气候变化领域集成服务门户(CCPortal): Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements

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DOI	10.5194/acp-22-11105-2022
	Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements
	Barreto, Africa; Garcia, Rosa D.; Guirado-Fuentes, Carmen; Cuevas, Emilio; Almansa, A. Fernando; Milford, Celia; Toledano, Carlos; Exposito, Francisco J.; Diaz, Juan P.; Leon-Luis, Sergio F.
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	11105
结束页码	11124
卷号	22 期号:17 页码:20
英文摘要	A comprehensive characterisation of atmospheric aerosols in the subtropical eastern North Atlantic has been carried out using long-term ground-based Aerosol Robotic NETwork (AERONET) photometric observations over the period 2005-2020 from a unique network made up of four stations strategically located from sea level to 3555m on the island of Tenerife. This site can be considered a sentinel for the passage of airmasses going to Europe from Africa, and therefore the aerosol characterisation performed here adds important information for analysing their evolution during their path toward Northern Europe. Two of these stations (Santa Cruz de Tenerife - SCO - at sea level and La Laguna - LLO - at 580ma.s.l.) are located within the marine atmospheric boundary layer (MABL), and the other two (Izana - IZO - at 2373ma.s.l. and Teide Peak - TPO - at 3555ma.s.l.) are high mountain stations within the free troposphere (FT). Monthly climatology of the aerosol optical depth (AOD), Angstrom exponent (AE), aerosol concentration, size distribution and aerosol optical properties has been obtained for the MABL and FT. Measurements that are quite consistent across the four sites have been used to categorise the main atmospheric scenarios, and these measurements confirm an alternation between predominant background conditions and predominant dust-loaded Saharan air mass conditions caused by seasonal dust transport over the subtropical North Atlantic. Background conditions prevail in the MABL and FT for most of the year, while dust-laden conditions dominate in July and August. The MABL under background conditions appears as a well-mixed layer with a low aerosol concentration (the volume concentration, VolCon, ranges from 0.02 +/- 0.01 to 0.04 +/- 0.02 mu m(3) mu m(-2)), a predominance of coarse-mode marine aerosols (the effective radius, R-eff, changes from 1.60 +/- 0.19 to 1.91 +/- 0.34 mu m), and a volume contribution of the fine-mode fraction Vf/Vt < 0 :35. The clean FT is characterised by remarkably low aerosol loading and a predominant impact of fine-mode aerosols throughout the year ( Vf/Vt has a maximum value of 0.93 +/- 0.13), with an average R-eff of 0.16 +/- 0.02 mu m. However, under dust-laden conditions and mainly in summer, we observe a predominance of coarse-mode aerosols with maximum VolCon values of 0.26 +/- 0.23 mu m(3) mu m(-2) for the MABL and 0.16 +/- 0.12 (0.06 +/- 0.05) mu m(3) mu m(-2) for IZO (TPO), and a similar and quite consistent fine-mode fraction of 0.12 +/- 0.03 in the vertical within the MABL and FT. Similarities in micro-physical and optical intensive aerosol properties confirm that the Saharan Air Layer (SAL) is a well-mixed layer in terms of the particulate composition. An estimation of the difference in the aerosol loading in the 1 km layer between IZO and TPO (in terms of VolCon and AOD) is performed in this study, and this shows that aerosol loading at IZO is double that at TPO, but they have similar fine-mode fractions, effective radii and intensive optical properties. The long-term trend analysis at SCO shows a significant negative trend in the fine-mode AOD between 2005 and 2020 ( -1.8 +/- 0.5) x 10(-5) yr(-1), which might be linked to the large reduction in oil-refining SO2 emissions from the SCO refinery in 2012.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000847716100001
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/273012
作者单位	Agencia Estatal de Meteorologia (AEMET); Centro de Investigacion Atmosferica de Izana (CIAI)
推荐引用方式 GB/T 7714	Barreto, Africa,Garcia, Rosa D.,Guirado-Fuentes, Carmen,et al. Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements[J],2022,22(17):20.
APA	Barreto, Africa.,Garcia, Rosa D..,Guirado-Fuentes, Carmen.,Cuevas, Emilio.,Almansa, A. Fernando.,...&Leon-Luis, Sergio F..(2022).Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(17),20.
MLA	Barreto, Africa,et al."Aerosol characterisation in the subtropical eastern North Atlantic region using long-term AERONET measurements".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.17(2022):20.