气候变化领域集成服务门户(CCPortal): First insights into northern Africa high-altitude background aerosol chemical composition and source influences

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DOI	10.5194/acp-21-18147-2021
	First insights into northern Africa high-altitude background aerosol chemical composition and source influences
	Deabji N.; Fomba K.W.; El Hajjaji S.; Mellouki A.; Poulain L.; Zeppenfeld S.; Herrmann H.
发表日期	2021
ISSN	1680-7316
起始页码	18147
结束页码	18174
卷号	21 期号:24
英文摘要	Field measurements were conducted to determine aerosol chemical composition at a newly established remote high-altitude site in North Africa at the Atlas Mohammed V (AMV) atmospheric observatory located in the Middle Atlas Mountains. The main objectives of the present work are to investigate the variations in the aerosol composition and better assess global and regional changes in atmospheric composition in North Africa. A total of 200 particulate matter (PM10) filter samples were collected at the site using a high-volume (HV) collector in a 12h sampling interval from August to December 2017. The chemical composition of the samples was analyzed for trace metals, water-soluble ions, organic carbon (OC/EC), aliphatic hydrocarbons, and polycyclic aromatic hydrocarbon (PAH) contents. The results indicate that high-altitude aerosol composition is influenced by both regional and transregional transport of emissions. However, local sources play an important role, especially during low wind speed periods, as observed for November and December. During background conditions characterized by low wind speeds (avg. 3ms-1) and mass concentrations in the range from 9.8 to 12μgm-3, the chemical composition is found to be dominated by inorganic elements, mainly suspended dust (61%) and ionic species (7%), followed by organic matter (7%), water content (12%), and unidentified mass (11%). Despite the proximity of the site to the Sahara, its influence on the atmospheric composition at this high-altitude site was mainly seasonal and accounted for only 22% of the sampling duration. Biogenic organics contributed up to 7% of the organic matter with high contributions from compounds such as heneicosane, hentriacontane, and nonacosane. The AMV site is dominated by four main air mass inflows, which often leads to different aerosol chemical compositions. Mineral dust influence was seasonal and ranged between 21% and 74% of the PM mass, with peaks observed during the summer, and was accompanied by high concentrations of SO42- of up to 3.0μgm-3. During winter, PM10 concentrations are low (<30μgm-3), the influence of the desert is weaker, and the marine air masses (64%) are more dominant with a mixture of sea salt and polluted aerosol from the coastal regions (Rabat and Casablanca). During the daytime, mineral dust contribution to PM increased by about 42% because of road dust resuspension. In contrast, during nighttime, an increase in the concentrations of alkanes, PAHs, alkane-2-ones, and anthropogenic metals such as Pb, Ni, and Cu was found due to variations in the boundary layer height. The results provide the first detailed seasonal and diurnal variation of the aerosol chemical composition, which is valuable for long-term assessment of climate and regional influence of air pollution in North Africa. © 2021 Nabil Deabji et al.
语种	英语
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/246370
作者单位	Leibniz Institute for Tropospheric Research (TROPOS), Atmospheric Chemistry Department (ACD), Permoserstraße 15, Leipzig, 04318, Germany; LS3MN3E-CERNE2D, Faculty of Science, Mohammed V University in Rabat, 4 Avenue Ibn Battouta, B.P. 1040, Rabat, 10100, Morocco; Institut de Combustion Aérothermique Réactivité et Environnement/OSUC-CNRS, 1C Avenue de la Recherche Scientifique, Orleans Cedex 245071, France
推荐引用方式 GB/T 7714	Deabji N.,Fomba K.W.,El Hajjaji S.,et al. First insights into northern Africa high-altitude background aerosol chemical composition and source influences[J],2021,21(24).
APA	Deabji N..,Fomba K.W..,El Hajjaji S..,Mellouki A..,Poulain L..,...&Herrmann H..(2021).First insights into northern Africa high-altitude background aerosol chemical composition and source influences.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(24).
MLA	Deabji N.,et al."First insights into northern Africa high-altitude background aerosol chemical composition and source influences".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.24(2021).