SLS), Paul Scherrer Institut, Villigen PSI, Switzerland; Department of Chemistry and Molecular Biology, Atmospheric Science, University of Gothenburg, Gothenburg, Sweden; Omya International AG, Oftringen, Switzerland
推荐引用方式 GB/T 7714	Bartels-Rausch T.,Kong X.,Orlando F.,et al. Interfacial supercooling and the precipitation of hydrohalite in frozen NaCl solutions as seen by X-ray absorption spectroscopy[J],2021,15(4).
APA	Bartels-Rausch T..,Kong X..,Orlando F..,Artiglia L..,Waldner A..,...&Ammann M..(2021).Interfacial supercooling and the precipitation of hydrohalite in frozen NaCl solutions as seen by X-ray absorption spectroscopy.Cryosphere,15(4).
MLA	Bartels-Rausch T.,et al."Interfacial supercooling and the precipitation of hydrohalite in frozen NaCl solutions as seen by X-ray absorption spectroscopy".Cryosphere 15.4(2021).