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DOI	10.5194/acp-20-13521-2020
	Distinct chemical and mineralogical composition of Icelandic dust compared to northern African and Asian dust
	Baldo C.; Formenti P.; Nowak S.; Chevaillier S.; Cazaunau M.; Pangui E.; Di Biagio C.; Doussin J.-F.; Ignatyev K.; Dagsson-Waldhauserova P.; Arnalds O.; Mackenzie A.R.; Shi Z.
发表日期	2020
ISSN	1680-7316
起始页码	13521
结束页码	13539
卷号	20 期号:21
英文摘要	Iceland is a highly active source of natural dust. Icelandic dust has the potential to directly affect the climate via dust-radiation interaction and indirectly via dust-cloud interaction, the snow/ice albedo effect and impacts on biogeochemical cycles. The impacts of Icelandic dust depend on its mineralogical and chemical composition. However, a lack of data has prevented an accurate assessment of the role of Icelandic dust in the Earth system. Here, we collected surface sediment samples from five major Icelandic dust hotspots. Dust aerosols were generated and suspended in atmospheric chambers, and PM10 and PM20 fractions were collected for further analysis. We found that the dust samples primarily consist of amorphous basaltic materials ranging from 8 wt%(from the Hagavatn hotspot) to 60 wt %-90 wt%(other hotspots). Samples had relatively high total Fe content (10 wt %-13 wt %). Sequential extraction of Fe to determine its chemical form shows that dithionite Fe (Fe oxides such as hematite and goethite) and ascorbate Fe (amorphous Fe) contribute respectively 1 %-6%and 0.3 %-1.4%to the total Fe in Icelandic dust. The magnetite fraction is 7 %-15%of total Fe and 1 %-2 wt%of PM10, which is orders of magnitude higher than in mineral dust from northern Africa. Nevertheless, about 80 %-90%of the Fe is contained in pyroxene and amorphous glass. The initial Fe solubility (ammonium acetate extraction at pH 4.7) is from 0.08%to 0.6 %, which is comparable to low-latitude dust such as that from northern Africa. The Fe solubility at low pH (i.e. pH 2) is significantly higher than typical low-latitude dust (up to 30%at pH 2 after 72 h). Our results revealed the fundamental differences in composition and mineralogy of Icelandic dust from low-latitude dust. We attribute these differences to the low degree of chemical weathering, the basaltic composition of the parent sediments and glacial processes. Icelandic dust contributes to the atmospheric deposition of soluble Fe and can impact primary productivity in the North Atlantic Ocean. The distinct chemical and mineralogical composition, particularly the high magnetite content (1 wt %-2 wt %), indicates a potentially significant impact of Icelandic dust on the radiation balance in the subpolar and polar regions. © Author(s) 2020.
语种	英语
scopus关键词	accuracy assessment; aerosol; basalt; chemical composition; iron; magnetite; mineral dust; mineralogy; sequential extraction; suspended particulate matter; Africa; Asia; Iceland
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/247384
作者单位	School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom; LISA, UMR CNRS 7583, Université Paris-Est Créteil, Université de Paris, Institut Pierre-Simon Laplace (IPSL), Créteil, France; Plateforme RX-UFR de Chimie, Université de Paris, Paris, France; Diamond Light Source, Didcot, Oxfordshire, United Kingdom; Agricultural University of Iceland, Keldnaholt, Reykjavik, Iceland; Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague, Czech Republic
推荐引用方式 GB/T 7714	Baldo C.,Formenti P.,Nowak S.,et al. Distinct chemical and mineralogical composition of Icelandic dust compared to northern African and Asian dust[J],2020,20(21).
APA	Baldo C..,Formenti P..,Nowak S..,Chevaillier S..,Cazaunau M..,...&Shi Z..(2020).Distinct chemical and mineralogical composition of Icelandic dust compared to northern African and Asian dust.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(21).
MLA	Baldo C.,et al."Distinct chemical and mineralogical composition of Icelandic dust compared to northern African and Asian dust".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.21(2020).