气候变化领域集成服务门户(CCPortal): PM2.5surface concentrations in southern West African urban areas based on sun photometer and satellite observations

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DOI	10.5194/acp-21-1815-2021
	PM2.5surface concentrations in southern West African urban areas based on sun photometer and satellite observations
	Léon J.-F.; Barthélémy Akpo A.; Bedou M.; Djossou J.; Bodjrenou M.; Yoboué V.; Liousse C.
发表日期	2021
ISSN	1680-7316
起始页码	1815
结束页码	1834
卷号	21 期号:3
英文摘要	Southern West Africa (SWA) is influenced by large numbers of aerosol particles of both anthropogenic and natural origins. Anthropogenic aerosol emissions are expected to increase in the future due to the economical growth of African megacities. In this paper, we investigate the aerosol optical depth (AOD) in the coastal area of the Gulf of Guinea using sun photometer and MODIS satellite observations. A network of lightweight handheld sun photometers have been deployed in SWA from December 2014 to April 2017 at five different locations in Côte d'Ivoire and Benin. The handheld sun photometer measures the solar irradiance at 465, 540 and 619 nm and is operated manually once per day. Handheld-sun-photometer observations are complemented by available AERONET sun photometer observations and MODIS level 3 time series between 2003 and 2019. MODIS daily level 3 AOD agrees well with sun photometer observations in Abidjan and Cotonou (correlation coefficient R = 0:89 and RMSE = 0.19). A classification based on the sun photometer AOD and Ångström exponent (AE) is used to separate the influence of coarse mineral dust and urban-like aerosols. The AOD seasonal pattern is similar for all the sites and is clearly influenced by the mineral dust advection from December to May. Sun photometer AODs are analyzed in coincidence with surface PM2.5 concentrations to infer trends in the particulate pollution levels over conurbations of Abidjan (Côte d'Ivoire) and Cotonou (Benin). PM2.5-to-AOD conversion factors are evaluated as a function of the season and the aerosol type identified in the AE classification. The highest PM2.5 concentrations (up to 300 μ gm-3) are associated with the advection of mineral dust in the heart of the dry season (December February). Annual means are around 30 μ gm-3, and 80 % of days in the winter dry season have a value above 35 μ gm-3, while concentrations remain below 16 μ gm-3 from May to September. No obvious trend is observed in the 2003 2019 MODIS-derived PM2.5 time series. However the short dry period (August September), when urban-like aerosols dominate, is associated with a monotonic trend between 0.04 and 0.43 μ gm-3 yr-1 in the PM2.5 concentrations over the period 2003 2017. The monotonic trend remains uncertain but is coherent with the expected increase in combustion aerosol emissions in SWA. © 2021 Author(s).
语种	英语
scopus关键词	aerosol; anthropogenic source; concentration (composition); MODIS; optical depth; particulate matter; photometer; satellite imagery; urban area; Abidjan; Atlantic Ocean; Benin [West Africa]; Cote d'Ivoire; Cotonou; Gulf of Guinea; Littoral [Benin]
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/247166
作者单位	Laboratoire d'Aérologie, Université Paul Sabatier, CNRS, Toulouse, France; Laboratoire de Physique du Rayonnement, Université d'Abomey Calavi, BP 526, Cotonou, Benin; Laboratoire de Physique de l'Atmosphère, Université Félix-Houphouët-Boigny, Abidjan, Cote d'Ivoire
推荐引用方式 GB/T 7714	Léon J.-F.,Barthélémy Akpo A.,Bedou M.,et al. PM2.5surface concentrations in southern West African urban areas based on sun photometer and satellite observations[J],2021,21(3).
APA	Léon J.-F..,Barthélémy Akpo A..,Bedou M..,Djossou J..,Bodjrenou M..,...&Liousse C..(2021).PM2.5surface concentrations in southern West African urban areas based on sun photometer and satellite observations.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(3).
MLA	Léon J.-F.,et al."PM2.5surface concentrations in southern West African urban areas based on sun photometer and satellite observations".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.3(2021).